Published: 7 June 2020

MSc Sports Physiotherapy Dissertation

University of Bath, 2018

Abstract

Study Design

Cross-sectional design

Background

Repetitive overhead activity during tennis is a causative factor of shoulder pain. Age and playing years will influence shoulder movement and possibly result in shoulder injuries for throwers and hitting athletes. Literature assessing the shoulder movements of senior overhead athletes with shoulder pain exist, but correlation with serve kinematics is lacking.

Objectives

This study compares the effect of shoulder overhead activities on senior tennis player – with and without shoulder pain. The differences between movement patterns by means of inertial measurement and shoulder clinical assessments were assessed and correlated with the effect of age and playing history.

Methods

Twenty-two advanced level senior tennis players were divided into 2 groups: Older Asymptomatic group (OA), (n=12; males : females = 6 : 6; aged 56.6 ±8.3 years; 24.8 ±16.5 playing experience years), and Older Symptomatic group (OS), (n=10; males : females = 7 : 3; aged 53.7 ±13.6 years; 38.7 ±16.8 playing experience years).

A Clinical assessment (using an inclinometer) of glenohumeral internal rotation (GIR), glenohumeral external rotation, total range of motion (TROM) and scapula upward rotation were recorded.

A dynamometer determined muscle strength and ratios for shoulder Internal Rotators, External Rotators (ER), Middle and Lower Trapezius. Kinematics measures were collected during flat tennis serve by an inertial measurement system.

Results

By comparing between-groups humeral acceleration (Hum_a), OS-Hum_a was significantly increased by 42% (p<0.001). Both OA and OS-groups presented with reduced TROM and GIR.  OS-TROM and OS-GIR were significant inverse correlated (p<0.05, p<0.01) with OS-Hum_a. OS-Scapular Angular velocity (Scap_ω) and OS-Hum_ ω were elevated.

Conclusion

Age and Pain may have caused the OS-group to modify their technique due to a reduced OS-TROM and OS-GIR and an increased OS-Hum_a, Hum_ω and Scap_ω, causing stress on the shoulder joint and musculature.  It is important to promote shoulder mobility by including sleeper and cross-body posterior shoulder stretches.

Keywords

Tennis, overhead injury, kinematics

Related Articles

Shoulder Study Poster

Disclaimer

The contents of this article –  A Cross-Sectional Study Comparing Overhead Activities of Senior Tennis Players With and Without Shoulder Pain, is aimed at medical professionals. It is provided here for informational purposes only and should not be treated as medical or health management advice. The materials herein are not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your doctor, physiotherapist or other health care provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read in this article or website. Reliance on any information provided herein is solely at your own risk.

Copyright

The content of this article and dissertation – A Cross-Sectional Study Comparing Overhead Activities of Senior Tennis Players With and Without Shoulder Pain, is copyright © 2025 of Suegnet Meyer and Meyer & Associates Sports Physiotherapists. Transmission or reproduction of the contents, beyond that allowed by fair use as defined in the copyright laws requires the written permission of the copyright owners. Please provide proper attribution when referencing or sharing content.

The post A Cross-Sectional Study Comparing Overhead Activities of Senior Tennis Players With and Without Shoulder Pain first appeared on Meyer Physio.

Published: 16 August 2018

MSc Sports Physiotherapy – Poster for Dissertation

University of Bath, 2018

Poster for MSc dissertation 2018 – A cross-sectional study comparing overhead activities of senior tennis players with and without shoulder pain

Related Articles

A Cross-Sectional Study Comparing Overhead Activities of Senior Tennis Players With and Without Shoulder Pain

Disclaimer

The contents of this article and poster –  A Cross-Sectional Study Comparing Overhead Activities of Senior Tennis Players With and Without Shoulder Pain, is aimed at medical professionals. It is provided here for informational purposes only and should not be treated as medical or health management advice. The materials herein are not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your doctor, physiotherapist or other health care provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read in this article or website. Reliance on any information provided herein is solely at your own risk.

Copyright

The content of this article and poster – A Cross-Sectional Study Comparing Overhead Activities of Senior Tennis Players With and Without Shoulder Pain, is copyright © 2025 of Suegnet Meyer and Meyer & Associates Sports Physiotherapists. Transmission or reproduction of the contents, beyond that allowed by fair use as defined in the copyright laws requires the written permission of the copyright owners. Please provide proper attribution when referencing or sharing content.

The post Shoulder Study Poster first appeared on Meyer Physio.

Medial or inside elbow pain may be caused by performing repetitive badminton overhead smashing. These forceful strokes cause inside elbow stress on the elbow (or medial valgus stress), (Fleisig et al., 1996), and may have the following consequences: golfer’s elbow (flexor-pronator tear or tendinosis), nerve irritation (ulnar neuritis), or Ulnar Collateral Ligament (UCL) sprains or ruptures, (Bell, 2006). This ongoing stress on the elbow causes further damage by overloading the bony elbow structures at the back and cause loose bodies and more instability (Safran, 2004).

2. Risk factors to other players and how to prevention this injury

Badminton is explosive and consists of repetitive jumping and lunging. The player must perform fast directional changes with the racket-arm, doing combination of rapid arm throwing movements similar to baseball throwing or tennis serving. This causes excessive strain on the arm, (Faude et al., 2007). Male badminton players perform the smash frequently since this is a very effective way to score points. The inside elbow is stabilised against valgus stress, primarily by the UCL and to a lesser extent by the flexor-pronator complex (FPC), (Safran & Baillargeon, 2005). The UCL provides support against this valgus stress when the elbow is flexed between 20°-120°, and is under maximum stress when flexed at 70°. When the player plays frequently, the FPC becomes fatigued and cannot provide effective support to the inside elbow. This may result in micro-tears, inflammation and later cause FPC degeneration (tendinosis), (Ciccotti et al., 2004). While preforming the smash, valgus stress in the late cocking and early acceleration phase may produce medial sheering force of 300N, and 900N compression forces on the elbow. The UCL can only tolerate 64N safely, consequently it is prone to injury, (Flesig et al., 1995), especially with a faulty technique.

2.1 Faulty technique assessment within the kinetic chain

Faulty techniques can be identified by slow-motion video analysis of different strokes. Faulty techniques cause unnecessary strain on the body resulting in injury. By identifying the problem the coach can improve the technique, optimize force generation and reduce load on the elbow (Eygendaal et al., 2007). For example when excessive wrist flicking is performed during strokes, strain is caused on the FDC resulting in reduced force generation, (Sakurai & Ohtsuki, 2000). Skilled badminton players should use the shoulder and forearm rotation to produce force with lower energy cost to produce an effective smash, (Marshall & Elliott, 2000).
The kinetic chain describes a sequence of movements that follow-on from each other to produce the maximal amount of force, (Kibler et al., 2013). The legs produce force that is then transferred up the kinetic chain to the back, trunk, into the arm, and finally to the racket to produce a stroke. Video analysis can identify players with inadequate leg performance, reduced trunk rotation, poor core and scapular control, or incorrect sequencing of movements, which can then be corrected, (Wilk et al., 2012).

2.2 Fitness and skill

Fitness, skill, mental power, tactics, balance and coordination (neuro-muscular control (NMC)) are essential in badminton. Players train and play in an anaerobic energy system. Their anaerobic fitness should be tested regularly for optimum success during matches, (Chin et al., 1995). Skilled players reduce fatigue by resorting to the stored elastic energy of muscles (stretch-shortening cycle) of the shoulder rotators, (Genevois et al., 2013) and the forearm rotators, and the pre-stretching energy from quadriceps before jumping to perform the smash, (Tsai & Chang, 1998). This should be trained to increase efficiency.

2.3 High velocity versus gender

Baseball pitchers pitching with a higher ball velocity have an increased risk of elbow injury and receiving surgery, (Bushnell, 2010). Likewise, male badminton players perform frequent high velocity smashes. Males are able to do this due to a higher racket grip velocity and faster shoulder rotation, abduction and elbow extension to produce a faster smash, (Salim et al., 2010). UCL injuries are known to reduce shuttle accuracy and velocity, with lack of stamina and strength, (Safran, 2005), which may explain why AB’s performance was unsatisfactory in Malaysia.

2.4 Playing frequency and reduced upper limb range of motion (ROM)

Overuse injuries are usually quite common at the beginning of a new season when preseason conditioning was ineffective, or more towards the end of the season when the players are fatigued, (Jorgensen & Winge, 1990). Players that participate in competitions for longer than 8 months in the year are at risk of injury, (Shanley & Thigpen, 2013). Frequent, excessive volumes of overhead strokes reduce soft tissue flexibility, for instance: dominant shoulder inward rotation (IROM), (Wilk et al., 2011), and total shoulder rotation range of motion (TROM), that may cause additional stress on the inside elbow and UCL, (Eygendaal, 2007; Garrison et al., 2012). TROM and IROM are indicators of soft tissue restriction, (Couppe et al., 2014).
During excessive playing, elbow extension ROM reduces due to a flexor contracture or scarring that requires mobilisation, (Wilk et al., 2004). Identifying and improving restricted flexibility may promote upper limb biomechanical force production and translation with-in the kinetic chain, (Kibler, 2013).
Educating players about the importance of limiting excessive overhead activity, proper warm-up and maintaining flexibility whilst training may reduce injury, (Wilk, 2004). Screening and injury prevention programmes should be performed throughout the year to benchmark wrist, elbow and shoulder strength and ROM, monitor fitness and improve strength, endurance and flexibility to support the demands of badminton, (Ellenbecker et al., 2010; Shanley & Tightpin, 2013).

3. Management

Medial elbow pain should be assessed by taking a thorough patient history, physical assessment and imaging. Medial epicondylitis is indicated by pain and weakness with resisted wrist flexion and pronation. By pressing slightly below and to the front of the medial epicondyle causes pain, (Ciccotti et al., 2004). If numbness or weakness of the small and ring finger is present, nerve conductive tests needs to be performed to rule out ulnar neuritis, (Ciccotti, 2004). Alternatively referred pain from the neck may also be the cause, (Lee & Lee-Robinson, 2010). The ‘Milking manoeuvre’ test identifies valgus instability, (O’Driscoll et al., 2005). Dynamic ultrasound or MRI arthrogram is used to identify UCL injuries, flexor-pronator tears, tendinosis or calcification, (Azar et al., 2000; Nazarian et al., 2003).
Rehabilitation
Due to the sudden onset of pain and lack of performance, a UCL sprain is suspected. An initial non-surgical UCL rehabilitation consisting of an initial protected phase, intermediate phase, advance strength training phase and RTS is advised, (Modified guidelines: Wilk, 2012).

3.1 Initial protective phase

Aims:

• Reduce inflammation and pain
• Promote ligament healing
• Regain optimum pain free ROM
• Avoid muscle atrophy

1. Discontinue badminton with ‘active rest’. Avoid any further injury to the medial elbow structures for example heavy lifting and gripping. The kinetic chain needs to be taken into consideration and strong emphasis should be on core, scapular stability and shoulder strengthening, (Ellenbecker et al., 2009).
2. Treatment for the FPC: Ice and anti-inflammatory medication, transcutaneous electrical nerve stimulation, (Chesterton et al., 2009), and Cyriax treatment, (Trudel et al., 2004, Kohia et al., 2008) may reduce pain. Low intensity ultrasound increases protein synthesis, (Haker & Lundeberg, 1991), and laser treatment improves cell function, (Oken et al., 2008). Platelet rich plasma promotes UCL and FPC healing, (Halpernet et al., 2012; Podesta et al., 2013). Isometric elbow and wrist flexor and extensor exercises should be performed to avoid any further muscle wasting. Gentle stretching of the wrist flexors and pronators should be performed, (Wilk, 2004).
3. Elbow joint mobilisation: the physiotherapist may use Grade I-II mobilisation techniques and gradually progressing to Grade III-IV in weeks 3-4, to reduce pain and improve ROM (Maitland, 1987; Wilk, 2004).
4. Shoulder and arm strengthening: the concept of strengthening all components of the arm should apply. By strengthening the scapula stabilisers using high repetitions and low resistance endurance at varying speeds will be promoted. By applying manual resistance above the elbow, Serratus anterior, Trapezius and Rhomboids can be strengthened to provide stability, (Ellenbecker, 2009). Rotator cuff strengthening using manual resistance to activate the posterior cuff and scapular stabilisation during prone extension and horizontal abduction, (Wilk, 2013).
5. Lower limb and core strengthening: Leg press, squats and calve heel raises will promote force production in the lower limb kinetic chain. Additionally, progressing to lower limb plyometrics to increase the quadriceps elastic energy, improves power production with reduced fatigue during the single leg smash, (Tsai & Chang, 1998).

3.2 Intermediate phase

Aims:

• Maximise elbow range of motion and flexibility
• Improve strength and endurance
• Improve stability

The elbow joint capsule has a tendency to form adhesions with scarring of brachialis muscle. This needs to be reduced to maximise elbow extension by means of a low load, light resistance extension stretch for a duration of 10-15 minutes, 4 times per day. The arm, in pronation and elbow extension (figure 1), is attached to an elastic band providing a long duration light loaded (LDLL) stretch, (Wilk, 2004). This aim is to reach full elbow extension ROM at 3-4 weeks.

Figure 1: LDLL stretching (from: Ellenbecker et al., 2009)

2. Elbow flexion and extension: progression to concentric biceps and triceps strengthening can be introduced, if no pain is present. Concentric (muscle- shortening) triceps contraction improves racket velocity during the acceleration phase and needs to be trained, (Fleisig, 1995). During elbow extension the whipping effect may cause overload. Biceps need to be strengthened in an eccentric way (muscle lengthening) to oppose this, (Eygendaal, 2007).
3. The FPC provides dynamic elbow stability (Davidson et al 1995) and must be gradually loaded with concentric and then progressive ongoing eccentric loading, using elastic bands and light weights, (Cook & Purdam, 2009; Ellenbecker, 2010; Lewis, 2013 ) and continued stretching (Ellenbecker et al., 2002).
4. Posterior shoulder structures: sleeper stretch and the modified side-lying cross-body stretch mobilise the posterior shoulder structures. This can also be performed while the player is lying down, fixating the scapula and performing horizontal adduction across the chest, (Ludewig & Reynolds, 2009; Wilk, 2012; Shanley & Thigpen, 2013).
5. Myofacial release of the posterior shoulder structures and the forearm may improve mobility of the upper limb, (Travell & Simmons, 1999).
6. Upper limb rhythmic stabilisation that promotes dynamic stabilisation and neuromuscular control (NMC) may be increased and progressed to isotonic exercises, (Wilk, 2013).
7. Core stability and trunk rotational exercises must be performed for example medicine ball trunk rotation and swissball core strength training. Leg and core exercises that enhance NMC and flexibility that is specific to the needs of this player, for example hamstrings flexibility, (Shanley & Thigpen, 2013).

3.3 Advanced phase

Criteria for progression:

• Full pain-free ROM without any tenderness or laxity
• Elbow flexor & extensor strength improvements
• Good NMC and proprioception

Aims:

• To increase strength, power and endurance
• Improve NMC with progression to high speed drills

1. Progressive arm strength training: Thrower’s Ten isotonic programme should be followed to strengthen the upper limb with Theraband and dumbbells. This is a comprehensive programme to improve strength, endurance and power in preparation for overhead strokes, (Wilk, 2012).
2. Ongoing biceps and FPC eccentric training should be incorporated at varying speeds and loads.
3. Isokinetic training: Furthermore wrist and elbow isokinetic strength training can be implemented at speeds of 180’and 300’ per second for 15-20 repetitions to promote strength and endurance, (Ellenbecker, 1991; Ellenbecker, 2009). This includes concentric and eccentric training for the wrist flexors, pronators and eccentric elbow flexors in a protective capacity, (Lauder et al., 2012), as well as eccentric shoulder external rotation and concentric internal rotation, (Van Cingel et al., 2007).
4. Weight training: gym equipment may be introduced for bench-press, seated rowing and Latissimus Dorsi pull-downs, (Wilk, 2012).
5. Plyometrics must be carefully implemented without any discomfort, (Wilk, 2013; Ellenbecker, 2013). This can be done by wrist flicks and snaps (Figure 2). Distal arm strengthening with ball dribbling on the wall (Figure 3), and progress to internal shoulder rotation ball tossing (Figure 4), (Ellenbecker, 2013).
Figure 2: Wrist flicks (From: Ellenbecker, 2013)

6. Technique analysis: Video stroke technique analysis should be performed and errors should be corrected, (Wilk, 2004).
7. Interval badminton programme (IBP), (Wilk, 2004): by introducing the IBP, the phased return to sport is established and confidence promoted. Proper warm-up including flexibility should be introduced and consistently used in future, (Shanley & Thigpen, 2013). Correct stroke mechanisms as determined by the video analysis should be applied under the supervision of the coach. Efficient communication should exist between the athlete, coach and other rehabilitation professionals to ensure that effective progression is established and regression or re-injury is avoided.
Some discomfort during and after the implementation of the IBP is acceptable, however, the player needs to stop if pain is sharp and inform the physiotherapist, (Reinold et al., 2002). By using alternative days, the first week will be played at 50% of maximal stroke force during forearm and backhand while week 3-4 will be at 75% of maximum force with correct technique using forearm and backhand strokes. At week 3, power strokes are performed at 50% force. At 4-6 weeks 100% force of forearm and backhand strokes will be introduced with power strokes at 75%. Progressive amounts of each stroke will be performed. If this is successful, phased return to 3 games may be initiated. Again, gradual progression from 1.5 sets to full matches, without any elbow pain. The IBP must be introduced and progressed very carefully. If pain is present, the player needs to be reassessed and the management reconsidered, (Wilk, 2012).

Figure 3: Distal Arm Strength training with ball dribbling (From: Ellenbecker, 2013)

Figure 4: Internal shoulder rotation ball tossing (From: Ellenbecker, 2013).

3.4 Return to Sport may be considered after week 14

Criteria:

• Completed Thrower’s Ten programme, IBP and fitness testing.
• Pain free and full ROM, palpation & no laxity present
• Isokinetic ratios must be comparable to the non-dominant side. Comparative dominant elbow flexion strength should be 10-20% more while elbow extension ought to be 5-15% greater in elbow extension compared to the non-dominant side, (Wilk et al., 1993). Dominant side forearm pronation should measure 10-25% stronger, (Ellenbecker, 1991).

4. RTS Recommendations

If rehabilitation is successful, the player may compete after 12-14 weeks, with between-competition re-assessment to avoid re-injury, (Rettig et al., 2001; Wilk, 2004; Lavellee et al., 2013). Returning to competition will be on 17/06/14, with a phased return. The next competitions will be 14/10/14, 11/11/14 and 17/12/2014, to provide the player time to continue with further rehabilitation and avoid overloading. If, at 3 months of rehabilitation, ongoing medial elbow pain, UCL pathology or pain at 75% of hitting, is present, surgery should be considered, indicting an early season end, (Cain et al., 2010; Lavallee, 2013). The ‘Tommy John surgery’ rehabilitation is 11months, (Dodson et al., 2006).
Due to the excessive demand of badminton, all players are at risk, but especially males that perform a faster frequent smash, (Salim et al., 2010). Care should be taken to avoid overloading by participating too frequent in competitions, causing excessive fatigue. Good technique, warm-up and flexibility is important. Overhead activity should be limited. Regular screening that include assessing FPC symptoms or UCL laxity, should be performed.

5. Conclusion

Badminton players must perform all year round conditioning that includes strength training and fitness conditioning together with proper warm-up and stretching. The players should receive regular screening to assess shoulder and elbow ROM loss or FPC pain. Proper technique modifications may be helpful to avoid tissue overload, fatigue and complications.

