Achilles Tendinopathy
Achilles tendinopathy is a common cause of heel pain and lower calf pain, with stiffness at the back of the ankle. It affects runners and athletes, but it is just as common in people who are not especially active. The Achilles is the large tendon connecting the calf muscles to the heel bone, and it takes considerable force every time you walk, run or jump. The condition is still often called Achilles tendonitis, or tendinitis, although that name is misleading. The problem is usually a change in the structure and load tolerance of the tendon, not simple inflammation.
Signs and symptoms
The main symptoms are pain and stiffness in the tendon just above the heel bone. It usually develops gradually and is often most noticeable after rest, particularly first thing in the morning or after sitting for a while. Early on the pain may ease once you get moving, then return with prolonged walking, running or exercise. Over time it can appear after exercise and eventually during it. The tendon may look slightly swollen and feel stiff or thickened to touch.
Where is your Achilles pain?
The location of the pain matters more than anything else on this page, because the two main patterns of Achilles tendinopathy are treated differently. Where an injection is appropriate at all, the site of your pain determines which one.
Mid-portion Achilles tendinopathy
This causes pain, and sometimes visible thickening, within the tendon itself, usually several centimetres above the heel. Stiffness after rest is typical. Where rehabilitation alone has not settled it, a high-volume injection around the tendon is the option usually considered.
Insertional Achilles tendinopathy
Insertional tendinopathy affects the lower part of the Achilles where it attaches to the heel bone, or calcaneus. The pain sits directly at the back of the heel and is often aggravated by walking uphill, running, or footwear pressing on the area. High-volume injection is not the treatment here. Where an injection is appropriate, it is a guided steroid injection into the retrocalcaneal bursa, and only when that bursa is genuinely contributing to symptoms.
Haglund deformity. Some people also have a Haglund deformity, a bony prominence at the upper back of the heel bone. It can alter the space around the Achilles insertion and may irritate the tendon and the retrocalcaneal bursa, which lies between the tendon and the bone. A Haglund deformity does not necessarily cause pain, though. Plenty of people have a prominent heel and no symptoms at all, so finding one on imaging means little on its own and has to be read alongside the examination and the exact site of your pain.
Why does Achilles tendinopathy develop?
Tendons adapt to the loads placed on them, and tendinopathy develops when the demand outstrips that capacity. It is often described as an overuse injury, and it commonly follows a sudden increase in walking, running or training, though there is not always an obvious trigger. Age, previous injury, calf strength, body weight, certain medications and general health all influence how a tendon copes.
The useful question in clinic is not what the tendon looks like, but whether it can currently tolerate what you are asking of it.
Common contributing factors include:
- An increase in activity — distance, speed or hills
- Too little recovery time between training sessions
- A change of footwear or training surface, such as moving from grass to hard courts
- Weakness in the calf muscles or posterior chain
- Reduced ankle range of motion, usually from tight calf muscles
- Running uphill, which stretches the tendon further on every stride and tires it sooner
- Overpronation, where the foot rolls in and the lower leg rotates inwards, placing twisting stress on the tendon
- Wearing high heels regularly, which shortens the tendon and calf muscles, so exercising in flat shoes then loads the tendon beyond its usual range
- Diabetes, obesity, smoking and some neurological conditions
Do I need an ultrasound scan?
Not everyone with Achilles pain needs imaging. Many cases can be diagnosed from the history and clinical examination, and rehabilitation can begin without a scan.
Diagnostic ultrasound is most useful when symptoms are persistent, the diagnosis is uncertain, there is significant swelling, or a partial tear is suspected. It lets us assess the thickness and structure of the tendon and the tissues around it, look for associated problems such as retrocalcaneal bursitis, and examine the Achilles dynamically while the ankle moves. An X-ray can help where the bony prominence or other changes within the heel bone need assessing, and MRI is occasionally indicated where further detail is required.
