Some restraint to further injury is offered by the structures on the inside of the ankle, the medial malleolus and the medial collateral ligament.
It is designed to identify lesions of the pyramidal tract, via stimulation of the skin over the lateral malleolus.
The medial malleolus is a bony process extending distally off the medial tibia.
The medial malleolus is the prominence on the inner side of the ankle, formed by the lower end of the tibia.
Together, their tendons pass behind the lateral malleolus.
The fibers of the "superior retinaculum" ("external annular ligament") are attached above to the lateral malleolus and below to the lateral surface of the calcaneus.
The talus then moves laterally, shearing off the lateral malleolus or, more commonly, breaking the fibula superior to the tibiofibular syndesmosis.
It is when you have subluxation/dislocation of the peroneal tendons about the lateral malleolus.
