Lower limb joint motion during a cross cutting movement differs in individuals with and without chronic ankle instability.

OBJECTIVE To compare the kinematics of lower limb joints between individuals with and without chronic ankle instability (CAI) during cross-turn and -cutting movements. DESIGN Cross-sectional study. SETTING Motion analysis laboratory. PARTICIPANTS Twelve subjects with CAI and twelve healthy controls. MAIN OUTCOME MEASURES Hip flexion, adduction, and internal rotation, knee flexion, and ankle dorsiflexion and inversion angles were calculated in the 200 ms before initial ground contact and from initial ground contact to toe-off (stance phase) in a cross-turn movement during gait and a cross-cutting movement from a forward jump, and compared across the two groups. RESULTS In the cross-cutting movement, the CAI group exhibited greater hip and knee flexion than the control group during the stance phase, and more hip abduction during the period before initial contact and the stance phase. In the cross-turn movement the joint kinematics were similar in the two groups. CONCLUSIONS CAI subjects exhibited an altered pattern of the proximal joint kinematics during a cross-cutting movement. It is important for clinicians to assess the function of the hip and knee as well as the ankle, and to incorporate coordination training for the entire lower limb into rehabilitation after lateral ankle sprains.