References

• Azar, F.M., Andrews, J.R., Wilk, K.E., & Groh, D., (2000). Operative treatment of ulnar collateral ligament injuries of the elbow in athletes. The American Journal of Sports Medicine, 28(1):16–23.
• Azarbal, M., Adybeik, D., Ettehad, H., & Kia, M.A., (2003). A survey of elbow injuries in badminton players. The Internet Journal of Orthopaedic Surgery. 2(1):1.
• Bell., S. (2006). Elbow and Wrist Pain. In: P. Brukner & K. Khan(Eds), Clinical Sports Medicine Third Edition: 287-307. Australia: McGraw-Hill Professional.
• Bernas, G.A., Thiele, R.A.R., Kinnaman, K.A., Hughes R.E., Miller B.S., & Carpenter J.E., (2009). Defining safe rehabilitation for ulnar collateral ligament reconstruction of the elbow: a biomechanical study. The American Journal of Sports Medicine, 37(12):2392-2400.
• Bushnell, B.D., (2010). Association of Maximum Pitch Velocity and Elbow Injury in Professional Baseball Pitchers. The American Journal of Sports Medicine. 38(4):728-732.
• Cain, E.L., Andrews, J.R., Dugas, J.R., (2010). Outcome of ulnar collateral ligament reconstruction of the elbow in 1281 athletes: results in 743 athletes with minimum 2-year follow-up. The American Journal of Sports Medicine. 38(12):2426-2434.
• Chin, M., Wong, A.S.K., So, R.C.H., Siu, O.S., Steininger, K., & Los, D.T.L., (1995). Sport specific fitness testing of elite badminton players. British Journal of Sports Medicine. 29(3):153-157.
• Ciccotti, M.C., Schwarts, M.A., Ciccitti M.G., (2004). Diagnosis and treatment of medila epicondylitis of the elbow. Clinics in Sports Medicine. 23:693-705.
• Conway, J.E., Jobe, F.W., & Glousman, R.E., (1992). Medial instability of the elbow in throwing athletes. Treatment by repair or reconstruction of the ulnar collateral ligament. The Journal of Bone and Joint Surgery 74(1):67-83.
• Cook, J.L., & Purdam, C.R., (2009). Is tendon pathology a continuum? A pathology model to explain the clinical presentation of load-induced tendinopathy. British Journal of Sports Medicine. 43(6):409–416.
• Couppé, C., Thorborg, K., Hansen, M., Fahlström, M., Bjordal, J.M., Nielsen, D., Baun, M.,Storgaard, M., & Magnusson, S.P., (2014). Shoulder rotational profiles in young healthy elite female and male badminton players. Scandinavian Journal of Medicine & Science in Sports. 24(1):122-128.
• Chesterton, L.S., van der Windt, D.A., Sim, J., Lewis, M., Mallen, C.D., Mason, E.E., Warlow, C., Vohora, K., & Hay, E.M., (2009). Transcutaneous electrical nerve stimulation for the management of tennis elbow: a pragmatic randomized controlled trial: the TATE trial. BMC Musculoskeletal Disorders. 10:156.
• Davidson, P.A.., Pink, M., & Perry J., (1995). Functional anatomy of flexor pronator muscle group in relation to the MCL. The American Journal of Sports Medicine. 23(2):245-250.
• Dodson, C.C., Thomas, A., Dines, J.S., Nho, S.J., Williams, R.J., & Altchek, D.W., (2006). Medial ulnar collateral ligament reconstruction of the elbow in throwing athletes. The American Journal of Sports Medicine. 34(12):1926–1932.
• Ellenbecker, T.S., Mattalino, A.J., Elam, E.A., & Caplinger, R.A., (1998). Medial elbow joint laxity in professional baseball pitchers. A bilateral comparison using stress radiography. The American Journal of Sports Medicine. 26(3):420-424.
• Ellenbecker T.S., (1991). A total arm strength isokinetic profile of highly skilled tennis players. Isokinetics and Exercise Science. 1(1):9–21.
• Ellenbecker T.S., Roetert E.P., Bailie, D.S., Davies, G.J., & Brown, S.W., (2002). Glenohumeral joint total rotation range of motion in elite tennis players and baseball pitchers. Medicine and Science in Sports and Exercise. 34(12):2052-2056.
• Ellenbecker, T.S., Wilk, K.E., Altchek, D.W., & Andrews, J.R., (2009). Current Concepts in Rehabilitation Following Ulnar Collateral Ligament Reconstruction. Sports Health. 1(4):301-313.
• Ellenbecker, T.S., Pieczynski, T.E., & Davies, G.J., (2010). Rehabilitation of the elbow following a sports injury. Clinics in Sports Medicine. 29(1):33-60.
• Ellenbecker, T.S., Nirschl, R., & Renstrom, P., (2013). Current concepts in examination and treatment of elbow tendon injuries. Sports Health. 5(2):186-194.
• Elliott, B.C., Baxter, K.G., & Besier, T.F. (1999). Internal rotation of the upper-arm segment during a stretch-shortening cycle movement. Journal of Applied Biomechanics. 15(4):381-395.
• Elliot, B., (2006). Biomechanics and tennis. British Journal of Sports Medicine. 40(5):392-396.
• Eygendaal, D., Rahussen, F.T.G., & Diercks, R.L., (2007). Biomechanics of the elbow joint in tennis players and relation to pathology. British Journal of Sports Medicine. 41(11):820-823.
• Faude, O., Meyer, T., Rosenberger, F., Fried, M., Huber, G., & Kindermann, W., (2007). Physiological characters of badminton match play. European Journal of Applied Physiology. 100(4):479-485.
• Floris, S., Olsen, B.S., Dalstra, M., Sojbjerg, J.O., & Sneppen, O., (1998). The medial collateral ligament of the elbow joint: anatomy and kinematics. Journal of Shoulder Elbow Surgery. 7(4):345–351.
• Fleisig, G.S., Andrews, J.R., & Dillman, C.J., (1995). Kinetics of baseball pitching with implications about injury mechanisms. The American Journal of Sports Medicine. 23(2):233-239.
• Garrison, J.C., Cole, M.A., Conway, J.E., Macko, M.J., Thigpen, C., Shanley, E., (2012). Shoulder Range of Motion Deficits in Baseball Players with an Ulnar Collateral Ligament Tear. American Journal of Sports Medicine. 40(11):2597-2603.
• Genevois, C., Frican, B., Creveaux, T., Hautier, C., & Rogowski, I., (2013). Effects of two training protocols on the forehand drive performance in tennis. Journal of Strength and Condinioning Research. 27(3): 677–682.
• Glousman, R.E., Barron, J., & Jobe, F.W., (1992). An electromyographic analysis of the elbow in normal and injured pitchers with medial collateral ligament insufficiency. The American Journal of Sports Medicine. 20(3):311–317.
• Groppel, J.L., & Nirschl, R.P., (1986). A mechanical and electromyographical analysis of the effects of counter force braces on the tennis player. The American Journal of Sports Medicine. 14(3):195-200.
• Haker, E., & Lundeberg, T., (1991). Pulsed ultrasound treatment in lateral epicondylalgia. Scandinavian Journal of Rehabilitation Medicine. 23(3):115–118.
• Halpern, B.C., Chaudhury, S., & Rodeo, S.A., (2012). The role of platelet-rich plasma in inducing musculoskeletal tissue healing. The Musculoskeletal Journal of Hospital and Special Surgery. 8(2):137-145.
• Han, K.J., Kim, Y.K., Lim, S.K., Park, J.Y., & Oh, K.S., (2009). The effect of physical characteristics and field position on the shoulder and elbow injuries of 490 baseball players: confirmation of diagnosis by magnetic resonance imaging. Clinical Journal of Sport Medicine. 19(4):271-276.
• Jørgensen, U., & Winge, S., (1990). Injuries in Badminton. Sports Medicine. 10(1):59-64.
• Kibler, W.B., (1994). Clinical biomechanics of the elbow in tennis: implications for evaluation and diagnosis. Medicine and Science in Sports and Exercise. 26(10):1203-1206.
• Kibler, W.B., & Sciascia, A., (2004). Kinetic chain contributions to elbow function and dysfunction in sports. Clinics in Sports Medicine. 23:545-552.
• Koh, J.L., Schafer, M.F., Keuter, G., & Hsu, J.E., (2006). Ulnar collateral ligament reconstruction in elite throwing athletes. Arthroscopy. 22(11):1187–1191.
• Kohia, M., Brackle, J., Byrd, K., Jennings, A., Murray, W., & Wilfong, E., (2008). Effectiveness of physical therapy treatments on lateral epicondylitis. Journal of Sport Rehabilitation. 17(2):119-136.
• Laudner, K.G., Wilson, J.T., & Meister, K., (2012). Elbow isokinetic strength characteristics among collegiate baseball players. Physical Therapy in Sport. 13(2):97-100.
• Lavallee, M.E., Sears, K., & Corrigan, A., (2013). The evaluation and treatment of elbow injuries. Primary Care Clinical Office in Practice. 40(2):407-429.
• Lee, A.T., & Lee-Robinson, A.L., (2010). The prevalence of medial epicondylitis among patients with C6 and C7 radiculopathy. Sports Health. 2(4):334-336.
• Lewis, J., & McCreesh, K., (2013). Continuum model of tendon pathology – where are we now? International Journal of Experimental Pathology. 94(4):1365-2613.
• Lin, F., Kohli, N., Perlmutter, S., Lim, D., Nuber, G.W., & Makhsous, M., (2007). Muscle contributions to elbow joint valgus stability. Journal of Shoulder and Elbow surgery. 16(6):795-802.
• Ludewig, P. M., & Reynolds, J. F. (2009). The association of scapular kinematics and glenohumeral joint pathologies. The Journal of orthopaedic and sports physical therapy. 39(2):90-104.
• Marshall, R.N., & Elliott, B.C., (2000). Long-axis rotation: the missing link in proximal-to-distal segmental sequencing. Journal of Sports Science. 18(4):247–254.
• Maitland, G.D., (1987). Upper Limb: Elbow. In: G.D. Maitland(Eds.), Peripheral Manipulation Second Edition. 121-136. Butterworths, London.
• Nazarian, L.N., McShane, J.M., & Ciccotti, M.G., (2003). Dynamic ultrasound of the anterior band of the ulnar collateral ligament in asymptomatic major league baseball pitchers. Radiology. 227(1):149–154.
• Ng, G.Y.F., & Lam, P.C.W., (2002). A study of Agonist/Antoginist Isokinetic work ratios of shoulder rotators in Men who play badminton. Journal of Orthopaedic Sports Physical Therapy. 32(8):399-404.
• O’Driscoll, S.W.M., Lawton, R.L., & Smith, A.M., (2005). The “moving valgus stress test” for medial collateral ligament tears of the elbow. The American Journal of Sports Medicine. 33(2):231-239.
• Oken, O., Kahraman, Y., & Ayhan, F., (2008). The short-term efficacy of laser, brace, and ultrasound treatment in lateral epicondylitis: a prospective, randomized, controlled trial. Journal of Hand Therapy. 21(1):63–67.
• Osbahr, D.C., Swaminathan, S.S., Allen, A.A., Dines, J.S., Coleman, S.H., & Altcken, D.W., (2010). Combined Flexor-pronator mass and Ulnar collateral ligament injuries in the elbow of older baseball players. The American Journal of Sports Medicine. 38(4):733-739.
• Podesta, L., Crow, S.A., & Volkmer, D. (2013). Treatment of Partial Ulnar Collateral Ligament Tears in the Elbow with Platelet-Rich Plasma. The American Journal of Sports Medicine. 41(7):1689-1694.
• Radwan, Y.A., ElSobhi, G., & Badawy, W.S., (2008). Resistant tennis elbow: shock-wave therapy versus percutaneous tenotomy. International Orthopaedics . 32(5):671–677.
• Regan, W.D., Korinek, S.L., Morrey, B.F., & An, K.N., (1991). Biomechanical study of ligaments around the elbow joint. Clinical Orthopaedics and Related Research. 271:170–179.
• Reinold, M.M., Wilk, K.E., Reed, J., Crenshaw, K., & Andrews, J.R., (2002). Interval Sport Programs: Guidelines for Baseball, Tennis, and Golf. Journal of Orthopaedic and Sport Physical Therapy. 32(6):293-298.
• Rettig, A.C., Sherrill, C., Snead, D.S., Mendler, J.C., & Mieling, P., (2001). Non-operative treatment of ulnar collateral ligament injuries in throwing athletes American Journal of Sports Medicine. 29(1):15-17.
• Rudzki, J.R., & Paletta, G.A., (2004). Juvenile and adolescent elbow injuries in sport. Clinics in Sports Medicine. 23(4):581-608.
• Safran, M.R., (2004). Ulnar collateral ligament injury in the overhead athlete: diagnosis and treatment. Clinics in Sports Medicine. 23(4):643-663.
• Safran, M.R., & Baillargeon D., (2005). Soft-tissue stabilisers of the elbow. Journal of Shoulder and Elbow Surgery. 14(1):S179-S185.
• Sakurai, S., & Ohtsuki, T., (2000). Muscle activity and accuracy of performance of the smash stroke in badminton with reference to skill and practice. Journal of Sport Sciences. 18(11):901-914.
• Salim, M.S., Lim, H.N., Salim, M.S.M., & Baharuddin M.Y., (2010). Motion analysis of arm motion during badminton smash. Biomedical Engineering and Sciences: IEEE EMBS Conference. 10: 111-114.
• Seiber, K., Gupta, R., McGarry, M.H., Safran, M.R., & Lee, T.Q., (2009). The role of the elbow musculature, forearm rotation and elbow flexion in elbow stability: An in vitro study. Journal of Shoulder and Elbow Surgery. 18(2):260-268.
• Shariff, A.H., George, J., & Ramlan, A.A., (2009). Musculoskeletal injuries among Malaysian badminton players. Singapore Medical Journal. 50(11):1095-1100.
• Shaneley, E., & Tigpen, C., (2013). Throwing injuries in the adolescent athlete. International Journal of Sports Physical Therapy. 8(5):630-640.
• Søjbjerg, J.O., Ovesen, J., & Nielsen, S., (1987). Experimental elbow instability after transection of the medial collateral ligament. Clinical Orthopaedics, (218):186–190.
• Svernlöv, A.B., & Adolfsson, L. (2001). Non-operative treatment regime including eccentric training for lateral humeral epicondylalgia. Scandinavian Journal of Medicine & Science in Sports. 11(6):328-334.
• Taylor, S.A., & Hannafin, J.A., (2012). Evaluation and management of elbow tendinopathy. Sports Health. 4(5):384-393.
• Travell, J.G., & Simmons, D.G., (1999). Shoulder and arm pain In: Myofacial pain and dysfunction. Second edition: 565-577. Williams & Wilkins, Pennsylvania.
• Tsai, C.L., Chang, S.S., (1998). Biomechanical analysis of differences in the badminton smash and jump smash between Taiwan elite and collegiate players. Proceedings of the XVI International Symposium on Biomechanics in Sports. Germany. 259-262.
• Trudel, D., Duley, J., Zastrow, I., Kerr, E.W., Davidson, R., & MacDermid, J.C., (2004). Rehabilitation for patients with lateral epicondylitis: a systematic review. Journal of Hand Therapy. 17(2):243-266.
• Udall, J.H., Fitzpatrick, M.J., McGarry, M.H., Leba, T.B., & Lee, T.Q., (2009). Effects of flexor-pronator muscle loading on valgus stability of the elbow with an intact, stretched, and resected medial ulnar collateral ligament. Journal of Shoulder Elbow Surgery. 18(5):773-778.
• Van Cingel, R., Kleinresink, G.J., Mulder, P., De Bie, R., & Kuipers, H., (2007). Isokinetic strength values, convenitional ration and dynamic control ration of shoulder rotator muscles in elite badminton players. Isokinetics and Exercise Science. 15(4):287-293.
• Wilk, K.E., Arrigo, C.A., & Andrews, J.R., (1993). Rehabilitation of the elbow in the throwing athlete. Journal of Orthopaedic Sports Physical Therapy. 17(6):305–317.
• Wilk, K.E., Reinold, M.M., & Andrews, J.R., (2004). Rehabilitation of the throwers elbow. Clinical Sports Medicine. 23(4):765-801.
• Wilk, K.E., Yenchak, A.J., Arrigo, C.A., & Andrews, J.R., (2011). The Advanced Throwers Ten Exercise Program: a new exercise series for enhanced dynamic shoulder control in the overhead throwing athlete. Physician and Sportsmedicine. 39(4):90-97.
• Wilk, K.E., Macrina, L.C., Cain, E.L., Dugas, J.R., & Andrews, J.R., (2012). Rehabilitation of the overhead athlete’s elbow. Sports Health. 4(5):404-414.
• Wilk, K.E., & Macrina, L.C., (2013). Non-operative and postoperative rehabilitation for gleno-humeral instability. Clinics in Sports Medicine. 32(4):865-914.
• Wright, R.W., Steger-May, K., Wasserlauf, B.L., O’Neal, M.E., Weinberg, B.W., & Paletta, G.A., (2006). Elbow range of motion in professional baseball pitchers. American Journal of Sports Medicine. 34(2):190-193.
• Zouzias, I.C., Byram, I.R., Shillingford, J.N., & Levine, W.N., (2012). A Primer for Physical Examination of the Elbow. The Physician and Sports Medicine. 40(1):951-962.

Disclaimer

The contents of this article – Prevention and Rehabilitation of Thrower’s Elbow, is aimed at medical professionals. It is provided here for informational purposes only and should not be treated as medical or health management advice. The materials herein are not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your doctor, physiotherapist or other health care provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read in this article or website. Reliance on any information provided herein is solely at your own risk.

Copyright

The content of this article – Prevention and Rehabilitation of Thrower’s Elbow, is copyright © 2016 of Suegnet Meyer and Meyer & Associates. Transmission or reproduction of the contents, beyond that allowed by fair use as defined in the copyright laws requires the written permission of the copyright owners.

The post Prevention and Rehabilitation of Thrower’s Elbow first appeared on Meyer Physio.

Author: Suegnet Meyer

Introduction

The Anterior Cruciate Ligament (ACL) is the primary knee stabiliser that prevents anterior laxity of the tibia in relation to the femur and provides rotational knee stability (Negus et al., 2012). In the United States, approximately 200,000 Anterior Cruciate Ligament Reconstructions (ACLR) are performed annually at a cost of $3 billion (Brophy et al., 2009). Devastating evidence estimates up to 10% of professional alpine skiers will end their careers due to ACL ruptures or tears (Pujol et al., 2007).

Aim

This Clinical Guidance is aimed at Physiotherapists, Strength & Conditioning Coaches and Doctors to prevent and manage ACL ruptures during professional downhill, freestyle skiing and ski-cross during off-season.

Method

A search was performed on Cochrane Collaboration, the York Centre for Reviews and Dissemination, and the United States Agency for Health Care Policy and Research. These systematic reviews provided guidelines to create this evidence based tool. The level of evidence is graded according to criteria described by the Centre of Evidence Based Medicine Oxford United (CEBM) (http://www.cebm.net/). See Figure 1. Evidence strength was rated according to Guyatt et al. (1995).

	Level 1 Evidence
	Level 2 Evidence
	Level 3 Evidence

FIGURE 1: Level of evidence according to CEBM

Clinical Guidelines recommendations

• Conservative versus Surgical treatment
• Timing of Surgery
• Prehabilitation
• Single versus Double bundle techniques
• Grafts choices
• Outcome measurements
• Cryotherapy
• Therapeutic exercise
• Accelerated versus Non-Accelerated rehabilitation
• Open versus Closed chain exercises
• Neuromuscular Training
• Neuromuscular Electrical Stimulation
• Knee Bracing
• Home-based versus Supervised rehabilitation
• Injury prevention

Injury Incidence

No decline in ACL injuries and re-injury rates in professional alpine skiers is reported (Pujol, 2007). This statistics shows primary ACL injury rate at 5.7 per 100 skier-seasons with a 19% re-injury rate and a bilateral ACL injury incidence of 30.5%. During professional skiing, these injuries affect both sexes equally (Pujol, 2007; Westin et al., 2012). In contrast, more female recreational skiers sustain ACL injuries (Flørenes et al., 2009).

