Assessing Outcomes in People With Chronic Ankle Instability: The Ability of Functional Performance Tests to Measure Deficits in Physical Function and Perceived Instability

Study Design Laboratory-based, cross-sectional study. Background Functional performance tests (FPTs) assess short bouts of unilateral hops for either distance or speed. More research is needed to identify specific FPTs that may be useful for measuring asymmetry outcomes related to functional performance and perceived instability deficits in individuals with chronic ankle instability (CAI). Objectives To identify FPTs that are sensitive to subjective and objective deficits associated with CAI. Methods Twenty-four subjects with unilateral CAI (10 male, 14 female; mean ± SD age, 20.7 ± 3.0 years) and 24 healthy, matched controls (10 male, 14 female; age, 20.1 ± 2.6 years) completed 5 unilateral FPTs in random order. Mean FPT scores and functional symmetry percentages were calculated and compared between groups using 2 separate 1-way multivariate analyses of variance (MANOVAs). Perceived instability symmetry percentages were compared between groups using a Mann-Whitney U analysis. Results There were no differences in the mean FPT scores (P>.05) or functional symmetry percentages (P>.05) between groups for any of the 5 FPTs. However, participants with CAI perceived greater instability when using their involved limb during the side hop (P = .02), 6-meter crossover hop (P = .003), lateral hop (P = .007), and figure-of-eight hop (P = .008). Conclusion There were no differences in mean functional scores between groups for all 5 FPTs, and each group performed symmetrically. Regardless, administering a visual analog scale following the completion of the side hop, 6-meter crossover hop, lateral hop, and figure-of-eight hop tests captures subjective reports of perceived instability in the involved limb that can be compared bilaterally throughout treatment. J Orthop Sports Phys Ther 2018;48(5):372-380. Epub 30 Mar 2018. doi:10.2519/jospt.2018.7514.