What?What?Whaat the…is that? I know, another funny name to add to this blog “sinus tarsi syndrome“. Let´s start from the beginning, let´s define sinus tarsi for those who don´t know what it is, although I am sure that if you were searching on google and you found this article it is because you were an unlucky person who got injured.
Sinus tarsi is a cavity located exactly where you usually get pain when you get the most common ankle sprain, lateral ankle sprain. For those who know a bit of anatomy, this cavity is located between the calcaneus and the talus bones. In this cavity there are many structures as ligaments, tendons, vessels or joint capsule.
Now, let´s go to the point, what is sinus tarsi syndrome? As usual, I think that the best way to explain what an injury is about is by telling you what the different words that name it mean.
Sinus: it is a cavity within a bone or other tissue.
Tarsi: it is the plural form of tarsus, tarsus being a set of seven bones located between the lower leg bones (fibula and tibia) and the metatarsus.
Syndrome: it is the association of symptoms and signs of a condition, the cause of which can be known or not. The reality is that this term is used very often to name injuries or conditions of unknown cause.
Video by BodyParts3D is made by DBCLS. (Polygon data is from BodyParts3D) [CC BY-SA 2.1 jp ], via Wikimedia Commons
Yes, I know, so far you have no idea what sinus tarsi syndrome is. Well, sorry, it is necessary to know the basics to get to know the injury.
Sinus tarsi syndrome is a condition characterized by anterolateral ankle pain that occurs when you have had traumatic injuries to the ankle. By traumatic injuries, I mean ankle sprains or repetitive strain due to an excessive stress in the area as result of, for instance, using wrong footwear.
The sinus tarsi is filled with many connective tissues which contribute to the stability and proprioception of your ankle. When these tissues are damaged, mainly the ligaments, this will result in talocrural joint instability ( joint where the foot and the leg meet and which movements are plantarflexion and dorsiflexion of the foot). Also, according to research, when you get talocrural joint instability, this might be associated to subtalar joint instability (joint between talus and calcaneus bones, also called talocalcaneal joint/articulation, which movements are eversion and inversion of the foot).
As for many other injuries, there are many things we don´t know about sinus tarsi syndrome. There are some authors that relate sinus tarsi syndrome with subtalar joint instability. In this article by Keefe DT et al. you can find more information about subtalar joint instability.
Symptoms and signs of sinus tarsi syndrome
Sinus tarsi syndrome is usually characterized by:
- Instability of the foot and ankle when walking on uneven ground, running and with sprinting activities.
- Possible talocrural joint instability.
- Deep anterolateral ankle pain.
- Pain over the sinus tarsi at the end of range of foot supination with ankle plantarflexion (inversion).
- Possible loss of strength of the muscles involved (calf muscles: gastrocnemius, soleus, tibialis posterior, peroneal muscles-peroneus longus and brevis-; tibialis anterior, among others)
- Poor proprioception which will mean poor control, due to the fact that ligaments are affected.
- Cutting and jumping activities on hard surfaces will be very difficult.
This is a condition poorly understood by health professionals which can make patients be frustrated. I will be glad if you can add some extra information to this blog post by leaving a comment or contacting us on The Physical Therapy Southampton Physiotherapy Clinic.