Functional ankle instability (FAI) may be prevalent in as many as 40% of patients following an acute sprain of the lateral ligament complex. Damage to mechanoreceptors within the lateral ligaments has been hypothesized to interrupt neurological feedback mechanisms resulting in FAI. Altered afferent output from joint mechanoreceptors following injury or effusion is known to result in weakness of surrounding joint musculature, a phenomenon referred to as arthrogenic muscle response (AMR). AMR may be the underlying cause of FAI promoting a cyclic inhibition of the ankle joint musculature.
The overall goal of this investigation is to examine role of the dynamic ankle stabilizers in resisting sudden ankle inversion while walking in patients classified as functionally unstable. We hypothesize that the peroneal musculature will be inhibited hindering the dynamic control about the ankle in patients who suffer from FAI.