Isometric Hip Strength and Patient-Reported Outcomes of Individuals With and Without Chronic Ankle Instability

Context: Strength deficits and decreased scores on generic, dimension-specific, and region-specific health-related quality of life (HRQL) PRO measures are commonly documented among individuals with chronic ankle instability (CAI). However, it is unknown if there is a relationship between hip strength and self-reported patient-reported outcome (PRO) scores. Objective: To compare isometric peak torque for hip-extension (H-EXT) and hip-abduction (H-ABD), as well as PRO scores between CAI, lateral ankle sprain copers (LAS copers), and uninjured controls (UC). The secondary purpose was to examine the relationship between isometric hip peak torque and PROs in participants with CAI. Design: Cross-sectional. Setting: Laboratory. Participants: Sixty-three individuals, 45 women (23.02 [3.83] y, 165.91 [7.55] cm, 67.28 [11.95] kg) and 18 men (26.28 [5.43] y, 179.28 [9.01] cm, 83.87 [13.26] kg), grouped as uninjured control (n = 26), LAS coper (n = 15), or CAI (n = 22). Main Outcome Measures: The Foot and Ankle Ability Measure was used to assess region-specific HRQL. The Fear Avoidance Beliefs Questionnaire was used to assess injury-related fear. The Disablement in Physically Active was used to assess global HRQL. Isometric peak torque was measured with a handheld dynamometer for H-EXT and H-ABD. Results: No group differences were observed for H-ABD (P = .34) or H-EXT (P = .35). The CAI group had significantly worse scores on all PROs compared with LAS coper (P < .001) and HC (P < .001). Moderate-weak correlations were found between H-ABD and Foot and Ankle Ability Measure-activities of daily living (P = .047; ρ = .392) and Foot and Ankle Ability Measure-Sport (P = .013; ρ = .482) and H- EXT and Fear Avoidance Beliefs Questionnaire-Work (P = .007; ρ = −.517). Conclusions: Individuals with CAI displayed lower HRQL based on worse scores on generic, dimension-specific, and region-specific PROs compared with LAS copers and uninjured controls. There were no significant between-group differences for H-EXT and H-ABD isometric peak torque production, but there was a moderate positive relationship between isometric H-ABD and self-reported ankle disability in individuals with CAI.