Injury Mechanism

Professional skiers endure deceleration from high speeds, jumping, cutting and pivoting, placing stress on the knees resulting in non-contact ACL injuries (Griffin et al., 2006). Injuries occur during hard landings when rigid ski boots induce tibial anterior drawer injuries (Natri et al., 1999; Flørenes, 2009), while the athletes assume seated posture and quadriceps contracts maximally (Johnson 1995). Bere et al., (2014) described the “slip-catch” mechanism: the skier loses balance backwards or inwards during turning. The inside edge of the outer ski catches the snow causing forced valgus and tibial internal rotation position.

Intervention

1. Conservative versus Surgical Management

Cochrane reported inconclusive evidence of ACL injury management (Linko et al., 2005).
Using a pre-screening criteria can determine the ‘copers’ or ‘non-copers’, indicating who will return to sport (RTS) without surgery (Fitzgerald et al., 2000; Hurd et al., 2008; Logerstedt et al., 2010a). These potential ‘copers’ can be conservatively managed by perturbation neuromuscular training (NMT) (Fitzgerald, 2000). However, this will be a minority of skiers that may be considered for short term conservative management to complete a season (Fitzgerald, 2000).
Anterior Cruciate Ligament Reconstruction (ACLR) is indicated for active adolescents with a good prognosis of 85% to RTS. It is unlikely for active adolescents to return to the same sporting level with conservative management only (Ramski et al., 2013).
ACLR is cost-effective, at $38,121 per repair in comparison to rehabilitation alone that may include knee instability risk at $88,538. (Lubowitz et al., 2011; Mather et al., 2013).

Surgical management is indicated for active adolescents wanting to return to high level sport. ACLR is more cost-effective than rehabilitation only.

2. Timing of Surgery

Optimal surgical timing is controversial. Ideally the outcome must be optimised with minimal post-operative complications.
A systematic review demonstrated surgery may be performed from 2 days post-trauma (Andernord et al., 2013). Another review found that ACLR can be performed from one week post-injury together with a moderately accelerated programme with a low post-operative stiffness risk (Kwok et al., 2013).
Rapid surgical intervention after an acute ACL rupture may cause arthrofibrosis (Cosgarea et al., 1995; Mauro et al., 2008). Delaying surgery for high-level athletes, or athletes with increased knee instability post-injury, may cause secondary meniscal injuries and degenerative Osteoarthritis (OA) (Beynnon et al., 2005; Amin et al., 2008; Ajuied et al., 2013). Post-surgical complications include deep vein thrombosis (Ramos et al., 2008) and septic arthritis (Van Tongel et al., 2007).

Surgery should not be performed too soon due to arthrofibrosis risk but a lengthy delay may cause OA or meniscal injuries.

3. Prehabilitation

Prehabilitation aims to enhance postoperative outcome. Aims and criteria for progression to surgery include: Minimal knee swelling, full range of motion (ROM) including knee extension, normal gait and Quadriceps strength (Ditmeyer et al., 2002).
A pre-operative 6-week home-based and gym programme consisting of NMT and strengthening programme resulted in enhanced postoperative outcomes. Pre-operative improvements (hop tests and quadriceps hypertrophy) were evident. These enhancements were still present 12-weeks post-operative (Shaarani et al., 2013).

A prehabilitation programme will enhance the post-operative outcome up to 12 weeks.

4. Surgical technique: Double-Bundle (DB) or Single-Bundle (SB) choice

The ACL consists of 2 distinct bundles. The ACLR is performed by drilling either a single or double tunnel through the tibia and femur, to pass the graft through.
Cochrane reported no difference in outcome scores when performing SB compared to DB ACLR (Tiamklang et al., 2012; Bjornsson et al., 2013; Xu et al., 2013).
A meta-analysis showed DB as the superior technique since it provides better rotational stability. This may not affect the functional outcome compared to SB (Li et al., 2014). DB may reduce re-rupture rates but is more invasive and technically demanding (Tiamklang, 2012).
In the short term, DB is cost-effective due to low revision rates. However, long term follow-up is indicated (Paxton et al., 2010).

Effective DB technique improves rotational stability, less re-rupture rates and has short term cost-effectiveness, compared to SB technique.

5. Grafts Choices

Cochrane reviews demonstrate no significant difference of knee stability is achieved when using either Hamstring (HT) or Patella tendon (BPTB) graft techniques (Liden et al., 2007; Maletis et al., 2007; Magnussen et al., 2011; Mohtadi et al., 2011).
After discussion with the patient, the surgeon will choose the suitable graft. Consideration should be: type of sport, age, accelerated rehabilitation and RTS (Magnussen, et al., 2010; Rahr-Wagner, et al., 2014).
The more frequently the surgeon performs ACLR the better the outcome. Surgeons with a lower volume ACLR (52 ACLR in 12 months) (Lyman et al., 2009). Hospitals hosting two or fewer ACLR monthly are 32% more likely to have a 90-day post-operative readmission, in contrast to hospitals performing more than 10 ACLR monthly (Lyman, 2009).

ACLR using HT and BPTB showed identical knee stability outcomes.

Different types of grafts

Various graft types are available:

• Autografts
• Allografts
• Artificial grafts

a. Autografts (harvested from the patient)

Hamstring graft (HT)

• Surgical suspension fixation is used. This may increase longitudinal movement between fixation point and graft resulting in bone tunnel enlargement, compromising knee stability (Webster et al., 2001).
• Reduces knee flexion and internal rotation strength.
• Takes longer to heal (9-12 weeks)(Weiler et al., 2002) causing later RTS.
• Additional infection risk (Maletis et al., 2013b).
• Although more popular due to lower donor morbidity, the revision rate during the first year is higher in youngsters (Maletis et al., 2013a; Persson et al., 2014), and re-rupture rate is (1.82 time higher) for the age group

Patella tendon graft (BPTB)

• A screw-in fixation is used (Anderson et al., 2001).
• Complications: anterior knee pain, patella fractures, inability to kneel.
• Heals faster (6 weeks) than HT (Papageorgiou et al., 2001) and quicker RTS (Weiler et al., 2002).
• Used in younger age group (<20 years) when accelerated rehabilitation is required (Magnussen et al., 2010).
• Causes less OA due to increased stability ((Li et al., 2012; Rahr-Wagner, 2014).

b. Allograft (harvested from external donor)

ACLR performed with fresh frozen allograft that has not been chemically treated or irradiated, produced equivalent clinical outcome compared to autografts (Lamblin et al., 2013).

c. Artificial Grafts: Ligament Advance Reinforcement System (LARS)

LARS is a polyester graft that compares well to BPTB. It may be used in athletes performing high demanding sport with a 6-months RTS (Pan et al., 2013). It may cause post-operative synovitis (Klein et al., 1992). Uncertainty exists over long term OA risk (Pichon et al., 2007).

Autografts and untreated fresh frozen allografts produce similar clinical outcome.

6. Outcome measurement

Hop tests

Standardised functional outcome measures determine rehabilitation progression and RTS. The single-limb hop tests measure neuromuscular ability and dynamic knee stability, and demonstrates good test-retest reliability (ICC) in normal young subjects (Noyes et al., 1991; Ross et al., 2002).
During ACL rehabilitation the hop tests measured with good reliability and validity (7.05% – 12.96%) (Reid et al., 2007).

Patient assessed health outcome

Various patient-assessed health instruments with varying validity, measures patients’ perception of the ACLR outcome.
The Knee Injury and Osteoarthritis Outcome Score(KOOS) measures symptoms and disability with responsiveness values (MDC95) to change: pain, symptoms, daily living activities, sport and recreational and knee specific quality of life, but lacked addressing mental health domains(Garratt et al., 2004; Wright, 2009; Logerstedt et al., 2010a).
International Knee Documentation Committee 2000 form(IKDC) is a joint-specific outcome that measures symptoms, function, and sports activity aimed at various knee ailments with good test-retest value especially in bigger groups (Collins et al., 2011; Logerstedt 2010a). However, Irrgang et al.(2006), demonstrated that due to higher MDC95- values, responsiveness may be compromised.
The Knee Outcome Survey-Activities of Daily Living Scale(KOS-ALDS) is responsive to knee functional assessment with good test-retest (ICC 0.97) and minimal detectable changed values for MDC95 (Irrgang et al., 1998).

KOOS, IKDC or KOS-ALDS, and Hop tests may be used to assess pain, disability, function and clinical presentation changes during rehabilitation. Effective communication between the patient and the MDT will optimise rehabilitation and outcome to RTS.

Rehabilitation Interventions

7. Cryotherapy

Cryotherapy is used for post-operative pain and swelling reduction and to promote knee ROM and drainage. Evidence confirmed the cryotherapeutic analgesic effect, however no change was shown for ROM or drainage (Raynor et al., 2005).

It is recommended that cryotherapy is used for pain relief immediate post-operative and ongoing during the first weeks of rehabilitation.

8. Therapeutic Exercise

Eccentric, concentric and NMT is used during rehabilitation to improve quadriceps contractions.
Eccentric rehabilitation is effective to improve quadriceps strength. NMT improves motor learning in addition to strength training. Eccentric training improves quadriceps strength better than concentric exercises (Gokeler et al., 2013).

Rehabilitation should be a combination of concentric, eccentric, and NMT.

9. Accelerated Versus Non-accelerated rehabilitation

Shelbourne & Nitz (1990), described accelerated rehabilitation by initially aiming to restore full weight bearing, knee extension and optimising quadriceps activity.
According to a study, 85% of participant with BPTB accelerated group (19-weeks) and non-accelerated BPTB group (32-weeks), showed almost equivalent anterior posterior laxity (1.3mm difference) after the first 3-months, postoperative. After the two year follow-up the outcome were again similar for both groups (Beynnon et al., 2011).

19-week accelerated rehabilitation is possible when using BPTB ACLR.

10. Open Kinetic (OKC) and Closed Kinetic Chain exercises (CKC)

OKC is performed while the foot is not planted, by performing leg extensor resistance training using ankle weights. OKC increases anterior tibial translation (Beynnon et al., 1997), which may result in increased graft stress causing knee laxity. However, OKC may increase quadriceps torque, resulting in accelerated rehabilitation and RTS.
During CKC the foot is supported by using a leg-press machine (Andersson et al., 2009). CKC promotes joint compression and knee stability (Beynnon et al., 1997).
Uncertainty exists in the quantity of quadriceps loading that can safely be applied to gain quadriceps strength improvements in HT graft rehabilitation. During the initial HT post-surgical phase, graft necrosis takes place causing optimum graft weakness at 6-8 weeks (Scheffler et al., 2008). HT graft stress would cause more instability and needs to be protected.
OKC for HT graft, from 90-45° knee flexion can be safely performed from 4-weeks post-operatively without stressing the HT graft, resulting in improved quadriceps strength (Fukuda et al., 2013). Further studies should assess the frequency and magnitude of quadriceps activation allowed.

OKC exercises to strengthen quadriceps are allowed for HT at 4-weeks but is limited to 90-45° as it places stress on the graft, while CKC places less stress on the graft.

11. Neuromuscular training (NMT)

NMT is the facilitation of movement training progressions from single plane low intensity training to multi-planar complex power training, resulting in improved joint kinaesthesia, stability, acceleration and deceleration (Hewett et al., 2002). In addition, NMT reduces ACL re-injury (Johansson et al., 1991) and includes balance, proprioception and plyometrics.
A combination of NMT and strengthening produce better outcomes than only strength training exercises after 6 months (Risberg et al., 2007) and also confirmed during 2 and 4 year follow-ups (Risberg & Holm 2009). NMT improved global knee function and pain relief, while strengthening improved hamstring strength after two years post-operative.

Rehabilitation should combine NMT and strength training to increase knee stability and movement coordination during supervised physiotherapy.

12. Neuromuscular Electrical stimulation (NMES)

Postoperative quadriceps inhibition is caused by arthrogenic muscle inhibition (Palmieri et al., 2004).
Combining NMES and quadriceps exercises improves quadriceps contraction during the first 4 weeks post-operative (Kim et al., 2010).
NMES is not a substitute for muscle volitional exercises (Bax et al., 2005), but will promote quadriceps contraction initially.
NMES compared to a standard post-operative strength programme improved the quadriceps strength of the NMES group by an average of 29% after 6-month follow-up (Feil et al., 2011). Inconclusive evidence exists to show whether NMES has any effect on functional performance or patient-orientated outcomes.

NMES may contribute to quadriceps contraction in the first weeks postoperatively, but patient-orientated outcomes may not be influenced.

13. Knee Bracing

Post-surgical bracing (0-6 weeks) has no beneficial influence on ACLR outcome, pain or knee stability (Wright et al., 2008a, Andersson et al., 2009).
No evidence was found that functional bracing reduces re-injury in 100 patients during land-based exercise (McDevitt et al., 2004).
However, functional knee bracing may enhance the proprioceptive input during downhill ski (Nemeth et al., 1997). Functional bracing showed reduced ACL re-injury during 6 seasons. The non-braced skiers were 3.9 times more likely to re-injure than the braced skiers (Sterett et al., 2006).

Post-operative bracing has no role in ACLR. Functional bracing may be effective in downhill skiing.

14. Home–based rehabilitation versus supervised rehabilitation

The quality and cost of rehabilitation protocols are influenced by home-based versus supervised rehabilitation.
Evidence showed no difference between home- and clinic-based groups assessed by knee ROM, laxity, strength and function (six months to one year) (Andersson et al., 2009).

A combined supervised- and home-programme will be more beneficial and cost effective during rehabilitation.

15. ACL Injury prevention and performance enhancing

Avoidance of knee compression, hip abduction torque and tibial internal rotation is essential for ski prevention programmes. By strengthening the hip abductor, extensor and hamstrings may contribute to protecting the knee against forces (Bere et al., 2014).
Injuries may be reduced by NMT, educational tools and interventions (Gagnier et al., 2013). Awareness videos and training programmes reduce injuries in professional skiers (Ettlinger et al., 1995). These videos prevented injuries by teaching skiers to identify and respond correctly when at risk of sustaining injury.
NMT should be implemented during the training of young female adolescents. This will counteract the neuromuscular deficiencies that develop at a later adolescent developmental phase, resulting in altered mechanics and injuries (Myer et al., 2013).
Injury prevention is effective (Walden et al., 2012). Injury reduction of 64% was achieved (N=4564, between ages of 12-17). Injuries occurred at -0.07 (95% CI -0.13 to 0.001) per 1,000 playing hours in favour of the preventative group (Walden, 2012).
A preventative programme must be encouraged by all MDT members. The programme must have a duration of 10 to 20 minutes, thrice weekly during pre-season and once weekly during season (Grindstaff et al., 2006).
Inconclusive evidence for the effectiveness and type of male injury prevention programmes exist (Alentorn-Geli et al., 2014).
Numbers-needed-to-treat is between 108-120 training players to prevent one ACL injury (Sugimoto et al., 2012a). Further research to improve the screening process together with sport specific prophylactic programmes are required.
The correct ski binding should be used for the level of skier and be adjusted properly to reduce ACL injuries (Young et al., 1976).

Effective prevention programmes need to be sport specific. Preventative videos are effective to educate skiers.

