Sinus Tarsi Syndrome is a condition that occurs commonly in the athletic population but is often missed and treated as a peroneal muscle disfunction. Which is a real shame, because when treated appropriately, Sinus tarsi syndrome is easily managed and requires minimal adaptations to workload.
The sinus tarsi refers to an anatomical tunnel that runs between the two bones of the heel (Talus and Calcaneus, called the subtalar joint). Typically, this joint is very stable and experiences little to no movement during weightbearing activities. However, in an ankle that has experienced trauma to the lateral ligaments from an inversion sprain the sinus tarsi can become acutely inflamed. This is due to increased shearing forces that occur in the subtalar joint when the ankle lacks stability. Therefore, this condition can occur alongside an acute ankle sprain or because of recurrent ankle instability. Inflammation of the sinus tarsi causes localised lateral and/or medial ankle pain over the site of the sinus tarsi in weightbearing positions typically walking/running on uneven surfaces.
Sinus tarsi syndrome responds well to heel lock taping and anti-inflammatory treatment, allowing an athlete to minimise their training deload whilst managing their symptoms. Longer term management may involve proprioceptive retraining of your affected ankle. Your local physio will be able to provide you with relevant advice and management of your condition, tailored specifically to you, so if this sounds like you, book an appointment to have them take a look!