Scan findings do not always match symptoms. Some people have marked structural change and no pain at all. We therefore read the images alongside your symptoms and examination rather than treating the scan on its own.
Physiotherapy and progressive loading
For most people, progressive rehabilitation is the main treatment. The tendon needs an appropriate amount of load to rebuild strength and capacity, so complete rest is rarely a long-term answer. The aim is to find a level of activity the tendon tolerates and build steadily from there.
Physiotherapy usually involves progressive calf strengthening and a gradual increase in the demands placed on the tendon. For runners and athletes, that eventually works up to the loads required for running, jumping and sport. Which exercises you do, and how much, are the main determinants of how well you recover.
What you can do yourself
- Reduce the load on the tendon initially, then increase it gradually
- Wear supportive footwear
- A small heel raise in each shoe can reduce load and ease pain when walking, and suits some patients better than others
- Ice during a reactive flare-up
- Ibuprofen during a reactive flare-up, if appropriate for you and advised by your GP or pharmacist
Injection options, and which applies to you
Persistent Achilles tendinopathy can be frustrating and recovery takes time. Depending on the presentation, other measures may be considered alongside rehabilitation, including footwear modification and heel lifts in selected cases. Where an injection is appropriate, which one depends on where your pain is.
High-volume injection — for mid-portion tendinopathy
A high-volume injection may be considered for persistent mid-portion Achilles tendinopathy that has not improved with appropriate rehabilitation. A relatively large volume of fluid is injected under ultrasound guidance around the tendon rather than into it, to separate it from the surrounding tissues and act on the small blood vessels and pain-sensitive nerve fibres that can develop around a longstanding tendinopathy.
The evidence for high-volume injections is mixed and the procedure does not suit everyone. It belongs within a wider rehabilitation programme, not in place of tendon loading.
Steroid injection — for retrocalcaneal bursitis with insertional pain
Where significant retrocalcaneal bursitis is contributing to insertional heel pain, an ultrasound-guided steroid injection, sometimes called a cortisone injection, into the bursa may occasionally be considered.
This needs careful assessment, because the bursa sits immediately against the Achilles tendon. The injection goes into the bursa, not into the tendon, and ultrasound guidance is what makes that distinction reliable. It is not a routine treatment for Achilles pain and it is not a substitute for rehabilitation.
If symptoms persist
Where insertional symptoms remain significant despite appropriate non-surgical treatment, referral to a specialist foot and ankle surgeon is sometimes appropriate.
A high-volume injection may be considered for persistent mid-portion Achilles tendinopathy that has not improved with appropriate rehabilitation. A relatively large volume of fluid is injected under ultrasound guidance around the tendon rather than into it, to separate it from the surrounding tissues and act on the small blood vessels and pain-sensitive nerve fibres that can develop around a longstanding tendinopathy.
The evidence for high-volume injections is mixed and the procedure does not suit everyone. It belongs within a wider rehabilitation programme, not in place of tendon loading.
Achilles tendon tears
Sudden Achilles pain is a different problem from tendinopathy and needs to be treated as such. A partial rupture or a complete tear can happen during a push-off, jump or change of direction. People often describe hearing a pop, or feeling as though they have been kicked in the back of the ankle.
A suspected acute Achilles rupture needs prompt assessment. Ultrasound can help in selected cases to assess whether the tendon is still continuous and how extensive the injury is, though further imaging or orthopaedic assessment may be required.
Monitoring recovery
For some Achilles injuries, ultrasound can be used alongside clinical assessment to track progress. A tendon does not have to look normal on a scan before you can return to activity. The decision to return to running or sport rests on symptoms, strength, function, load tolerance and clinical assessment, with imaging adding information where it is useful.
At Meyer Physio we treat the person and the functional problem in front of us, not an abnormal-looking tendon on a screen.
Written by Suegnet Meyer, Advanced Practice Musculoskeletal Physiotherapist and MSK Sonographer. HCPC registered [PH55635]. Chartered Society of Physiotherapy member [66175].