References

• Ajuied, A., Wong, F., Smith, C., Norris, M., Earnshaw, P., Back, D., & Davies, A. (2013). Anterior cruciate ligament injury and radiologic progression of knee osteoarthritis: a systematic review and meta-analysis. American Journal of Sports Medicine, DOI: 10.1177/0363546513508376.
• Alentorn-Geli, E., Mendiguchia, J., Samuelsson, K., Musahl, V., Karlsson, J., Cugat, R., & Myer, G.D. (2013). Prevention of non-contact anterior cruciate ligament injuries in sports. Part II: systematic review of the effectiveness of prevention programmes in male athletes. Knee Surgery, Sports Traumatology, Arthroscopy, 22(1): 16-25. DOI: 10.1007/s00167-013-2739-x.
• Amin, S., Guermazi, A., Lavalley, M.P., Niu, J., Clancy, M., Hunter, D.J., Grigoryan, M., & Felson, D.T. (2008). Complete anterior cruciate ligament tear and the risk for cartilage loss and progression of symptoms in men and women with knee osteoarthritis. Osteoarthritis Cartilage, 16(8): 897-902.
• Andernord, D., Karlsson, J., Musahl, V., Bhandari, M., Fu, F.H., Samuelsson, K. (2013). Timing of surgery of the anterior cruciate ligament. Arthroscopy, 29(11): 1863-1871. DOI: 10.1016/j.arthro.2013.07.270
• Andersson, D., Samuelsson, K., & Karlsson, J. (2009). Treatment of anterior cruciate ligament injuries with special reference to surgical technique and rehabilitation: an assessment of randomized controlled trials. Arthroscopy, 25(6): 653–685.
• Anderson, A.F., Snyder, R.B., Lipscomb, A.B. (2001). Anterior cruciate ligament reconstruction. A prospective randomised study of three surgical methods. American journal of Sports Medicine, 29(3): 272-279.
• Bax, L., Staes, F., & Verhagen, A. (2005). Does neuromuscular electrical stimulation strengthen the quadriceps femoris? A systematic review of randomised controlled trials. Sports Medicine, 35(3): 191-212.
• Bere, T., Flørenes, T.W., Nordsletten, L., & Bahr, R. (2014). Sex differences in the risk of injury in World Cup alpine skiers: a 6-year cohort study. British Journal of Sports Medicine, 48(1): 36-40. DOI: 10.1136/bjsports 2013-092206
• Beynnon, B.D., Johnson, R.J., Abate, J.A., Fleming, B.C., & Nichols, C.E. (2005). Treatment of anterior cruciate ligament injuries, Part I. The American Journal of Sports Medicine, 33(10): 1579– 1602. DOI: 10.1177/0363546505279913
• Beynnon, B.D., Johnson, R.J., Fleming, B.C., Stankewich, C.J., Renstrom, P.A., & Nichols, C.E. (1997). The strain behaviour of anterior cruciate ligament during squatting and active flexion-extension: a comparison of an open and closed kinetic chain exercise. American Journal of Sports Medicine, 25(6): 823-829.
• Beynnon, B.D., Johnson, R.J., Naud, S., Fleming, B.C., Abate, J.A., Brattbakk, B., Nichols, C.E. (2011). Accelerated versus nonaccelerated rehabilitation after anterior cruciate ligament reconstruction: a prospective, randomized, double-blind investigation evaluating knee joint laxity using roentgen stereophotogrammetric analysis. The American Journal of Sports Medicine, 39(12): 2536-2548. DOI: 10.1177/0363546511422349
• Birmingham, T.B., Bryant, D.M., Giffin, J.R., Litchfield, R.B., Kramer, J.F., Donner, A., & Fowler, P.J. (2008). A randomized controlled trial comparing the effectiveness of functional knee brace and neoprene sleeve use after anterior cruciate ligament reconstruction. The American Journal of Sports Medicine, 36(4): 648-655. DOI: 10.1177/0363546507311601
• Bjornsson, H., Desai, N., Musahl, V., Alentorn-Geli, E., Bhandari, M., Fu, F., & Samuelsson, K. (2013). Is double-bundle anterior cruciate ligament reconstruction superior to single-bundle? A comprehensive systematic review. Knee Surgery, Sports Traumatology, Arthroscopy. DOI: 10.1007/s00167-013-2666
• Böhm, H., & Senner, V. (2008). Effect of ski boot settings on tibio-femoral abduction and rotation during standing and simulated skiing. Journal of Biomechanics, 41(3): 498-505. DOI: 10.1016/j.jbiomech.2007.10.019
• Brophy, R.H., Wright, R.W., & Matava, M.J. (2009). Cost analysis of converting from single-bundle to double-bundle anterior cruciate ligament reconstruction. The American Journal of Sports Medicine, 37(4): 683-687. DOI: 10.1177/0363546508328121
• Busam, M.L., Provencher, M.T. & Back, B.R. (2008). Complications of anterior cruciate ligament reconstruction with bone-patellar tendon-bone constructs. Care and prevention. The American Journal of Sports Medicine, 36(2): 379-394. DOI: 10.1177/0363546507313498
• Button, K., van Deursen, R., & Price, P. (2006). Classification of functional recovery of anterior cruciate ligament copers, non-copers, and adapters. British Journal of Sports Medicine, 40(10): 853-85. DOI: 10.1136/bjsm.2006.028258
• Collins, N.J., Misra, D., Felson, D.J., Crossley, K.M., & Roos, E.M. (2011). Measures of knee function: International Knee Documentation Committee (IKDC) Subjective Knee Evaluation Form, Knee Injury and Osteoarthritis Outcome Score (KOOS), Knee Injury and Osteoarthritis Outcome Score Physical Function Short Form (KOOS-PS), Knee Outcome Survey Activities of Daily Living Scale (KOS-ADL), Lysholm Knee Scoring Scale, Oxford Knee Score (OKS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Activity Rating Scale (ARS), and Tegner Activity Score (TAS). Arthritis Care & Research. 63(S11): S208-S228. DOI: 10.1002/acr.20632
• Cosgarea, A.J., Sebastianielli, W.J., & DeHaven, K.E. (1995). Prevention of arthrofibrosis after ACL reconstruction using central third patellar tendon autograft. The American Journal of Sports Medicine, 23(1): 87-92.
• Ditmeyer, M.M., Topp, R., & Pifer, M. (2002). Prehabilitation in preparation of orthopaedic surgery. Orthopaedic Nursing, 21(5): 43-51.
• Ettlinger, C., Johnson, R., & Shealy J. (1995). A Method to help reduce the risk of serious knee sprains incurred in alpine skiing. The American Journal of Sports Medicine, 23(5): 531-537.
• Feil, S., Newell, J., Minogue, C., & Paessler, H.H. (2011). The effectiveness of supplementing a standard rehabilitation program with superimposed neuromuscular electrical stimulation after anterior cruciate ligament reconstruction: a prospective, randomized, single-blind study. The American Journal of Sports Medicine, 39(6): 1238-1247. DOI: 10.1177/0363546510396180
• Fitzgerald, G.K., Axe, M.J., & Snyder-Mackle, L. (2000). The efficacy of perturbation training in nonoperative anterior cruciate ligament rehabilitation programs for physically active individuals. Physical Therapy, 80(2): 128-140.
• Flørenes, T.W., Bere, T., Nordsletten, L., Heir, S., & Bahr, R. (2009). Injuries among male and female World Cup alpine skiers. British Journal of Sports Medicine, 43, 973–978. DOI: 10.1136/bjsm.2009.068759
• Fujimoto, E., Sumen, Y., Urabe, Y., Deie, M., Murakami, Y., Adachi N, & Ochi, M. (2004). An early return to vigorous activity may destabilize anterior cruciate ligaments reconstructed with hamstring grafts. Archives of Physical Medicine and Rehabilitation, 85(2): 298–302. DOI: 10.1016/S0003-9993(03)00621-X.
• Fukuda, T.Y., Fingerhut, D., Moreira, V.C., Camarini, P.M.F., Scodeller, N.F., Duarte, A., Martinelli, M., Bryk, F.F. (2013). Open kinetic chain exercises in a restricted range of motion after anterior cruciate ligament reconstruction: a randomized controlled clinical trial. The American Journal of Sports Medicine, 41(4): 788-794.
• Gagnier, J.J., Morgenstern, H., & Chess, L. (2013). Interventions designed to prevent anterior cruciate ligament injuries in adolescents and adults: a systematic review and meta-analysis. The American Journal of Sports Medicine, 41(8): 1952-1962. DOI: 10.1177/0363546512458227
• Garratt, A. M., Brealey, S., Gillespie, W. J., & DAMASK Trial Team (2004). Patient-assessed health instruments for the knee: a structured review. Rheumatology (Oxford, England), 43(11): 1414-1423. DOI: 10.1093/rheumatology/keh362
• Gokeler, A., Bisschop, M., Benjaminse, A., Myer, G.D., Eppinga, P., & Otten, E. (2013). Quadriceps function following ACL reconstruction and rehabilitation: implications for optimisation of current practices. Knee Surgery, Sports Traumatology, Arthroscopy. DOI: 10.1007/s00167-013-2577-x
• Grant, J.A. (2012). Does Accelerated Rehabilitation affect knee joint laxity after ACL reconstruction? Clinical Journal of Sport Medicine, 22(6): 523-524. DOI: 10.1097/JSM.0b013e318275d4f2
• Grant, J.A., Mohtadi, N.G. (2010). Two- to 4-year follow-up to a comparison of home versus physical therapy-supervised rehabilitation programs after anterior cruciate ligament reconstruction. The American Journal of Sports Medicine, 38(7): 1389-1394. DOI: 10.1177/0363546509359763
• Grant, J.A., Tannenbaum, E., Miller, B.S., & Bedi, A. (2012). Treatment of combined complete tears of the anterior cruciate and medial collateral ligaments. Arthroscopy, 28(1): 110-122. DOI: 10.1016/j.arthro.2011.08.293
• Griffin, L.Y., Albohm, M.J., Arendt, E.A., Bahr, R., Beynnon, B.D., Demaio, M., Dick, R.W., Engebretsen, L., Garrett, W.E., Hannafin, J.A., Hewett, T.E., Huston, L.J., Ireland, M.L., Johnson, R.J., Lephart, S., Mandelbaum, B.R., Mann, B.J., Marks, P.H., Marshall, S.W., Myklebust, G., Noyes, F.R., Powers, C., Shields, C., Shultz, S.J., Silvers, H., Slauterbeck, J., Taylor, D.C., Teitz, C.C., Wojtys, E.M., & Yu, B. (2006). Understanding and preventing noncontact anterior cruciate ligament injuries: a review of the Hunt Valley II meeting. The American Journal of Sports Medicine, 34(9): 1512–1532. DOI: 10.1177/0363546506286866
• Grindstaff, T.L., Hammill, R.R., Tuzson, A.E., & Hertel, J. (2006). Neuromuscular control training programs and noncontact anterior cruciate ligament injury rates in female athletes: a numbers-needed-to-treat analysis. Journal of Athletic Training, 41(4): 450-456.
• Guyatt, G.H., Sackett, D.L., Sinclair, J.C., Hayward, R., Cook, D.J., & Cook, R.J. (1995). Users’ guides to the medical literature IX. A method for grading health care recommendations. Evidence-Based Medicine Working Group. Journal of the American Medical Association, 274(22): 1800-1804.
• Hewett, T. E., Ford, K.R., & Myer, G.D. (2006). Anterior cruciate ligament injuries in female athletes – part 2: a meta-analysis of neuromuscular interventions aimed at injury prevention. The American Journal of Sports Medicine, 34(3): 490-498. DOI: 10.1177/0363546505282619
• Hewett, T.E., Paterno, M.V., & Myer, G.D. (2002). Strategies for enhancing proprioception and neuromuscular control of the knee. Clinical Orthopaedics and Related Research, 402, 76-94.
• Hurd, W.J., Axe, M.J., Snyder-Mackler, L. (2008). A 10-year prospective trial of a patient management algorithm and screening examination for highly active individuals with anterior cruciate ligament injury: Part 2, determinants of dynamic knee stability. The American Journal of Sports Medicine, 36(1): 48-56. DOI: 10.1177/0363546507308191
• Irrgang, J.J., Anderson, A.F., Boland, A.L., Harner, C.D., Neyret, P., Richmond, J.C., Shelbourne, K.D. (2006). Responsiveness of the International Knee Documentation Committee Subjective Knee Form. The American Journal of Sports Medicine, 34: 1567-1573. DOI: 10.1177/0363546506288855
• Irrgang, J.J., Snyder-Mackler, L., Wainner, R.S., Fu, F.H., & Harner, C.D. (1998). Development of a patient-reported measure of function of the knee. Journal of Bone and Joint Surgery [American Volume], 80(8): 1132–1145.
• Johansson, H., Sjolander, P., & Sojka, P. (1991). A sensory role for the cruciate ligaments. Clinical Orthopaedics & Related Research, 268, 161-178.
• Johnson, S.C. (1995). Anterior cruciate ligament injury in elite Alpine competitors. Medicine and Science in Sports and Exercise, 27(3): 323–327.
• Kongtharvonskul, J., Attia, J., Thamakaison, S., Kijkunasathian, C., Woratanarat, P., & Thakkinstian, A. (2013). Clinical outcomes of double- vs single-bundle anterior cruciate ligament reconstruction: a systematic review of randomized control trials. Scandinavian Journal of Medicine and Science in Sports, 23(1): 1-14. DOI: 10.1111/j.1600-0838.2011.01439.x
• Kim, K.M., Croy, T., Hertel, J., & Saliba, S. (2010). Effects of neuromuscular electrical stimulation after anterior cruciate ligament reconstruction on quadriceps strength, function, and patient-oriented outcomes: a systematic review. Journal of Orthopaedic and Sports Physical Therapy, 40(7): 383-391. DOI: 10.2519/jospt.2010.3184
• Klein, W., & Jensen, K.U. (1992). Synovites and artificial ligaments. Arthroscopy, 8(1): 116-124.
• Kokmeyer, D., Wahoff, M., & Mymern, M. (2012). Suggestions from the field for return-to-sport rehabilitation following Anterior Cruciate Ligament Reconstruction: Alpine Skiing. Journal of Orthopaedic and Sports Physical Therapy, 42(4): 313-325. DOI: 10.2519/jospt.2012.4024
• Kruse, L.M., Gray, B., & Wright, R.W. (2012). Rehabilitation after anterior cruciate ligament reconstruction: a systematic review. Journal of Bone and Joint Surgery [American Volume], 94(19): 1737-174. DOI: 10.2106/JBJS.K.01246
• Kwok, C.S., Harrison, T., & Servant, C. (2013). The optimal timing for anterior cruciate ligament reconstruction with respect to the risk of postoperative stiffness. Arthroscopy, 29(3): 556-565. DOI: 10.1016/j.arthro.2012.09.005
• Lamblin, C.J., Waterman, B.R., & Lubowitz, J.H. (2013). Anterior cruciate ligament reconstruction with autografts compared with non-irradiated, non-chemically treated allografts. Arthroscopy, 29(6): 1113-1122. DOI: 10.1016/j.arthro.2013.01.022
• Li, Y.L., Ning, G.Z., Wu, Q., Wu, Q.L., Li, Y., Hao, Y., & Feng, S.Q. (2014). Single-bundle or double-bundle for anterior cruciate ligament reconstruction: a meta-analysis. The Knee, 21(1): 28-37. DOI: 10.1016/j.knee.2012.12.004
• Liden, M., Ejerhed, L., Sernert, N., Laxdal, G., & Kartus, J. (2007). Patellar tendon or semitendinosus tendon autografts for anterior cruciate ligament reconstruction: a prospective, randomized study with a 7-year follow-up. The American Journal of Sports Medicine, 35(5): 740-748. DOI: 10.1177/0363546506298275
• Linko, E., Harilainen, A., Malmivaara, A., & Seitsalo, S. (2005). Surgical versus conservative interventions for anterior cruciate ligament ruptures in adults. Cochrane Database of Systematic Reviews, Issue 2, Art. No.: CD001356. DOI: 10.1002/14651858.CD001356.pub3
• Logerstedt, D.S., Snyder-Mackler, L., Ritter, R.C., Axe, M.J., Godges, J.J. (2010a). Knee stability and movement coordination impairments: knee ligament sprain. Journal of Orthopaedic and Sports Physical Therapy, 40(4): A1-A37. DOI: 10.2519/jospt.2010.0303
• Logerstedt, D.S., Snyder-Mackler, L., Ritter, R.C., Axe, M.J. (2010b). Knee pain and mobility impairments: meniscal and articular cartilage lesions. Journal of Orthopaedic and Sports Physical Therapy, 40(6): A1-A35. DOI: 10.2519/jospt.2010.0304
• Lubowitz, J.H., & Appleby, D. (2011). Cost-effectiveness analysis of the most common orthopaedic surgery procedures: knee arthroscopy and knee anterior cruciate ligament reconstruction. Arthroscopy, 27(10): 1317-1322. DOI: 10.1016/j.arthro.2011.06.001
• Lyman, S., Koulouvaris, P., Sherman, S., Do, H., Mandl, L.A., Marx, R.G. (2009). Epidemiology of anterior cruciate ligament reconstruction: trends, readmissions, and subsequent knee surgery. Journal of Bone and Joint Surgery [American Volume], 91(10): 2321-2328. DOI: 10.2106/JBJS.H.00539
• Lysholm, J., & Gillquist, J. (1982). Evaluation of the knee ligament surgery results with special emphasis on use of a scoring scale. The American Journal of Sports Medicine, 10(3): 150-154.
• MacDonald, P.B., Hedden, D., Pacin, O., & Huebert, D. (1995). Effects of an accelerated rehabilitation program after anterior cruciate ligament reconstruction with combined semitendinosus-gracilis autograft and a ligament augmentation device. The American Journal of Sports Medicine, 23(5): 588–592. DOI: 10.1177/036354659502300512.
• Magnussen, R.A., Carey, J.L., & Spindler, K.P. (2011). Does autograft choice determine intermediate-term outcome of ACL reconstruction? Knee Surgery, Sports Traumatology, Arthroscopy, 19(3): 462-472. DPO: 10.1007/s00167-010-1277-z
• Magnussen, R.A., Granan, L.P., Dunn, W.R., (2010). Cross-cultural comparison of patients undergoing ACL reconstruction in the United States and Norway. Knee Surgery, Sports Traumatology, Arthroscopy, 18(1): 98 105. DOI: 10.1007/s00167-009-0919-5
• Magnussen, R.A., Lawrence, J.T., West, R.L., Toth, A.P., Taylor, D.C., & Garrett, W.E., (2012). Graft size and patient age are predictors of early revision after anterior cruciate ligament reconstruction with hamstring autograft. Arthroscopy, 28(4): 526-531. DOI: 10.1016/j.arthro.2011.11.024
• Maletis, G.B., Cameron, S.L., Tengan, J.J., & Burchette, R.J. (2007). A prospective randomized study of anterior cruciate ligament reconstruction: a comparison of patellar tendon and quadruple-strand semitendinosus/gracilis tendons fixed with bioabsorbable interference screws. The American Journal of Sports Medicine, 35(3): 384-394.
• Maletis, G.B., Inacio, M.C., Desmond, J.L., & Funahashi, T.T. (2013a). Reconstruction of the anterior cruciate ligament association of graft choice with increased risk of early revision. Bone and Joint Journal, 95(5): 623 628. DOI: 10.1302/0301-620X.95B5.30872
• Maletis, G.B., Inacion, M.C., Reynolds, S., Desmond, J.L., Maletis, M.M., & Funahashi, T.T. (2013b). Incidence of postoperative anterior cruciate ligament reconstruction infections: graft choice makes a difference. The American Journal of Sports Medicine, 41(8): 1780-1785. DOI: 10.1177/0363546513490665
• Mather, R.C., Koenig, L., Kocher, M.S., Dall, T.M., Gallo, P., Scott, D.J., Bach, B.R.J., Spindler, K.P., & MOON Knee Group (2013). Societal and economic impact of anterior cruciate ligament tears. Journal of Bone and Joint Surgery [American Volume], 95(19): 1751-1759. DOI: 10.2106/JBJS.L.01705
• Mauro, C.S., Irrgang, J.J., Williams, B.A., Harner, C.D. (2008). Loss of extension following anterior cruciate ligament reconstruction: analysis of incidence and etiology using IKDC criteria. Arthroscopy, 24(2): 146 153. DOI: 10.1016/j.arthro.2007.08.026
• McDevitt, E.R., Taylor, D.C., Miller, M.D., Gerber, J.P., Ziemke, G., Hinkin, D., Uhorchak, J.M., Arciero, R.A., & Pierre, P.S. (2004). Functional bracing after anterior cruciate ligament reconstruction: a prospective, randomized, multicenter study. The American Journal of Sports Medicine, 32(8): 1887-1892.
• Mohtadi, N.G., Chan, D.S., Dainty, K.N., & Whelan, D.B. (2011). Patellar tendon versus hamstring tendon autograft for anterior cruciate ligament rupture in adults. Cochrane Database of Systematic Reviews, Issue 9, Art. No.: CD005960. DOI: 10.1002/14651858.CD005960.pub2
• Myer, G.D., Schmitt, L.C., Brent, J.L., Ford, K.R., Foss, K.D.B., Scherer, B.J., Heidt, R.S., Divine, J.G., & Hewett, T.E. (2011). Utilization of modified NFL combine testing to identify functional deficits in athletes following ACL reconstruction. Journal of Orthopaedic and Sports Physical Therapy, 41(6): 377-387. DOI: 10.2519/jospt.2011.3547
• Myer, G.D., Sugimoto, D., Thomas S., & Hewett T. (2013). The influence of age on the effectiveness of neuromuscular training to reduce anterior cruciate ligament injury in female athletes – A meta-analysis. The American Journal of Sports Medicine, 41(1): 203-215. DOI: 10.1177/0363546512460637
• Mulford, J.S., & Chen, D. (2011). Anterior cruciate ligament reconstruction: A systematic review of polyethylene terephthalate grafts. ANZ Journal of Surgery, 81(11): 785-789.
• Natri, A., Beynnon, B.D., Ettlinger, C.F., Johnson, R.J., & Shealy, J.E. (1999). Alpine ski bindings and injuries. Current findings. Sports Medicine (Auckland, N.Z.), 28(1): 35-48.
• Nemeth, G., Lamontagne, M., Tho, K., Eriksson, E. (1997). Electromyographic activity in expert downhill skiers using functional knee braces after anterior cruciate ligament injuries. The American Journal of Sports Medicine, 25(5): 635-664.
• Negus, J., Fransen, M., Chen, J.S., Parker, D.A, March, L. (2012). Exercise-based interventions for conservatively or surgically treated anterior cruciate ligament injuries in adults. Cochrane Database of Systematic Reviews, Issue 10, Art. No.: CD010128. DOI: 10.1002/14651858.CD010128
• Noyes, F.R., Barber, S.D., & Mangine, R.E. (1991). Abnormal lower limb symmetry determined by function hop tests after anterior cruciate ligament rupture. American Journal of Sports Medicine, 19(5): 513–518.
• Pan, X., Wen, H., Wang, L., & Ge, T., (2013). Bone–patellar tendon–bone autograft versus LARS artificial ligament for anterior cruciate ligament reconstruction. European Journal of Orthopaedic Surgery and Traumatology, 23(7): 819-823. DOI: 10.1007/s00590-012-1073-1.
• Papageorgiou, C.D., Ma, C.B., Abramowitch, S.D., Clineff, T.D., & Woo, S.L. (2001). A multidisciplinary study of the healing of an intraarticular anterior cruciate ligament graft in a goat model. The American Journal of Sports Medicine, 29(5): 620-626.
• Palmieri, R.M., Tom, J.A., Edwards, J.E., Weltman, A., Saliba, E.N., Mistry, D.J., & Ingersoll, C.D. (2004) Arthrogenic muscle response induced by an experimental knee joint effusion is mediated by pre- and post-synaptic spinal mechanisms. Journal of Electromyography and Kinesiology, 14(6): 631–640.
• Paxton, E.S., Kymes, S.M., & Brophy, R.H. (2010). Cost-effectiveness of anterior cruciate ligament reconstruction: a preliminary comparison of single-bundle and double-bundle techniques. The American Journal of Sports Medicine, 38(12): 2417-2425. DOI: 10.1177/0363546510375545
• Persson, A., Fjeldsgaard, K., Gjertsen, J.E., Kjellsen, A.B., Engelbretsen, L., Hole, R.M., & Fevang, J.M. (2014). Increased Risk of revision with hamstring tendon grafts compared with patellar tendon grafts after anterior cruciate ligament reconstruction. American Journal of Sports Medicine, 42(2): 258-291.
• Pichon, R.A., Augustovski, F., Alcaraz, A., Bardach, A., Ferrante, D., Garcia, M.S., Glujovsky, D., Lopez, A., Regueiro, A. (2007). Usefulness of synthetic graft in knee anterior cruciate ligament reconstruction. Buenos Aires: Institute for Clinical Effectiveness and Health Policy (IECS). Informe de Respuesta Rapida, 91.
• Pujol, N., Blanchi, M.P., & Chambat, P. (2007). The incidence of anterior cruciate ligament injuries among competitive Alpine skiers: a 25-year investigation. The American Journal of Sports Medicine, 35(7): 1070-1074.
• Rahr-Wagner, L., Thillemann, T.M., & Pedersen, A.B. (2014). Comparison of Hamstring Tendon and Patellar Tendon Grafts in Anterior Cruciate Ligament Reconstruction in a Nationwide Population-Based Cohort Study: Results from the Danish Registry of Knee Ligament Reconstruction. American Journal of Sports Medicine, 42(2): 278-284.
• Ramski, D.E., Kanj, W.W., Franklin, C.C., Baldwin, K.D., & Ganley, T.J. (2013). Anterior cruciate ligament tears in children and adolescents: a meta-analysis of nonoperative versus operative treatment. The American Journal of Sports Medicine. DOI: 10.1177/0363546513510889
• Ramos, J., Perrotta, C., Badariotti, G., & Berenstein, G. (2008). Interventions for preventing venous thromboembolism in adults undergoing knee arthroscopy. Cochrane Database of Systematic Reviews, Issue 4, Art. No.: CD005259. DOI: 10.1002/14651858.CD005259.pub3
• Raynor, M.C., Pietrobon, R., Guller, U., Higgins, L.D. (2005). Cryotherapy after ACL reconstruction: a meta-analysis. The Journal of Knee surgery, 18(2): 123-129.
• Renstrom, P.A., (2013). Eight clinical conundrums relating to anterior cruciate ligament (ACL) injury in sport: Recent evidence and a personal reflection. British Journal of Sports Medicine, 47(6): 367-372. DOI: 10.1136/bjsports-2012-091623
• Reid, A., Birmingham, T.B., Stratford, P.W., Alcock, G.K., & Giffin, J.R. (2007). Hop testing provides a reliable and valid outcome measure during rehabilitation after anterior cruciate ligament reconstruction. Physical Therapy, 87(3): 337–349. DOI: 10.2522/ptj.20060143
• Roos, E.M., Roos, H.P., & Lohmander, L.S., (1998). Knee Injury and Osteoarthritis Score (KOOS)- development of a self-administrated outcome measurement. Journal of Orthopaedic Sports Physical Therapy. 28(2): 88-96.
• Roos, E.M., Bremander, A.B., Englund, M., & Lohmander, L.S. (2008). Changes in self-reported outcomes and objective physical functions over 7 years in middle-aged subjects with or at high risk of knee osteoarthritis. Annals of Rheumatic Diseases, 67(4): 505-510.
• Risberg, M.A., Holm, I, Myklebust, G., & Engebretsen, L. (2007). Neuromuscular training versus strength training during first 6 months after anterior cruciate ligament reconstruction: a randomized clinical trial. Physical Therapy, 87(6): 737-750.
• Risberg, M.A., & Holm, I. (2009). The long-term effect of 2 postoperative rehabilitation programs after anterior cruciate ligament reconstruction: a randomized controlled clinical trial with 2 years of follow-up. The American Journal of Sports Medicine, 37(10): 1958-1966. DOI: 10.1177/0363546509335196
• Ross, M.D., Langford, B., & Whelan, P.J. (2002). Test-retest reliability of 4 single-leg horizontal hop tests. Journal of Strength and Conditioning Research, 16(4): 617-622.
• Scheffler, S.U., Unterhauser, F.N., & Weiler, A. (2008). Graft remodelling and ligamentization after cruciate ligament reconstruction. Knee Surgery, Sports Traumatology, Arthroscopy, 16(9): 834-842. DOI: 10.1007/s00167-008-0560-8
• Shaarani, S.R., O’Hare, C., Quinn, A., Moyna, N., Moran, R., & O’Byrne, J.M. (2013). Effect of prehabilitation on the outcome of anterior cruciate ligament reconstruction. The American Journal of Sports Medicine, 41(9): 2117-2127. DOI: 10.1177/0363546513493594
• Shelbourne, K.D., & Nitz, P. (1990). Accelerated rehabilitation after anterior cruciate ligament reconstruction. The American Journal of Sports Medicine, 18(3): 292-299.
• Sterett, W.I., Briggs, K.K., Farley, T., & Steadman, J.R. (2006). Effect of functional bracing on knee injury in skiers with anterior cruciate ligament reconstruction: a prospective cohort study. The American Journal of Sports Medicine, 34(10): 1581-1585. DOI: 10.1177/0363546506289883
• Sugimoto, D., Myer, G.D., McKeon, J.M., & Hewett, T.E. (2012a). Evaluation of the effectiveness of neuromuscular training to reduce anterior cruciate ligament injury in female athletes: a critical review of relative risk reduction and numbers-needed-to-treat analyses. British Journal of Sports Medicine, 46(14): 979 988. DOI: 10.1136/bjsports-2011-090895
• Sugimoto, D., Myer, G.D., Bush, H.M., Klugman, M.F., Medina McKeon, J.M., & Hewett, T.E. (2012b). Compliance with neuromuscular training and anterior cruciate ligament injury risk reduction in female athletes: a meta-analysis. Journal of Athletic Training, 47(6): 714-723. DOI: 10.4085/1062 6050-47.6.10.
• Tegner, Y., & Lysholm, J. (1985). Rating systems in the evaluation of knee ligament injuries. Clinical Orthopaedics and Related Research, 198, 43-49.
• Tiamklang, T., Sumanont, S., Foocharoen, T., Laopaiboon, M. (2012). Double-bundle versus single-bundle reconstruction for anterior cruciate ligament rupture in adults. Cochrane Database of Systematic Reviews, Issue 11. Art. No.: CD008413. DOI: 10.1002/14651858.CD008413.pub2
• Van Ginckel, A., Verdonk, P., & Witvrouw, E. (2013). Cartilage adaptation after anterior cruciate ligament injury and reconstruction: implications for clinical management and research? A systematic review of longitudinal MRI studies. Osteoarthritis and Cartilage, 21(8): 1009-1024. DOI: 10.1016/j.joca.2013.04.015
• Van Grinsven, S., Cingel, R.E.H., Holla, C.J.M., Van Loon, C.J.M. (2010). Evidence-Based rehabilitation following anterior cruciate ligament reconstruction. Knee Surgery, Sports Traumatology, Arthroscopy, 18(8): 1128-1144. DOI: 10.1007/s00167-009-1027-2
• Van Tongel, A., Stuyck, J., Bellemans, J., & Vandenneucker, H. (2007). Septic arthritis after arthroscopic anterior cruciate ligament reconstruction: a retrospective analysis of incidence, management and outcome. The American Journal of Sports Medicine, 35(7): 1059-1063. DOI: 10.1177/0363546507299443
• Walden, M., Atroshi I, Magnusson H, Wagner P, Hagglund M., (2012). Prevention of acute knee injuries in adolescent female football players: cluster randomised controlled trial. British Medical Journal, 344:e3042. DOI: 10.1136/bmj.e3042
• Webster, K.E., Feller, J.A., & Hameister, K.A. (2001). Bone tunnel enlargement following anterior cruciate ligament reconstruction: a Randomised comparison of hamstring and patellar tendon grafts with 2 year follow-up. Knee Surgery, Sports Traumatology, Arthroscopy, 9(2): 86-91.
• Weiler, A., Hiffman, R.F.G., Rehm, O., & Südkamp, N.P. (2002). Tendon Healing in a bone tunnel part 11: Histologic analysis after biodegradable interference fit fixation in a model of anterior cruciate ligament reconstruction in sheep. Arthroscopy, 18(2): 124-135.
• Westin, M., Alricsson, M., & Werner, S. (2012). Injury profile of competitive alpine skiers: a five-year cohort study. Knee Surgery, Sports Traumatology and Arthroscopy, 20(6): 1175-1181. DOI: 10.1007/s00167 012 1912 x
• Wright, R.W., Preston, E., Fleming, B.C., Amendola, A., Andrish, J.T., Bergfeld, J.A., Dunn, W.R., Kaeding, C., Kuhn, J.E., Marx, R.G., McCarty, E.C., Parker, R.C., Spindler, K.P., Wolcott, M., Wolf, B.R., Williams, G.N. (2008a). A systematic review of anterior cruciate ligament reconstruction rehabilitation: part I: continuous passive motion, early weight bearing, postoperative bracing, and homebased rehabilitation. The Journal of Knee Surgery, 21(3): 217-224.
• Wright, R.W., Preston, E., Fleming, B.C., Amendola, A., Andrish, J.T., Bergfeld, J.A., Dunn, W.R., Kaeding, C., Kuhn, J.E., Marx, R.G., McCarty, E.C., Parker, R.C., Spindler, K.P., Wolcott, M., Wolf, B.R., Williams, G.N. (2008b). A systematic review of anterior cruciate ligament reconstruction rehabilitation: part II: open versus closed kinetic chain exercises, neuromuscular electrical stimulation, accelerated rehabilitation, and miscellaneous topics. The Journal of Knee Surgery, 21(3): 225-234.
• Wright, R.W. (2009). Knee injury outcomes measures. Journal of the American Academy of Orthopaedic Surgeons, 17(1): 31-39.
• Xu, M., Gao, S., Zeng, C., Han, R., Sun, J., Li, H., Xiong, Y., Lei, G. (2013). Outcomes of anterior cruciate ligament reconstruction using single-bundle versus double-bundle technique: meta-analysis of 19 randomized controlled trials. Arthroscopy, 29(2): 357-365. DOI: 10.1016/j.arthro.2012.08.024
• Yoo, J.H., Lim, B.O., Ha, M., Lee, S.W., Oh, S.J., Lee, Y.S., & Kim, J.G. (2010). A meta-analysis of the effect of neuromuscular training on the prevention of the anterior cruciate ligament injury in female athletes. Knee Surgery, Sports Traumatology, Arthroscopy, 18(6): 824-830.
• Young, R., Aronsson, D., Johnson, R., Ettlinger, C., Shealy, J., (1976). The etiology of ski injuries: An eight year study of the skier and his equipment. The Orthopaedic clinics of North America, 7(1): 13-29.
• Zätterström, R., Fridén, T., Lindstrand, A., Moritz, U. (2000). Rehabilitation following acute anterior cruciate ligament injuries–a 12-month follow-up of a randomized clinical trial. Scandinavian Journal of Medicine and Science in Sports, 10(3): 156-163.
• Zhu, Y., Tang, R.K., Zhao, P., Zhu, S.S., Li, Y.G., Li, J.B. (2013). Double-bundle reconstruction results in superior clinical outcome than single-bundle reconstruction. Knee Surgery, Sports Traumatology, Arthroscopy, 21(5): 1085-1096. DOI: 10.1007/s00167-012-2073-8
• National Guideline Clearinghouse (NGC) (https://www.guideline.gov/). Accessed 16/2/2014.
• Centre of Evidence based medicine Oxford United Kingdom (http://www.cebm.net) Accessed 16/2/2014.

