Dynamic Postural Stability Deficits Exist in Mechanically Lax Individuals but not those with Perceived Functional Ankle Instability

Lateral ankle sprains are among the most frequent athletic injuries. Lateral ankle sprains have been reported to recur at a rate in excess of 80%, and chronic ankle instability (CAI) is a frequent and serious pathologic consequence of sprains that develops in up to 50% of those with a history of ankle sprain [1]. These individuals often present with feelings of “giving way” and reports of sudden instability, which are characteristic of CAI. Contributing factors to CAI are debated, but contemporary theories include failure of the dynamic restraint mechanism resulting from proprioceptive deficiencies and/or excess mechanical ligamentous laxity [2]. The purpose of this study was to determine if differences exist in dynamic postural stability among healthy controls, copers, functionally unstable ankle individuals, and those with both functional instability and mechanical ankle laxity.