Self-Assessed Disability and Functional Performance in Individuals With and Without Ankle Instability: A Case Control Study

Abstract
Single-blind case-control study. To compare functional performance and self-assessed disability scores among individuals with and without chronic ankle instability (CAI) and uninjured controls. After an acute lateral ankle sprain, CAI develops in 40% to 75% of all individuals. However, some individuals, copers, maintain high-level activities after an ankle sprain and do not develop CAI. Studying differences between copers and those with CAI is the first step in developing a clinical battery of tests that can accurately determine which individuals are more likely to develop CAI after an acute lateral ankle sprain. Participants were 24 active adults with unilateral CAI (mean +/- SD age, 21.7 +/- 2.8 years), 24 copers (20.8 +/- 1.5 years), and 24 uninjured controls (21.8 +/- 2.6 years). Participants completed 3 questionnaires of self-assessed disability: (1) Foot and Ankle Disability Index, (2) Foot and Ankle Disability Index-Sport, and (3) a questionnaire of ankle function. Four hop tests were also completed: (1) figure-8 hop, (2) side-to-side hop, (3) triple-crossover hop, and (4) single-leg hop for distance. Self-assessed disability was significantly different among groups (P<.001), but hop test scores (P = .259) were not. Those with CAI had greater self-assessed disability than copers and uninjured controls. Copers and uninjured controls did not differ in self-assessed disability or functional performance. Self-assessed disability is significantly greater in those with CAI than copersand uninjured controls. However, functional performance, measured by hop tests, did not differ among groups.