Disclaimer

The contents of this article – Management of ACL Ruptures in Skiers, is aimed at medical professionals. It is provided here for informational purposes only and should not be treated as medical or health management advice. The materials herein are not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your doctor, physiotherapist or other health care provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read in this article or website. Reliance on any information provided herein is solely at your own risk.

Copyright

The content of this article – Management of ACL Ruptures in Skiers, is copyright © 2016 of Suegnet Meyer and Meyer & Associates. Transmission or reproduction of the contents, beyond that allowed by fair use as defined in the copyright laws requires the written permission of the copyright owners.

The post Management of ACL Ruptures in Skiers first appeared on Meyer Physio.

PFPS vs Pain

Hodges et al (2009) induced pain by injecting fat pads which did cause delayed VMO. With the increasing or aggravating the pain caused decrease in VM muscle activation. Furthermore swelling can also cause reduced VMO activity. Stokes et al., (1984) injected 10ml of fluid causing VM to inhibited while VL was inhibited only after injecting 40ml fluid. Swelling and Pain will inhibit VMO activation according to these studies and be a contributing factor to PFPS.

Influence of the hip & foot on PFPS?

In addition to my previous answer last week, weakness of the hip abductors and external rotators can cause PFPS as demonstrated by Souza & Powers (2009). Increased hip internal rotation ROM with weakness of hip abductor muscles were observed in females suffering from PFPS (in weight bearing). Powers (2003) also previously documented that since the patella is influenced by the interaction of proximal and distal segments that abnormal tibia and femur motion in the transverse and frontal planes have an effect on the PFJ. This highlights the importance of stability of the hip (strength training of hip abductors and external rotators) and the foot. This will also have a better long term effect and prevent further injury.

Rehabilitation of the VM / VMO to Optimise Patello-Femoral mechanics

Beside taking the hip Abductor strength and feet biomechanical factors as well as muscle lengths of gastrocs/soleus/hamstrings in consideration, rehab in closed chain kinematics :

Method

To make sure that the VMO is optimally rehabilitated, firstly educate the patient how to static contract the VM (pain free) by locating and palpating the VM or using EMG feedback. By using PF tape or ice brushing can facilitate VM contraction. The patient needs to train VM contraction regularly during the day. Since optimum contraction will be in a closed chain, persue weight bearing position but in a pain free ROM. By watching out for signs of fatigue, posture positioning of the foot and hip, and preferrebly in closed chain, get the patient to do this frequently during the day to promote the neuro-muscular pattern and try to facilitate the VM contraction and endurance. Progresssion for endurance and strength in larger range of motion can be achieved by using terminal extension with theraband. Assess what ROM gives them pain during function (stairs) and break the components down and strengthen the knee/hip in that spesific range but still be aware of pain as a contraindication and keep icing to reduce pain and inflammation. Taping may also help. Use a raised chair height or perhaps the side of a desk and let them train, controlling the VM while getting up from this elevated position instead of working through a full range of motion, causing pain that they are unable to tolerate anyway. If this is tollerated, progress mini squats supported to single leg squats with support, then without support, but ensuring no pain with good hip foot knee control and posture. Progressive weight training can then be introduced and sport specific exercises.

References

1. Bolgla, L. A., Malone, T.R. Umberger B.R., (2011). Comparison of hip and knee strength and neuromuscular activity in subjects with and without patella femoral pain syndrome. The International Journal of Sports Physical Therapy. 6(4) : 285-296.
2. Cagnie B, Elliott JM, O’Leary S, D’hooge R, Dickx N, Danneels LA (2011). Muscle functional MRI as an imaging tool to evaluate muscle activity. Journal of Orthopaedic & Sports Physical Therapy; 41 (11): 896–903.
3. Hodges PW., Mellor R., Crossley K., Bennell K. (2009). Pain induce by injecting hypertonic saline into the infra patellar fat pad an effect on coordination of the quadriceps muscle. Arthritir Rheum 61); 70-77.
4. O’Leary S, Cagnie B, Reeve A, Jull G, Elliott JM (2011). Is there altered activity of the extensor muscles in chronic mechanical neck pain? A functional magnetic resonance imaging study. Arch Phys Med Rehabil. 2011; 92 (6): 929–34.
5. Pattyn, E., Verdonker, P., Adelheid. S., Van Tiggelen, D., (2013). Muscle functional MRI to evaluate quadriceps dysfunction in patella femoral pain. Medicine and science in sports and exercise: 45 (6) 1023-1030.
6. Powers, CM., (2003). The influence of altered lower extremity kinematics on patellofemoral joint dysfunction : a theoretical perspective. Journal of Orthopaedic Sports Physical Therapy. 33(11):639-646.
7. Souza RB, Powers CM. (2009). Differences in hip kinematics, muscle strength and muscle activation between subjects with and without patella femoral pain. Journal of Orthopaedic Sports Physical Therapy 39(1) 12-19.
8. Stokes M., Young A., (1984). The contribution of reflex inhibition to arthrogenous muscle weakness. Clinical Science. 67: 7-14.

Disclaimer

The contents of this article – Quadriceps Dysfunction in Patello Femoral Pain Syndrome, is aimed at Physiotherapists and other medical professionals. It is provided here for informational purposes only and should not be treated as medical or health management advice. The materials herein are not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your doctor, physiotherapist or other health care provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read in this article or website. Reliance on any information provided herein is solely at your own risk.

Copyright

The content of this article – Quadriceps Dysfunction in Patello Femoral Pain Syndrome, is copyright © 2016 of Suegnet Meyer and Meyer & Associates. Transmission or reproduction of the contents, beyond that allowed by fair use as defined in the copyright laws requires the written permission of the copyright owners.

The post Quadriceps Dysfunction in Patello Femoral Pain Syndrome first appeared on Meyer Physio.

Introduction

This literature review looks at Cervical Injuries that occur during participation in sport. It looks at injuries that happen in sport with frequent impact, e.g. Rugby and American Football, and also injuries due to continuous strain induced by high G-forces, e.g. Motorsport, Bobsleigh and Skeleton.

Aims

The aims of this literature review are to establish: 1) Which muscles stabilise the neck? 2) Which Cervical Strengthening (CS) exercises are most effective? 3) Whether cervical strengthening is effective for rehabilitation and injury prevention?

Method

For this study, literature from 1990 to October 2013 found via the databases of Google Scholar, Pedro, Pubmed, SportsDiscus and Web of Knowledge, using keyword examples ‘cervical injury’, ’stinger’ ,’g-force’ and ‘neck strengthening’, was reviewed. Furthermore, mainly high quality original studies as well as studies identified from the reference lists were used. ‘Grey literature’ (e.g. reputable websites, online discussions and dissertations) were included.

Spine Injuries in Rugby and American Football

Serious cervical injuries were reduced, since rule modifications in high collision sport of Rugby and Football. Unfortunately minor traumatic cervical injuries still occur. Tackling is a major injury cause, especially during match-play and makes up 34-56% of all rugby injuries (Brooks et al., 2005; McIntosh et al., 2010). The American National Football League reported during 1997 to 2006, 300 players were injured with 350 games missed due to neural traction injuries (Qureshi & Hecht, 2010). Minor injuries, e.g. neural traction injuries, transient brachial plexopathy or ‘stingers’, occur frequently during tackling (Weinberg, 2003). The injury mechanism is uncertain. It is suggested that: a brachial plexus traction injury occurs when the neck is forced into lateral flexion together with shoulder depression (Clancy et al., 1977); or off-centre axial force causing cervical nerve root compression during cervical hyperextension and ipsilateral lateral flexion trauma (Watkins 1986, Levitz et al., 1997); or a direct supraclavicular blow resulting in a brachial plexus compression injury (Di Benedetto & Markey 1984). The frequent minor compression injuries during tackling cause cervical sprain injuries, inflammation and secondary degeneration (Meyer et al., 1994), which can result in cervical stenosis (Torg et al., 1986) and may cause altered cervical spine mechanics (Levitz et al., 1997).

