Posterior ankle impingement

--What causes posterior ankle impingement?

The cause of the impingement in this condition differs from person to person. Often the causes are soft tissue structures at the back of the ankle, such as the joint capsule and covering of the ankle (synovium), and ligaments at the back of the ankle. In some people, the impingement may be due to a small extra bone in the back of the ankle called an ‘os trigonum’ that is present in about 10 per cent of adults (having an os trigonum doesn’t guarantee that you will get this condition). Other people have a slightly more prominent bony point at the back of their bone in the ankle joint (talus), which can cause the impingement. Remember though, you may have the same features on your other ankle that are not painful, so be sure to discuss how relevant any imaging may be (or not) with your physiotherapist or GP. 

--How do I know if I have posterior ankle impingement?

Posterior ankle impingement causes pain at the back of the ankle when the foot is pointed (plantarflexed) and when the structures mentioned above become caught or impinged. This condition may sometimes also begin after a previous ankle sprain. Importantly, the pain should only be present when in loaded plantarflexion, and won’t affect day-to-day activity. Your physiotherapist will be able to diagnose this condition, and may ask you about what activities you do and any previous foot or ankle injuries. They will try and reproduce your symptoms by getting you to do the activity that provokes your pain, and may perform some special tests that force the ankle into plantarflexion. Scans and imaging are not required unless you are not responsive to treatment.

--How can physiotherapy help with posterior ankle impingement?

Your physiotherapist will be able to help design a treatment plan to settle your pain. This will usually consist of a period of offloading from the aggravating activity, such as avoiding time en pointe or reducing kicking loads for a period. Medications may be advised to help settle any pain or associated inflammation if needed.

Your physiotherapist may perform mobilisation and distraction (gentle pulling on the joint to gap the irritated parts) techniques to the ankle joint that may also help to settle symptoms and improve joint mobility. Strengthening exercises will be prescribed for the calf, as well as for any deficits identified further up the leg. It will be important to initially avoid having the foot fully pointed during strengthening exercises.

Finally, it will be important to assess your technique, particularly in performance sports such as dancing or gymnastics. In ballet dancers, turning out of the foot while on toes may lead to the condition, and any issues should be identified and changed as part of rehabilitation. In some cases, the condition may persist and sometimes requires a corticosteroid injection to settle the pain. Your physiotherapist will be able to organise a referral for you, if this is required; however, this should not be the first line of treatment and should always be followed by a thorough rehabilitation of at least six weeks.

--How effective is physiotherapy for posterior ankle impingement?

Currently, no clinical trials have examined the effect of physiotherapy on posterior ankle impingement. Most research on this topic relates to surgical case reports and anatomical studies, investigating the cause of impingement. Expert opinions would suggest always trialling a lengthy period of conservative management before moving towards injection or surgery only in severe and stubborn cases.

--What can I do at home?

In the early stages of this condition, it will be important to avoid having your ankle in forced plantarflexion (toes pointed). This will help to settle down any irritation before beginning a slow progression back to normal activities. You will likely be given tailored strengthening exercises for the calf as well as other lower leg muscles if deficits are identified. You will also be able to do other forms of exercises for cross training, as long as the aggravating position is avoided to begin with.

--How long until I feel better?

How quick you return depends on what activity you are completing. For ballet dancers, because of the extended time ‘en pointe,’ rehabilitation may take 2–6 months. For kicking sports such as football or soccer, activity may not need to be limited as much; however, the condition may also require ongoing treatment for the following months.