Correlation between the Foot and Ankle Disability Index (FADI) Score and Strength of HIP and Knee Muscles in Subjects with Unilateral Chronic Ankle Instability

Background Researches have proved that deficits in ankle strength do not correlate highly with chronic ankle instability (CAI) and muscular weakness exists at proximal joints in these individuals. As strength deficits can lead to functional limitations, this study aimed to find if there is any correlation between the isometric strength of abductors and extensors of the hip and flexors and extensors of the knee of the involved side in subjects with unilateral CAI with the Foot and Ankle Disability Index (FADI) score. Methods 30 subjects with unilateral CAI took part. FADI score (expressed as percentage) and isometric strength was obtained for aforementioned muscles using a strain gauge. Results There existed no correlation between the strength measures and FADI score. Conclusion Clinicians must assess both functional limitations and strength of proximal muscles separately as they do not correlate with each other.