Spine Injuries in Motorsport, Bobsleigh and Skeleton

Cervical spines of racing drivers and bob-skeleton athletes are affected by gravity force (g-force) related stressors causing axial force, vibration, mechanical shock, whiplash injuries and concussion (Mansfield & Marshall, 2001; Minoyama & Tsuchida, 2004; Engebretsen et al., 2010). These forces cause sheering, buckling and strain on the cervical region together with accidents that may have impact of more than 25G’s (http://www.bbc.co.uk/sport/0/formula1/24976578). A study of single seated car races found 1.2 injuries per 1000 competitors per race and 0.9 injuries per 1000 competitors per single saloon car race. Saloon drivers suffered 53.2% cervical sprain injuries (Minoyama & Tsuchida (2004).
The bob-skeleton is a small sled without brakes. The athlete drops onto the sled in prone and reaches speeds of 120-135km/hr while g-forces can exceed 5G’s at various angulations including labyrinth track or hairpin bends. Helmets are the only head protection against high g-forces and accidents (http://www.olympic.org/skeleton). During the Winter Olympics 2010, 6% of Bob-skeleton athletes suffered cervical injuries and 5% suffered concussion (Engebretsen et al., 2010). Cervical injuries occur in collision and g-force related sports resulting in injury.
Strength training is suggested as rehabilitation and injury prevention in these sports. However the effectiveness of cervical strengthening (CS) is questionable.

1. The Cervical stabilisers:

The deep cervical flexors (DCF) and extensors (DCE) create a stabilising sleeve around the spine and become dysfunctional during cervical disorders (Falla et al., 2004c; O’Leary et al., 2013). If a specific stabilising muscle group is targeted and trained accurately, an increase muscle activity would cause directional stability and reduce the spinal neutral zone (Panjabi, 1992a & Panjabi, 1992b).
DCE
The DCE: Semispinalis cervicis, Multifidus, Rotatores muscles and the cranio-cervical extensors function as the dorsal inter-segmental neck stabilisers, producing extension and located close to the vertebrae. Multifidus consist of 77% Type I and 23% Type II fibre composition with small moment arms to create only capacity of 1Nm but fibre type can be transient to type II (Uhlig et al., 1995; Boyed-Clarke et al., 2002; Anderson et al., 2005). Due to changes on Cross-sectional area (CSA), DCE muscle dysfunction is implied in whiplash and cervical pain (Elliott et al., 2006; Elliott et al., 2008). In addition, reduced muscle activation has been shown on muscle functional MRI (mfMRI) (O’Leary et al., 2012). Future research in dynamic situation is required to assess muscle activation in various dynamic exercise via mfMRI.
Longus Colli & Capitis (DCF)
The DCF is a spinal stabiliser controlling the cervical lordosis and intervertebral motion (Mayoux-Benhamou et al., 1994). A CSA of Longus Colli demonstrated 53% type I and 47% type II fibre composition indicating a phasic as well as a postural function (Boyed-Clarke et al., 2001). The DCF fibres attach to the cervical vertebral laminae and maintain the cervical posture against gravity and have an antagonistic relationship with Multifidus (Mayoux-Benhamou et al., 1994). The superficial flexors Anterior Scaleni (AS) & Sternocleidomastoid (SCM) are unable to control the segmental motion and result in uncontrolled motion if no DCF activation occurs (Falla et al., 2007). The AS & SCM EMG measurements will increase due to over activity while the DCF will have reduced muscle activation. Fatigue sets in if overtraining occurs at low loading and is more apparent at 25% of the maximal voluntary contraction (MVC). When planning a training programme excessive loading and fatigue must be avoided to avoid since it will result in deactivation of the DCF (Falla et al., 2004e).
Initially, the DCF was described as one functional unit (Falla et al., 2004a; Falla et al., 2004d). Recently, it was confirmed by mfMRI that the DCF is activated during cranio-cervical flexion (CCF). It showed that Longus Colli functions optimally to control the cervical lordosis during CCF while Longus Capitis controls CCF with cervical flexion (CF) (Cagnie et al., 2008).

2. The Best CS exercises.

Acute cervical pain

During acute cervical pain and dysfunction distorted neuromuscular function occurs between the superficial and DCF and needs to be relearnt by selective CCF training using a Pressure Biofeedback (Stabilizer Chattanooga South Pacific Australia) (Falla et al., 2003a; Falla et al., 2003b; Jull et al., 2008; Jull et al., 2009). Promoting good posture by lifting the sternum and nodding ‘yes’ will increase DCF activation, reduce cervical lordosis and improve the muscular force-length relationship (Falla et al., 2007). Others, however, promote good posture by advising to ‘stick the chest out and avoid shoulder protraction’ (Weinberg, 2003; Charbonneau et al., 2012).
Various cervical strengthening (CS) methods exist, e.g. manual isometrics, buddy- assisted- and swissball CS, wrestling forwards- and back-bridging (www.boksmart.co.za, Frounfelter, 2008), theraband (www.thera-bandacademy.com) and isokinetic training.

Cervical extensors

Cervical extensors are strengthened with higher loads with good results (Ylinen et al., 2003; Falla et al., 2013). An increased CSA and noted neuromuscular adaptations showed improvement of the Splenius Capitus, Semispinalis Capitis & Cervicis and Multifidus after dynamic high resistance exercise in healthy subjects (Conley et al., 1997a). Furthermore after 12 weeks of high load training, T2 MRI investigations showed hypertrophic changes of 25% for the DCE (Conley et al., 1997b). The optimum position where Semispinalis muscle works is at 15 degrees CF in extension (Elliott et al., 2010).

Theraband

Using low cost Theraband for isometric, concentric and eccentric CS, which can be performed in any direction. Initially, starting with isometric training in the neutral position reduced risk of injury to the cervical structures exist (Qureshi & Hecht, 2010). However, research has shown that painful necks of females can be strengthened with a high load of 1x15reps of 80% of maximal isometric contraction 5x.week-1, and then reduced to 3x.week-1. Theraband has significantly strengthened isometric cervical flexion (+110%), Rotation (+76%), and extension (+69%) in combination with aerobic exercises (Ylinen et al., 2003). In the 2 year – follow-up muscle strength had improved by 44% flexion and rotation together with 27% in extension (Ylinen et al., 2006). Cervicogenic headache in females improved by using high loading strengthening and endurance Theraband exercises 5x.week-1 (Ylinen et al., 2010). Theraband can safely be used during initial rehabilitation to reduce pain and headache by doing relatively high isometric resistance 3-5x.week-1.
In a study of fighter pilots during flight, EMG muscle activation was recorded to determine how much training load is required to avoid injury at various Gz-levels. At low Gz-levels (+1Gz) training load should be performed at 15% of a maximal voluntary contraction (MVC). Training with Theraband is indicated for athletes who participate at very low G-forces or during initial rehabilitation (Netto et al., 2007).
It has been shown that Theraband causes lower EMG peak muscle activation in comparison to Cybex and provides less resistance during strengthening (Burnett et al., 2008).

Isokinetics

Dynamic strengthening and progressive loading with isokinetics are used effectively in final rehabilitation or injury prevention in healthy subjects. It has been shown that training at 3x.week-1 for 12 weeks with progressive loading increases muscle strength. Male aviators followed a dynamic resistance programme for flexion and extension at 40% and 75% of 10RM, but were tested isometrically and dynamically. Isometric improvement shown after 4 weeks was 32.7% and at 8 weeks it was 32.7%. Extension improved in all the weeks significantly. Dynamic strength improved 39.2% after 8 weeks and 49.3% at 12 weeks (Taylor et al., 2006). Strength training duration should be 10-12 weeks for neural adaptation and hypertrophic changes to take place in the muscle (Taylor et al., 2006). It is evident that dynamic testing values are much higher which may question differences of assessment methods. Isokinetic strength training is measured with ease, however due to differing equipment used during studies and different populations it is challenging to make a reliable comparison between studies. Additionally isokinetic units are expensive and training is not performed in a sport specific position (Burnett et al., 2008).

Multi-Cervical Unit (MVU)

The MVU is used in the aviation industry. A study was performed using dynamic concentric and eccentric loading at 24-114% of MVC for 2x.week-1 for a duration of 10 weeks. It demonstrated MVC significantly improved isometric neck strength (64.4% Flexion; 62.9% Extension; and 62.9% Left lateral flexion) in comparison to Control. Theraband improved 42% for Flexion only (Burnett et. al, 2005).

Rugby trends

Interestingly, good results have been shown in current rugby trends (iCSP-discussion), using a dynamic force equalising system (patent 2012-E80664(56) that permits active rotation and movement while functional training takes place to enhance the head being stationary and integrating reflex activity of the senses and vestibulum (www.gatheresystems.com, Peek & Gatherer, 2005; Brooks & Kemp, 2011). The system causes strengthening in an active movement and is controlled. It excludes harmful axial and shear forces during training in sport specific positioning. It can be used for rehabilitation and injury prevention. Further investigation is required.

3. Is strength training effective for rehabilitation and injury prevention?

Pain conditions: CS and reduced pain

Low load craniocervical flexion and higher load strength and endurance exercises in females (Randløv et al., 1998; Ylinen et al., 2003; Falla et al., 2007 & 2013) together with both genders (Highland et al., 1992; Jordan et al., 1998; Chiu et al., 2005) and longer term training (Ylinen et al., 2006; Ylinen et al., 2010) have been shown to reduce cervical pain and improve strength. In long term studies, patient compliance influenced results (Hakkinen et al., 2008). Pain can influence the strength training measurements. By measuring the effect on the sympathetic nervous system it has been shown that exercise can provide immediate pain relief response (O’Leary et al., 2007). CS in combination with other passive modalities can also reduce pain (Jordan et al., 1998; Bronfort et al., 2001). Furthermore, improvements observed in the control groups is explained by fear reduction, a biological variant or due to frequent testing that reduces pain (Ylinen et al., 2003; Chiu et al., 2005). This shows the importance of using randomised controlled studies.

Healthy subjects: CS improvements, gender and age

CS has improved in healthy subjects but usually at higher loading (Pollock et al., 1993; Conley 1997a & 1997b; Jordan et al,1999; Burnett et al., 2005; Mansell et al., 2005; Taylor et al., 2006). Some of these results would be influenced by including both genders in a study. Males have higher isometric neck strength compared to females during flexion (20%) and extension (25%) (Jordan et al., 1999). Females sustain higher acceleration forces post-strength training (Mansell et al., 2005), hence during whiplash injuries, acceleration speeds sustainable in different genders vary for males and females: 5g and 3.5g-force respectively (Vasavada et al., 2001). In addition females have smaller heads and reduced anterior-posterior dimension of C3-C7 vertebrae influencing the acceleration force and explains why women are more prone to whiplash (Jordan et al., 1999; Vasavada et al., 2008). Studies indicate that age or gender difference does not change the fibre composition (Boyed-Clarke et al., 2001). Nevertheless, due to these facts mixed gender studies should be assessed with caution.

Protective equipment

Protective equipment and improved skill help avoid neck injuries. In a comparative neck strength study, no differences were found between asymptomatic aviators exposed to G-forces and non-aviators (Seng et al., 2003). It was suggested that it was due to the use of protective equipment. Technique modification is also suggested in rugby to prevent injuries (Brooks & Kemp, 2010). Training positions needs to be taken in account when strengthening and enhanced tackling skills according to player position will prevent injuries (McIntosh et al., 2010).

Correct Training mode

A certain training mode would produce specific results (O’Leary et al., 2012). A study that used slow isoinertial CS in football, resulted in minimal improvements with no EMG muscle activation changes whilst performing a tackle. In another study, involving footballers, an 8 week isotonic resistance programme was performed and head-neck dynamic stability was then tested by unanticipated weights that were dropped from a small height. Although the isometric strength did improve by 15%, no dynamic head-neck segment stability, muscle stiffness or EMG differences, were found (Mansell et al., 2005). Plyometric training was suggested. It is possible that insufficient loading was used in training and that exercises were not in a dynamic mode or perhaps an insufficient motor learning pattern (Lisman, 2009; Falla et al., 2013). Specific strength training requires a specific training mode to achieve the end goal.

Anticipation

It is suggested that during an anticipation action, muscle tone would increase however if the impact is unanticipated an injury would occur (Mihalik et al., 2011). During tackling, the axial loading causes loss of the cervical lordosis and subsequent buckling. Injuries occur in 2-31ms (measured at direct vertical loading while the player will be in an oblique position) while muscle reflex activating only happens at 60ms, however a certain amount of muscle stiffness would be present (Nightingale et al., 1996; Nightingale et al., 2000). Hence, if the player is able to anticipate the impact and by increasing the tone and stiffness, the impact may be reduced with lower risk of injury, indicating CS as a means of injury prevention.

Proprioception

Proprioception resistance training improves muscle strength. A recent study demonstrated that resistance together with proprioception improved cervical strength by 29.3% while the CSA increased by 18.9%-32.3% while the resistance only group improved by 8.9-9.9% (Kramer et al., 2013). Proprioception facilitates a neuromuscular response where the brain stimulates the cervical muscles causing hypertrophic changes in the proprioceptive group. The cervical spine needs to balance the head and stabilise the senses. There is an interaction between the vision stimuli and vestibular sense organ of the head together with the proprioceptors of the neck. In addition vision has a huge effect on the cervical spine muscle activation to perform at an optimum level (Keshner et al., 1995).

4. Further studies

Further high quality studies should aim to standardise muscle strengthening measurements in sporting populations. Further research should explore the integration of proprioceptive training in strengthening programmes to enhance neuromuscular response for improvement of rehabilitation and injury prevention.

Conclusion

Cervical strengthening is used in the rehabilitation of cervical injuries and injury prevention of collision and G-force related sports. Strength training that integrates correcting the neuromuscular performance of DCE and DCF and then progressing with loading has shown to be successful in rehabilitation of cervical injuries. The programme needs to take factors like fatigue and pain and gender into account to optimise results. CS for injuries has not been refuted but may not be a single modality to achieve optimum response. Other protection, for example safety equipment and skill may provide additional benefit to prevent injuries. Further studies needs to consider the implementation of more neuromuscular training in combination with strength training to deliver optimum results in rehabilitation and for injury prevention in sport.

