Analysis of Ankle Laxity, Self-reported Function, and Perceived Instability in Chronic Ankle Instability, Coper, and Control Groups

Abstract

PURPOSE:This study aimed to identify differences in ankle laxity in chronic ankle instability (CAI), coper, and control groups, and a correlation between ankle laxity, self-reported function, and perceived instability.METHODS: Sixty-six participants (22 CAI patients, 22 copers, and 22 controls) selected by recommendations of the International Ankle Consortium volunteered for this study. Foot and Ankle Ability Measure Activities of Daily Living (FAAM-ADL), FAAM-Sports, and Ankle Instability Instrument (AII) were used to assess participants’ self-reported function and perceived instability. The FAAMADL and FAAM-Sports are reported as a percentage. Higher scores indicate better function. The AII is reported as “yes” responses while more “yes” responses indicate higher instability. Three trials of anterior/posterior (A/P) displacement and inversion/eversion (I/E) displacement were assessed by an instrumented ankle arthrometer. Greater displacement indicates higher laxity. The ankle positioned in sagittal- and frontal-plane neutral while A/P and I/E displacement were assessed with 125 N and 4 N-m, respectively. The means of three trials were used for data analysis. One-way ANOVA and Tukey post-hoc comparisons (α=0.05) were performed to identify differences in ankle laxity between groups. Pearson correlation analysis was performed to identify a relationship between ankle laxity, self-reported function, and perceived instability.RESULTS: CAI patients show greater A/P displacement compared to control group (p<.03), and greater I/E displacement compared to coper and control groups (p<.03). Several positive and negative correlations were found between ankle laxity, self-reported function, and perceived instability (p<.00).CONCLUSIONS: As self-reported function and perceived instability are correlated with greater laxity (I/E displacement), improving static stability (ankle laxity) may play an important role in improving perceived ankle function and instability in CAI.