Question
Can you explain posterior ankle impingement?
Answer
With anterior ankle impingement, people have limitations in dorsiflexion. The client may have osteophytes or something on the anterior surface of the talus. With posterior ankle impingement, there can actually be an osteophyte on the posterior surface. Essentially, when the ankle comes into plantar flexion, it will impinge in the same way and create symptoms in the back of the ankle. Some people consider an os trigonum and a posterior ankle impingement to be the same thing.
Any abnormality within the tissue itself that limits motion can create pain. The hard part is that it is going to create symptoms directly behind the Achilles tendon. It is also going to create an inflammatory process. When you palpate, it may be painful. Sometimes it is difficult to tease out, because everything through that region hurts. The advice that I give, whether it is a posterior ankle impingement or os trigonum, is that if you suspect that diagnosis and yet there are no improvements with treatment, it may be worth getting a radiograph to make sure that the bony integrity is there and that there is not an os trigonum, a loose body, or some other type of impingement.
These clients are also going to have pain when doing a heel raise. Think about the Achilles tendon with a person in a standing position. You have them come up on their toes, and ask if that hurts. Yes is their answer. Is it because they are firing the gastroc soleus and Achilles complex, or is it because they are going into their full range of plantar flexion that they are actually impinging?