References

• Anderson, J.S., Hsu, A.W., & Vasavada, A.N., (2005). Morphology Architecture and biomechanics of human cervical multifidus. Spine, 30(4): E86-E91
• Burnett, A.F., Coleman, J.L., & Netto, K.J., (2008). An eletromyographic comparison of Neck conditioning Exercises in Healthy Controls. Journal of Strength and Conditioning Association, 22(2): 447-454.
• Burnett, A.F., Naumann, F.L., Price, R.S., & Sanders, R.H., (2005). A comparison of training methods to increase neck muscle strength. Work, 25(3): 205-210.
• Boyed-Clarke, L.C., Briggs, C.A., & Galea, M.P., (2001). Comparative histochemical composition of muscle fibres in a pre- and a postvertebral muscle of the cervical spine. Journal of Anatomy, 199(6): 709-716.
• Boyed Clarke, L.C., Briggs, C.A., & Galea, M.P., (2002). Muscle spindle distribution, morphology and density in longus colli and multifidus muscle of the cervical spine. Spine, 27(7): 694-701.
• Brooks, J.H.M., Fuller, C.W., Kemp, S.P.T., & Reddin, D.B., (2005). Epidemiology of injuries in English professional rugby union: part 1 match injuries. British Journal of Sports Medicine, 39(1): 757-766.
• Brooks, J.H., & Kemp, S.P., (2010). Injury prevention priorities according to playing position in professional rugby union players. British Journal of Sports Medicine, 45, 765-775.
• Brooks, J.H., & Kemp, S.P., (2011). Injury priorities according to playing position in professional rugby union players. British Journal of Sports Medicine, 45: 765-775.
• Bronfort, G., Evans, R., Nelson, B., Aker, P.D., Goldsmith, C.H., & Vernon, H., (2001). A randomised control clinical trial of exercise and spinal manipulation for patients with chronic neck pain. Spine, 26(7): 788-797.
• Cagnie, B., Dickx, N., Peeters, I., Tuytens, J., Achten, E., Cambier, D., & Danneels, L., (2008). The use of functional MRI to evaluate cervical flexor activity during different cervical flexion exercises. Journal of Applied Physiology, 104(1): 230-235.
• Charbonneau, R.M.E., McVeigh, S.A., & Thompson, K., (2012). Brachial neuropraxia in Canadian Atlantic University Sport Football Players: What is the incidence of Stingers? Clinical Journal of Sports Medicine, 22(6): 472-477.
• Chiu, T.T.W., Lam, T., & Hedley, A.J., (2005). A randomised controlled trial on the efficacy of exercise for patients with chronic neck pain. Spine, 30(1): E1-E7.
• Conley, M.S., Stone, M.H., Nimmons, M., & Dudley, G.A., (1997a). Resistance training and human cervical muscle recruitment plasticity. Journal of Applied Physiology, 83(6): 2105-2111.
• Conley, M.S., Stone, M.H., Nimmons, M., & Dudley, G.A., (1997b). Specificity of resistance training responses in neck muscle size and strength. European Journal of applied Physiology and Occupational Physiology, 75(5): 443-448.
• Clancy, W.G., Brand, R.I., & Bergfield J.A., (1977). Upper trunk brachial plexus injuries in contact sports, American Journal of Sports Medicine, 5:209-216.
• Di Benedetto, M., & Markey, K., (1984). Electrodiagnostic localization of traumatic upper trunk brachial plexopathy. Archives of Physical Medicine and Rehabilitation, 65, 15–17.
• Elliott, J.M., Jull, G., Noteboom, J.T., Darnell, R., Galloway, G., & Gibbon, W.W., (2006). Fatty infiltration in the cervical extensor muscles in persistent whiplash-associated disorders: a magnetic resonance imaging analysis. Spine 31:E847-855.
• Elliott, J.M., Jull, G., Noteboom, J.T., & Galloway, G., (2008). MRI cross sectional area for the cervical extensor musculature in patients with persistent whiplash associated disorders (WAD). Manual Therapy, 13: 258-265.
• Elliott, J.M., O’Leary, S.P., Cagnie, B., Durbridge, G., Danneels, L., & Jull G., (2010). Craniocervical orientation affects muscle activation when exercising the cervical extensors in healthy subjects. Archives of Physical Medicine and Rehabilitation, 91: 1418-1422.
• Engebretsen, L., Steffen, K., Alonso, J.M., Aubry, M., Dvorak, J., Junge, A., Meeuwisse, W., Mountjoy, M., Renstrom, P., & Wilkinson, M., (2010). Sports injuries and illnesses during the Winter Olympic Games 2010. British Journal of Sports Medicine, 44: 772-780.
• Falla, D., Jull, G., Dall’Alba, P., Rainoldi, A., & Merletti, R., (2003a). An electromyographic analysis of the deep cervical flexor muscles during cranio-cervical flexion. Physical Therapy, 83(10): 899–906.
• Falla, D., Rainoldi, A., Merletti, R., & Jull, G., (2003b). Myoelectric manifestations of sternocleidomastoid and anterior scalene muscle fatigue in chronic neck pain patients. Clinical Neurophysiology, 114(3): 488–495.
• Falla, D., Bilenkij, G., & Jull, G., (2004a). Chronic neck pain patients demonstrate altered patterns of muscle activation during performance of a functional upper limb task. Spine, 29(13): 1436-1440.
• Falla, D., Jull, G., Edwards, S., Koh, K., & Rainoldi, A., (2004b). Neuromuscular efficiency of the sternocleidomastoid and anterior scalene muscles in patients with neck pain. Disability and Rehabilitation, 26(12): 712-717.
• Falla, D., Jull, G., & Hodges, P., (2004c). Neck pain patients demonstrate reduced activation of the deep neck flexor muscles during performance of the cranio-cervical flexion test. Spine, 19: 165-172.
• Falla, D., Jull, G., & Hodges, P.W., (2004d). Feedforward activity of the cervical flexor muscles during voluntary arm movements is delayed in chronic neck pain. Experimental Brain Research, 157(1): 43-48.
• Falla, D., Jull, G., Rainoldi, A., & Merletti, R., (2004e). Neck flexor muscle fatigue is side specific in patients with unilateral neck pain. European Journal of Pain, 8(1): 71–77.
• Falla, D., Rainoldi, A., Merletti, R., & Jull, G., (2004g). Spatio-temporal evaluation of neck muscle activation during postural perturbations. Journal of Electromyography and Kinesiology, 14(4): 463–474.
• Falla, D., Rainoldi, A., Jull, G., Stavrou, G., Tsao, H., (2004f). Lack of correlation between sternocleidomastoid and scalene muscle fatigability and duration of symptoms in chronic neck pain patients. Neurophysiologie Clinique, 34(3-4): 159-165.
• Falla, D., O’Leary, S., Fagan, A., & Jull, G., (2007). Recruitment of the deep cervical flexors muscles during a postural-correction exercise performed in sitting. Manual Therapy, 12(2): 139-143.
• Falla, D., Lindstrom, R., Rechter, L., Boudreau, S., & Petzke, F., (2013). Effectiveness of an 8-week exercise programme on pain and specificity of neck muscle activity in patients with chronic neck pain. A randomised controlled study. European Journal of Pain, 17(10): 1517-1528.
• Frounfelter, G., (2008). Selected Exercises for strengthening the cervical spine in adolescent rugby participants. Strength and Conditioning Journal, 30(3): 23-28.
• Hakkinen, A., Kautiainen, H., Hannonen, P., Ylinen, J., (2008). Strength training and stretching versus stretching only in the treatment of patients with chronic neck pain: a reandomised one-year follow-up study. Clinical Rehabilitation, 22: 592-600.
• Highland, T.R., Dreisinger, T.E., Vie, L.L., & Russell, G.S., (1992). Changes in isometric strength and range of motion of the isolated cervical spine after eight weeks of clinical rehabilitation. Spine, 17(6 Supplement): S77-S82.
• Jordan, A., Bendix, T., Nielsen, H., Hansen, F.R., Høst, D., & Winkel, A., (1998). Intensive training, physiotherapy, or manipulation for patients with chronic neck pain. A prospective single-blinded randomised clinical trial. Spine, 23(3): 311-318.
• Jordan, A., Mehlsen, J., Bulow, P.M., Ostergaard, K., & Danneskiold-Samsøe, B., (1999). Maximal isometric strength of the cervical musculature in 100 healthy volunteers. Spine 24(13): 1343-1348.
• Jull, G.A., Falla, D.L, Vicenzino, B., & Hodges, P.W., (2009). The effect of therapeutic exercise on activation of the deep cervical flexor muscles in people with chronic neck pain. Manual therapy 14(6): 696-701.
• Jull, G.A., O’Leary, S.P., & Falla, D.L., (2008). Clinical Assessment of the Deep Cervical Flexor Muscles: The Craniocervical Flexion Test. Journal of Manipulative and Physiological Therapeutics, 31(7): 525–533.
• Keshner, E.A., Cromwell, R.L., & Peterson, B.W.(1995). Mechanisms controlling human head stabilisation. Head-neck characteristics during random rotations in the vertical plane. Journal of Neurophysiology, 73(6): 2302-2312.
• Kramer, M., Hohl, K., Bockholt, U., Schneider, F., Dehner, C., (2013). Training effects of combined resistance and proprioceptive neck muscle exercising. Journal of Back and Musculoskeletal Rehabilitation, 26(2): 189-197.
• Levitz, C.J., Reilly, P.J., & Torg, J.S. (1997). The pathomechanics of chronic, recurrent cervical nerve root neuropraxia – The Chronic Burner syndrome. American Journal of Sports Medicine, 25(1): 73-76.
• Lisman P.J., (2009). Slow iso-inertial cervical strength does not alter dynamic stability of the head and neck during a standard football tackle. PhD Dissertation, University of Miami.
• Mansell, J., Tierney, R.T., Sitler, M.R., Swanik, K.A., & Stearne, D., (2005). Resistance training and head-neck segment dynamic stabilisation in male and female soccer players. Journal of Athletic Training, 40(4):310-319.
• Mansfield, N.J., & Marshall, J.M., (2001). Symptoms of Musculoskeletal disorders in stage rally drivers and co-drivers. British Journal of Sports Medicine, 35(5): 314-320.
• Mayoux-Benhamou, M.A., Revel, M., Vallee, C., Roudier, R., Barbet, J.P., & Bargy, F., (1994). Longus Colli has a postural function on cervical curvature. Surgical and Radiologic Anatomy. 16(4) 367-371.
• McIntosh, A.S., Savage, T.N., McCorory, P., Frechede, B.O., & Wolfe, R., (2010). Tackle characteristics and injury in a cross section of rugby union football. Medicine and Science in Sport and Exercise. 42(5): 977-984.
• Mihalik, J.P., Guskiewicz, K.M., Marshall, S.W., Greenwald, R.M., Blackburn, J.T., & Cantu, R.C., (2011). Does cervical muscle strength in youth ice hockey players affect head impact biomechanics? Clinical Journal of Sport Medicine, 21(5): 416-421.
• Minoyama O., & Tsuchida H., (2004). Injuries in professional motor car racing drivers at a racing circuit between 1996 and 2000. British Journal of Sports Medicine, 38(5): 613-616.
• Meyer, S.A., Schulte, K.R., Callaghan, J.J., Albright, J.P., Powell, J.W., Crowley, E.T., el-Khoury, G.Y., (1994). Cervical Spinal Stenosis and Stingers in Collegiate Football players. The American Journal of Sports Medicine, 22(2): 158-166.
• Netto, K., Burnett, A., Coleman , J.L, (2007). Neck exercises compared to muscle activation during aerial combat maneuvers. Aviation, Space, and Environmental Medicine, 78(5): 478-484.
• Nightingale, R.W., Camacho, D.L., Armstrong, A.J., Robinette, J.J., & Meyers, B.S., (2000). Inertial properties and loading rates affecting buckling modes and injury mechanisms in the cervical spine. Journal of Biomechanics, 33(2): 191-197.
• Nightingale, R.W., McElhaney, J.H., Richardson, W.J., Best, T.M., & Myers, B.S., (1996). Experimental impact injury to the cervical spine: Relating motion of the head and the mechanism of injury. Journal of Bone and Joint Surgery – American Volume, 78(3): 412-421.
• O’Leary, S., Cagnie, B., Reeve, A., Jull, G.A., & Elliott, J., (2013). Is there altered activity of the extensor muscles in chonic mechanical neck pain? A functional magnetic resonance imaging study. Archives of Physical Medicine and Rehabilitation, 92(6): 929-934.
• O’Leary, S., Falla, D., Hodges, P., Jull, G., & Vicenzino, B., (2007). Specific therapeutic exercise of the neck induces immediate local hypoalgesia. The Journal of Pain, 8(11): 832-839.
• O’Leary, S., Jull, G.A., Kim, M., Uthaikhup, S., & Vicenzino, B., (2012). Training mode-dependent changes in motor performance in neck pain. Archives of Physical Medicine and Rehabilitation, 93(7): 1225-1233.
• Panjabi, M.M., (1992a). The stabilising system of the spine. Part I, function, dysfunction, adaptation and enhancement. Journal of Spinal Disorders, 5(4): 383-389.
• Panjabi, M.M., (1992b). The stabilizing system of the spine. Part II, Neutral zone and instability hypothesis. Journal of Spinal disorders, 5(4): 390-397.
• Peek, K., & Gatherer D., (2005). The rehabilitation of a professional Rugby Union player following a C7/T1 posterior microdiscectomy. Physical Therapy in Sport, 6(4): 195-200.
• Peolsson, A.L.C., Peolsson, M.N., Jull, G.A., & O’Leary, S.P., (2013). Cervical muscle activity during loaded arm lifts in patients 10 years postsurgery for cervical disc disease. Journal of Manipulative and Physiological Therapeutics, 36(5): 292-299.
• Pollock, M.L., Graves, J.E., Bamman, M.M., Leggett, S.H., Carpenter, D.M., Carr, C., Cirulli, J., Matkozich, J., & Fulton, M., (1993). Frequency and volume of resistance training: effect on cervical extension strength. Archives of Physical Medicine and Rehabilitation, 74(10) 1080-1086.
• Qureshi, S.A., & Hecht, A.C., (2010). Burner syndrome and cervical cord neuropraxia. Seminars in Spinal Surgery, 22(4): 193-197.
• Randløv, A., Ostergaard, M., Manniche, C., Kryger, P., Jordan, A., Heegrad, S., & Holm, B., (1998). Intensive dynamic training for females with chronic neck/shoulder pain. A randomised controlled trial. Clinical Rehabilitation, 12(3): 200-210.
• Seng, K.Y., Lam, P.M., & Lee, V.S., (2003). Acceleration effects on neck muscle strength: pilots vs. non-pilots. Aviation, Space, and Environmental Medicine, 74(2): 164-168.
• Taylor, M.K., Hodgdon, J.A., Griswold, L., Miller, A., Roberts, D.E., & Escamilla, R.F., (2006). Cervical resistance training: Effects on isometric and dynamic strength. Aviation, Space and Environmental Medicine, 77(11): 1131-1135.
• Tierney, R.T., Sitler, M.R., Swanik, C.B., Swanik, K.A., Higgins, M., & Torg, J., (2005). Gender differences in head-neck segment dynamic stabilization during head acceleration. Medicine and Science in Sports and Exercise, 37(2): 272-279.
• Tierney, R.T., Higgins, M., Caswell, S.V., Brady, J., McHardy, K., Driban, J.B., & Darvish, K., (2008). Sex differences in head acceleration during heading while wearing soccer headgear. Journal of Athletic Training, 43(6): 578-584.
• Torg, J.S., Pavlov, H., Genuario, S.E., Sennett, B., Wisneski, R.J., Robie, B.H., & Jahre, C., (1986). Neuropraxia of the cervical spinal cord with transient quadriplegia. Journal of Bone and Joint Surgery, 68(9): 1354-1370.
• Vasavada, A.N., Li, S., Delp, S.L., (2001). Three-dimensional isometric strength of neck muscles in humans. Spine, 26(17): 1904-1909.
• Vasavada, A.N., Danaraj, J., Siegmund, G.P., (2008). Head and neck anthropometry, vertebral geometry and neck strength in height-matched men and women. Journal of Biomechanics, 41(1): 114-121.
• Vasavada, A.N., Li, S., Delp, S.L., (1998). Influence of muscle morphometry and moment arms on the moment-generating capacity of human neck muscles. Spine, 23(4): 412–422.
• Watkins, R.G., (1986). Neck injuries in football players. Clinics in Sports Medicine, 5(2):215-246.
• Weinberg, J., Rokito, S., & Silbet, J.S., (2003). Etiology, treatment and prevention of athletic ‘stingers’. Clinics in Sports Medicine, 22(3): 493-500.
• Uhlig, Y., Weber, B.R., Grob, D., & Müntener, M., (1995). Fibre composition and fibre transformations in the neck muscles of patients with dysfunction of the cervical spine. Journal of Orthopaedic Research, 13(2): 240-249.
• Ylinen, J., Takala, E.P., Nykänen, M., Häkkinen, A., Mälkiä, E., Pohjolainen, T., Karppi, S.L., Kautiainen, H., & Airaksinen, O., (2003). Active neck muscle training in the treatment of chronic neck pain in women A Randomised control study. Journal of the American Medical Association, 289(19): 2509-2516.
• Ylinen, J.J., Takala, E.P., Nykänen, M.J., Kautiainen, H.J., Häkkinen, A.H., & Airaksinen, O.V., (2006). Effects of twelve month strength training subsequent to twelve month stretching exercise in treatment of chronic neck pain. Journal of Strength and Conditioning Research, 20(2): 304-308.
• Ylinen, J., Nikander, R., Nykänen, M., Kautiainen, H., & Häkkinen, A., (2010). Effect of neck exercises on cervicogenic headaches. A Randomised Control study. Journal of Rehabilitation Medicine, 42(4): 344-349.
• Chartered Society of Physiotherapy : ICSP Interactive discussion : www.csp.org.uk/icps/clinical-cases/cervical-disc-prolapse-return-rugby demonstrating current trends in rugby cervical rehabilitation accessed 12/11/2013
• Formula 1 – dictionary : http://www.formula1-dictionary.net/g_force.html access 8/11/2013
• Benson A,. BBC Sport , F1: Fernando Alonso suffering persistent headaches http://www.bbc.co.uk/sport/0/formula1/24976578 accessed 22/11/2013
• The Gatherer system http://www.gatherersysems.com/ accessed 22/11/2013
• Thera-band academy www.thera-bandacademy.com accessed 22/11/2013
• South African Rugby – Boksmart. http://www.sarugby.co.za/boksmart/pdf/BokSmart%20-%20Neck%20Injury%20Prevention.pdf accessed 22/11/2013
• The Official Olympic Website of the Olympic Movement. http://www.olympic.org/skeleton accessed 12/11/2013

Disclaimer

The contents of this article – Spine Injuries in Sport, is aimed at medical professionals. It is provided here for informational purposes only and should not be treated as medical or health management advice. The materials herein are not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your doctor, physiotherapist or other health care provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read in this article or website. Reliance on any information provided herein is solely at your own risk.

Copyright

The content of this article – Spine Injuries in Sport, is copyright © 2025 of Suegnet Meyer and Meyer & Associates. Transmission or reproduction of the contents, beyond that allowed by fair use as defined in the copyright laws requires the written permission of the copyright owners. Please provide proper attribution when referencing or sharing content.

The post Spine Injuries in Sport first appeared on Meyer Physio.

Introduction

Vertical jump (VJ) determines explosive lower limb power (Linthorne, 2001). This discussion highlights the VJ kinetic and kinematic pattern and the biomechanical factors maximising vertical jump height (VJH). Furthermore, VJ measurements are analysed and VJ as a basketball performance measure is assessed.

1. Kinetic & Kinematic analysis

Various VJ techniques take place in a sagittal plane. The squat jump (SJ) starts from a stationary semi-squat position excluding the pre-stretching phase. The countermovement jump (CMJ) phases:

Standing stationary

CMJ is performed from an upright position. The Body Mass (BM) equals ground reaction force (GRF) (Newton’s 1st law) (Blazevich, 2007).

Unweighting

The body’s inertia needs to be overcome (Newton’s 2nd law). The feet apply vertical force against the ground and vice versa (Newton’s 3rd law). Inertia is overcome and GRF cause COM acceleration downward (Linthorne, 2001).

Propulsion

The pre-stretching downwards muscle lengthening counteraction is the eccentric phase of the stretch-shortening (SSC), allowing hip and knee flexion with ankle dorsi-flexion (Komi, 1992). Muscle stretching reduces downward COM speed however downward force still causes negative acceleration. When resultant forces and COM acceleration reach zero, GRF is equal to BM marking maximum downward velocity (Linthorne, 2001). Large hip torque is produced at the first 2/3 of the propulsion phase (Feltner et al., 1999). Starting the second part of the SSC, concentric leg muscle action causes upward force while the COM is still moving downwards. Upward acceleration is initiated (Komi, 1992). At the lowest counter-movement point, COM is at rest and velocity is zero. Maximum lower limb muscle contraction produces force causing almost maximum GRF.

Take-off

Rapid upward movement due to SSC occurs until take-off (Komi, 1992). Hip extension, followed by knee and ankle plantar-flexion cause positive net joint movements (Umberger, 1998). High velocity and vertical COM displacement with maximum GRF occur early in the take-off phase. Maximum velocity is reached when GRF and BW equalise just before toes-off. Resultant forces cause COM acceleration (Linthorne, 2001). GRF is zero and COM rises higher than at the start due to ankle plantar-flexion until toes-off.

2. Biomechanics maximising VJ

Take-off parameters that influence VJ : Force(F); vertical velocity(v); acceleration(a); mass(m); and displacement of COM(d_com).

Power(P)= F. , F= m.a , Work(W)=F. d_com, Torque(τ)=F.d , Angular Momentum(H)= Inertia(I) x angular velocity(ω),
Angular acceleration(α)= τ.I, Impulse(J)=F x time(t)

Ρ = F ᵡ v
F = Μ ˣ ɑ
W = F ˣ d_com
τ = F ˣ d
H = I ˣ ω

α = τ ˣ I

J = F ˣ t

F ᵡ M ᵪ a ᵡ M ᵪ τ ˣ τ _ˣ a ₓ t

Segments and joint contribution

Arm Swing (AS) raises the COM higher with increased velocity at take-off, increasing COM acceleration of all body segments. The AS contributes to reducing hip and knee torque in early propulsion. In later propulsion, AS slows trunk extension down enhancing hip torque thus prolonging the concentric extensor action leading to increased force and torque generation. (Feltner et al., 2004). During the last part of take- off, maximum energy is released, increasing power output and work that increase VJH (Vanezis & Lees, 2005).
(τ ↑ due to T=F.d, α= τ.I I=constant thus α↑ and F=ma, F ↑ , a ↑, P ↑due P=F.v and W ↑ due W= F.dcom)

If BW reduces, segmental mass will reduce resulting in reduction of segmental moments of inertia. This will lead to an increased angular velocity (H= ↓I. ↑ω). This will also contribute to vertical velocity to raise the COM (Blazevich, 2007).

Muscle capabilities

Muscles contract from proximal to distal to coordinate VJ (Pandy & Zajac, 1991). Creating force to maximise COM vertical displacement, requires optimum muscle capabilities. This is influenced by genetics (Vanezis & Lees, 2005). Muscle force is determined by the type of muscle fibre, muscle size and length, neural activation and control, calcium phosphorylation supplying energy, angular and contraction velocity and strength-to-mass ratio (Waller et al., 2013). Increased amount of fast twitch muscle fibres (IIa and IIx) characterises higher force production due to increased contraction speed and increased ATPase concentrations (Bosco & Komi, 1979; Kraemer & Spiering, 2006). (P= F.v)

Force-length relationship of muscles

This describes how muscle can produce force in relation to contractile and elastic features of the muscle (Enoka, 2008). The contractile (sarcomere) component creates maximal force when all cross-bridges are attached. If sarcomere length increases or decreases, force production reduces. The elastic component will generate force if a contracting muscle is stretched (Bobbert et al., 2001). The total force is the sum of contractile and elastic force components.

Force–Velocity relationship

This describes the muscle force production changes according to muscle length velocity. (Enoka, 2008). Maximal muscle force is created with no shortening eg. Isometric contraction. When a load exceeds the force generated by the muscle, it will lengthen and more force will be produced. The rate of change of muscle activation is determined by the muscle activation together with the force-length and force-velocity parameters (Domire & Challis, 2007).

Force-time relationship

Muscles that take more time to generate maximum force in the eccentric phase of the counter movement will produce higher force. Fast twitch muscles have faster ramping-up force qualities e.g. knee extensors. Bobbert et al. (1996), compared higher CMJ to SJ height. Increased ramp-up time during the countermovement caused the extensor muscles to take longer to reach maximum force, reducing knee joint moments with slower cross-bridging during the eccentric phase. Starting the concentric phase, more force could be produced.

Biarticular (BiM) and Monoarticular (MonoM) muscles

BiM spans over 2 joints and couples movement over these joints (Enoka, 2008). At the start of the countermovement, MonoM flexors (Iliopsoas, Biceps femoris short head, Tibialis anterior) facilitate the countermovement. MonoM extensors (Gluteus maximus, Vasti, Soleus) produce VJ propulsion energy with a high force-velocity relationship creating metabolic energy. BiM (Rectus Femoris, Hamstrings) with low work and power output, is responsible for transferring energy and refine coordination (Nagano et al., 2005). Activating BiM and MonoM in various sequences and ranges of motion, result in redistribution of extensor and flexors torque, increasing vertical translation of the COM (Jacobs et al., 1996).

Stretch-Shortening Cycle (SSC)

During CMJ the SSC is caused by the hip, knee and ankle extensors that actively stretch prior to shortening, increasing positive work and power (Cavagna, 1977 & Kwakami, 2002). The SSC contributes to VJ by:
i. Increased time to develop force in the eccentric phase.
ii. Storage and release of elastic energy causing force production when muscles are stretched (eccentric phase) hence increasing kinetic energy available and improving work capacity at the beginning of the concentric phase (Nagano et al., 2005). Kopper et al. (2013) suggest that storing and re-using elastic energy can increase vertical velocity especially with larger countermotion. Plyometric training increases the eccentric muscle activity since the release timing of stored elastic energy increases force output in the concentric phase. (McBride et al., 2008)
iii. Stretch reflex. A forced muscle lengthening causes a stretch reflex at the start of the SSC increasing muscle tension. This will improve concentric behaviour. For the stretch reflex to increase effectively, the intensity of change of direction from eccentric to concentric needs to be increased e.g. drop-jump (Waller et al., 2013)
iv. Increasing the rate of force development (RFD) during the concentric phase e.g. in SJ. By increasing knee flexion during the static starting position followed by rapid triple extension of hips, knees and ankles, RFD will increase (Wilson et al., 1995).

Take-off parameters are optimised by increasing force and power production, COM acceleration and vertical velocity and BM reduction. This will increase the COM displacement that will optimise the VJ.

3. VJ Measurements

Various VJ tests result in different measurements. Valid test methods are required to determine exercise programmes and lower limb explosive power (Bobbert & Van Soest, 1994). Validity indicates whether equipment measures what it claims to measure (Atkinson & Nevill, 1998). Reliability is the ability to reproduce a test with consistent measurements (Bruton et al., 2000). Reliability can increase by using a sizable population (50 participants) and performing 3 trials. To increase reliability, specific VJ must be performed in a homogenous population (Young et al., 1997).
Sargent’s test measures the difference between the fully extended-stand-reach and the maximal jump-and-reach height (Sargent, 1921). This is a cheap and easy test performed next to a wall, but concentrating on jumping and reaching to make a mark may be difficult. Calculation errors are possible causing low reliability and validity (Klavora, 2000). The Vertec System also tests jump-and-reach height but use equipment with horizontal vanes (Nuzzo et al., 2011). Moir et al. (2008) stated that adequate shoulder movement as well as precise timing and coordination is required to perform these measurements. Training is required to ensure that the participant makes contact with the vanes at peak height (Moir et al., 2004).
The Contact Mat (CMT) (Innervations) is sensitive to pressure during lift-off and landing, recording the flight time (Aragon–Vargas 2000). The flight time measurement is used to calculate VJH (jump height = [t2 × g] ÷ 8, where g = acceleration due to gravity with t = flight time) (Markovic et al., 2004). Leard et al. (2007) insists that accurate and reliable VJH calculations can be obtained when performing a correct CMJ and landing. The take-off and landing must be in the same foot position to not influence the CMT measurement (Markovic et al., 2004). However, Moir et al. (2008) found a systematic error using CMT: By using the flight time method, males do excessive knee flexion during flight, increasing the flight time thus overestimating VJ. Aragon–Vargas (2000) argued that a position error (COM rise-height) prior to take-off influences the calculations. However, Buckthorpe et al. (2012/) corrected the rise-height error but still found a significant difference measuring VJH by CMT versus Force Platform (FP). This demonstrates the CMT being reliable but having a weak validity.
Toronto Waist Belt tests determine height by a measuring tape that is fixed to the mat between the feet. When performing the VJ, the tape extends and stops at maximum height. No calculations are required, making the reading easy and valid (Klavora, 2000, Buckthorpe et al., 2012).
The accelerometer is a small simple device attached to the hip. The BM must be entered prior to testing. It can determine VJH on any surface (e.g. sand) by either measuring flight time or the take-off velocity (VJH=maximal velocity2/[2xg]). The latter proved unreliable (Casertelli et al., 2010). Based on the flight time, only bilateral VJH is relatively reliable (McCurdy et al., 2011; Nuzzo et al., 2011).
Optojump photoelectric cells measure GRF and flight time. Flight time and acceleration can calculate COM vertical rise (Glatthorn et al., 2011). It can be interchangeable with FP measurements (VJH = 1.02 x optoVJH + 0.29) and used in the field with good reliability and validity compared to FP (Coefficient of Variation (CV) 2.7%; Intra Class Coefficient (ICC) 0.982-0.989) (Glatthorn et al., 2011).
Young et al. (1997) found a high reliability for the Vertec jumps in a small (n=17) male population, performing a 1-arm reaching VJ. The Vertec vanes were 1cm apart. However, Nuzzo et al. (2011) compared the Vertec, CMT, and accelerometer and found highest reliability for the accelerometer followed by the CMT and the Vertec. This CMJ with bilateral arm swing study consisted of a moderate size mixed gender group. The Vertec vanes were 1.27cm placed apart for this study. They found that training of the population influenced the VJH, especially when using the Vertec. In contrast to this result Moir et al. (2008) found CMJ with arms around necks, in females (n=35) and males (n=35) tested over 4 weeks on a CMT was highly reliable with high ICC and low CV. These authors noted that it was more reliable to take the highest VJH instead of an average VJH due to fatigue and skill.
The FP and 3-D motion video analysis (3DVA) are the ‘gold standard’ for determining VJH. 3DVA calculates the precise COM position as well as COM of each body segment. VJH is calculated by the difference of standing COM and peak flight COM position (Aragon–Vargas, 2000).
FP is laboratory based; expensive; floor mounted; and can calculate numerous measurements including VJH, rate of power development, etc. (Naves et al., 2009, Buckthorpe et al., 2012). Calculations to determine VJH is more complex. GRF is measured by analysing the pressure on the FP. The quartz crystal transducer FP (Krisler) is most accurate (Buckthorpe et al., 2012). Mobile FP can also be used with high validity (Buckthorpe et al., 2012). Some of the FP calculation methods have been questioned (Aragon–Vargas, 2000). Moir et al. (2008) propose 3 different methods of calculating VJH:
1. Flight Time: VJH = 1/2g (t/2)2
2. Vertical Velocity of the COM at take-off method (TOV= TOV2/2g). This method is the most valid and reliable (Aragon–Vargas, 2000, Moir et al., 2008)
3. Adding the vertical COM displacement prior to take-off to the height calculated using TOV.
FP is the most reliable and valid VJH measurement using TOV method. Field testing with an Optojump is also highly reliable and valid whereas an accelerometer is small and simple to use but less valid and less reliable.

4. Basketball

Basketball requires maximum anaerobic power production to perform high intensity movements including, walking, short distance running and jumping in defence (blocking) and offence (shooting).
Scanlan et al. (2011), compared sub-elite and elite players. Elite players produced higher power and work production. Jumping ability is a requirement regardless of playing position. Maximising jump skill is required when defending or opposing counterparts (Ziv & Lidor, 2010).
During matches up to 46 VJ will be performed and reaching heights of up to 75cm (McInnes et al., 2010). Playing positions have different demands. Correlation between body composition, aerobic fitness, anaerobic power and positional roles exist (Ostojic et al., 2006). Delextrat & Cohen (2009) analysed basketball jumps performed in playing position with good reliability (ICC of 0.95). They found guards perform frequent 1leg-jumps during lay-ups. Forwards do not jump as high, perhaps due to a lack of coordination although power output is uniform in all positions. Forwards and centres perform frequent bilateral jumping. The CMJ with arm swing is more specific to basketball indicating that specific playing positions require specific VJ performance testing (Ziv & Lidor, 2010).
McGill et al. (2012) raised concerns that current tests may not be sport specific. However, Hoffman et al. (1991) noted that VJH and playtime have a significant correlation. Delextrat & Cohen (2008) assessed agility T-test, sprint and CMJ with AS, comparing recreational and elite players. The field tests demonstrated a significant VJ difference (8.8%), between the 2 groups. Due to variation in laboratory versus field testing reliability, isokinetic knee extensor testing was performed with the elites with significant higher peak torque values compared to their recreational counterparts. Furthermore, Alemdaroglu, (2012), determined the relationship between muscle strength, anaerobic performance, agility, sprinting and basketball VJ. It demonstrated significant correlation between isokinetic quadriceps peak power performance, CMJ and SJ.
Basketball jump-shots are frequently performed from a distance to the basket, in an attempt to score. The player is required to vary direction, generate momentum and overcome inertia by activating the leg muscle power (McInnes et al., 2010). The run-up towards the basket is in a curved line creating centripetal and centrifugal forces. Every step generates vertical and horizontal forces with increased horizontal and vertical velocity until braking force is applied. A bilateral CMJ is performed as discussed earlier. By creating a large force in a short time a higher impulse will be produced whilst lifting the arms up above head with 90° elbows flexion and then extending the elbows and increasing the COM. The ball is propelled by a projectile movement towards the basket. Balance, coordination and trunk stability is important. This shot requires power behind the ball and VJ as high as possible, especially in the presence of a blocking defender.
VJ is frequently executed in basketball. It is therefore indicative to use VJ as a performance test and predictor but must be specific to playing position.

REFERENCES

• Alemdaroglu, U. (2012). The relationship between muscle strength, anaerobic performance, agility, sprint ability and vertical jump performance in professional basketball players. Journal of Human Kinetics, 31, 99-106.
• Aragon-Vargas, L.F. (2000). Evaluation of four vertical jump tests, Methodology, reliability, validity and accuracy. Measurement in Physical ,Education and Exercise Science, 4(4), 215-228.
• Atkinson, G., & Nevill AM, (1998). Statistical methods for assessing measurement error (reliability) in variable relevant to sports medicine. Sports Medicine, 26,217-238.
• Blazevich, A. (2007). Sports Biomechanics the basics: optimising human performance. London. A&C Black Publisher Ltd.
• Bobbert, M.F., & Van Soest, A.J. (1994). Effects of muscle strengthening on vertical jump height. A simulated study. Medicine and Science in Sports and Exercise, 26(8), 1012-1020.
• Bobbert, M.F. (2001). Dependence of human squat jump performance on the series elastic compliance of the Triceps Surae: a simulated study. Journal of Experimental Biology, 204, 533-542.
• Bobbert, M.F., Gerritsen, K.M.G.M., Littjens, M.C.A. & Van Soest, A.J. (1996). Why is countermovement jump height greater than squat jump height? Medicine and Science in Sport and Exercise, 28: 1402-1412 .
• Bosco,C. & Kombi,P.V. (1979). Mechanical characteristics and fibre composition of human leg extensor muscles. European Journal of Applied Physiology, 41,275-284.
• Bruton, A., Conway, J.H., & Holgate, S.T. (2000). Reliability: What is it, and how is it measured? Physiotherapy, 86,(2), 94–99.
• Buckthorpe, M., Morris, J., & Folland, J.P. (2011). Validity of vertical jump measurement devices, Journal of Sports Sciences, 30(1), 63-69.
• Casertelli, N., Muller, R., & Maffiuletti, N.A. (2010). Validity and reliability of the Myotest accelerometer system for the assessment of vertical jump height. Journal of Strength and Conditioning Research, 24(11), 3186-3193.
• Cavagna GA (1977). Storage and utilisation of elastic energy in skeletal muscle. Exercise in Sport Science Reviewed (5) 89-129.
• Delextrat, A., & Cohen, D. (2008). Physiological testing of basketball players: Towards a standard evaluation of anaerobic fitness. Journal of Strength and Conditioning Research, 22(4), 1066-1072.
• Delextrat, A., & Cohen, D. (2009). Strength, power, speed and agility of women basketball players according to playing position. Journal of Strength and Conditioning Research, 23(7), 1974-1981.
• Domire, Z.J. & Challis, J.H. (2007). The influence of an elastic tendon on the force producing capabilities of a muscle during dynamic movements. Computer Methods in Biomechanics and Biomedical Engineering, 10(5), 337-341.
• Enoka, R.M. (2008). Neuromechanics of human movement ,4th edition, 240-250, Human Kinetics, New Zealand.
• Feltner, M.E., Fraschetti, D.J., & Crisp, R.J. (1999). Upper extremity augmentation of lower extremity kinetics during countermovement vertical jumps. Journal of Sports Science, 17, 449-466.
• Feltner, M.E., Bishop, E.J, & Perez C.M, (2004). Segmental and kinetic contributions in vertical jumps performed with and without arm swing. Research Quarterly For Exercise and Sport , 75(3), 216-230.
• Glatthorn, J.F., Gouge, S., Nussbaumer, S., Stauffacher, S., Impellizzeri, F.M., & Maffiuletti, N.A. (2011). Validity and reliability of Optojump photoelectric cells for estimating vertical jump height. Journal of Strength and Conditioning Research, 25(2), 556-560.
• Hoffman, J.R., Fry, A., Howard, R., Maresh, C.M., & Kraemer, W.J. (1991). Strength and speed and endurance changes during the course of a division 1 Basketball season. Journal of Applied Sport Science Research, 5, 144-149.
• Jacobs, R., Bobbert, M.F. & Van Ingen Schenau, G.J. (1996). Mechanical output from individual muscles during explosive leg extensions: the role of biarticular muscles. Journal of Biomechanics, 29, 513–523.
• Kwakami, Y., Muraoka, T., Ito, S., Kanehisa, H. & Fukunaga, T. (2002). In vivo muscle fibre behaviour during counter-movement exercise in humans reveals a significant role for tendon elasticity. The Journal of Physiology, 540, (4), 635-646.
• Klavora, P. (2000). Vertical jump tests:A critical review. Strength & Conditioning Journal, 22(5), 70-75.
• Komi, P.V. (1992). Stretch-shortening cycle. Strength and Power in Sports. Komi, P.V.(Ed) London : Blackwell Science ,169-179.
• Kopper, B., Csende, Z., Sáfár, S., Hortobágyi, T., & Tihanyi, J. (2013). Muscle activation history at different vertical jumps and its influence on vertical velocity. Journal of Electromyography & Kinesiology, 23(1),132-139.
• Kraemer, W.J. & Spiering, B.A. (2006) Skeletal muscle physiology: Plasticity and response to exercise. Hormonal Research, 66(1), 2-16.
• Leard, J.S., Cirillo, M.A., Katsnelson, E., Kimiatek, D.A., Miller, T.W., & Trebincevic, K. (2007). Validity of two alternative systems for measuring vertical jump height. Journal of Strength and Conditioning Research, 21(4), 1296-1299.
• Lees, A., Van Renterghem, J., & De Clercq, D. (2004). Understanding how an arm swing enhances performance in the vertical jump. Journal of Biomechanics, 37(12), 1929-1940.
• Linthorne, N.P. (2001). Analysis of standing vertical jumps using a force platform. American Journal of Physics, 69(11), 1198-1204.
• Luthanen, P. & Kombi, R.V. (1978). Segmental contributions to force in vertical jump . European Journal of applied physiology and Occupations Physiology, 15, 38(3)181-8.
• Markovic, G., Dizdar, D., Jukic, I., & Cardinale, M. (2004). Reliability and Factorial Validity of Squat and Countermovement Jump Tests. Journal of Strength and Conditioning Research, 18(3), 551-555.
• McBride, J.M., McCaulley, G.O., & Cormie, P. (2008). Influence of preactivity and eccentric muscle activity on concentric performance during vertical jumping. Journal of Strength and Conditioning Research, 22(3), 750-757.
• McCurdy, K.W., Ransone, J., Guerrero, M., Miller, B., & Walker, J. (2011). Reliability of kinematic and kinetic measures of jump performance using accelerometry. Journal of Strength and Conditioning Research, 25, 80-86.
• McGill, S.M., Andersen, J.T., & Horne, A.D. (2012). Predicting performance and injury resilience from movement quality and fitness scores in a basketball team over 2 years. Journal of Strength and Conditioning Research, 26(7), 1731-1739.
• McInnes, S.E., Carlson, J.S., Jones, C.J., & McKenna, M.J. (1995). The physiological load imposed on basketball players during competition. Journal of Sports Sciences, 13(5), 387-397.
• Moir, G., Button, C., Glaister, M., & Stone, M.H. (2004). Influence of familiarization on the reliability of vertical jump and acceleration sprinting performance in physically active males. Journal of Strength and Conditioning Research, 18(2), 276-280.
• Moir, G., Shastri, P., & Connaboy, C. (2008). Intersession reliability of vertical jump height in males and females. Journal of Strength and Conditioning Research, 22(6), 1779-1784.
• Nagano, A; Komura, T; Fukashiro, S. (2005). Force, work and power output of lower limb muscles during human maximal-effort countermovement jumping. Journal of Electromyography and Kinesiology, 15(4), 367-376.
• Naves, L.M., Pereira, A.A., Andrarde, A.O., & Soares, A.B. (2009). Design and evaluation of a biomechanical system for athletes performance analysis. Journal of Measurement, 42(3), 449-455.
• Nuzzo, J.L., Anning, J.H., & Scharfenberg, J.M. (2011). The Reliability of Three Devices Used for Measuring Vertical Jump Height. Journal of Strength and Conditioning Research, 25(9), 2580-2590.
• Ostojic, S.M., Mazic, S., & Dikic, N. (2006). Profiling in basketball: physical and physiological characteristics of the elite players. Journal of Strength and Conditioning Research, 20(4), 740-744.
• Pandy., M., & Zajac, F. (1991). Optimal Muscle Coordination Strategies for Jumping. Journal of Biomechanics. 24(1), 1-10.
• Sargent, D.A. (1921). The physical test of man. American Physical Education Review, 26, 188-194.
• Scanlan, A., Dascombe, B., & Reaburn, B. (2011). A comparison of the activity demands of elite and sub-elite Australian men’s basketball competition. Journal of Sports Sciences, 29(11), 1153-1160.
• Umberger, B.R. (1998). Mechanics of the vertical jump and two-joint muscles: implications for training. Strength and Conditioning Journal, 20(5), 70-74.
• Vanezis, A., & Lees, A. (2005). A Biomechanical analysis of good and poor performers of the vertical jump. Ergonomics, 48(11-14), 1594-1603.
• Waller, M., Gersick, M., & Holman, D. (2013). Various Jump training styles for improvement of vertical jump performance. Strength and Conditioning Journal, 35(1), 82-89.
• Wilson, G.J., Lyttle, A.D., Ostrowski, K.J., & Murphy, A.J. (1995). A comparison of rate of force development tests. Journal of Strength and Conditioning Research, 9(3),176-181.
• Young, W., MacDonald, C.H., Heggen, T., & Fitzpatrick, J. (1997). An evaluation of the specificity, validity and reliability of jumping tests. Journal of Sports Medicine and Physical Fitness, 37(4), 240-245.
• Ziv, G., & Lidor, R. (2010). Vertical jump in female and male basketball players – a review of observational and experimental studies. Journal of Science and Medicine in Sport, 13(3), 332-339.
• Krisler Instrument Corporation, Amherst, NY. http://www.kistler.com/ accessed 2-5-2013.
• Innervation, Muncie, IN. http://www.innervations.com/ accessed 2-5-2013.

Disclaimer

The contents of this article – Biomechanical Analysis and Measurement of Vertical Jump as a Performance Indicator in Basketball, is aimed at medical professionals. It is provided here for informational purposes only and should not be treated as medical or health management advice. The materials herein are not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your doctor, physiotherapist or other health care provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read in this article or website. Reliance on any information provided herein is solely at your own risk.

Copyright

The content of this article – Biomechanical Analysis and Measurement of Vertical Jump as a Performance Indicator in Basketball, is copyright © 2016 of Suegnet Meyer and Meyer & Associates. Transmission or reproduction of the contents, beyond that allowed by fair use as defined in the copyright laws requires the written permission of the copyright owners.

The post Biomechanical Analysis and Measurement of Vertical Jump as a Performance Indicator in Basketball first appeared on Meyer Physio.