Hop-Stabilization Training and Landing Biomechanics in Athletes With Chronic Ankle Instability: A Randomized Controlled Trial

Context: Hopping exercises are recommended as a functional training tool to prevent lower limb injury, but their effects on lower extremity biomechanics in those with chronic ankle instability (CAI) are unclear. Objective: To determine if jump-landing biomechanics change after a hop-stabilization intervention. Design: Randomized controlled clinical trial. Setting: Research laboratory. Patients or Other Participants: Twenty-eight male collegiate basketball players with CAI were divided into 2 groups: hop-training group (age = 22.78 +/- 3.09 years, mass = 82.59 +/- 9.51 kg, height = 187.96 +/- 7.93 cm) and control group (age = 22.57 +/- 2.76 years, mass = 78.35 +/- 7.02 kg, height = 185.69 +/- 7.28 cm). Intervention(s): A 6-week supervised hop-stabilization training program that consisted of 18 training sessions. Main Outcome Measure(s): Lower extremity kinetics and kinematics during a jump-landing task and self-reported function were assessed before and after the 6-week training program. Results: The hop-stabilization program resulted in improved self-reported function (P < .05), larger sagittal-plane hip- and knee-flexion angles, and greater ankle dorsiflexion (P < .05) relative to the control group. Reduced frontal-plane joint angles at the hip, knee, and ankle as well as decreased ground reaction forces and a longer time to peak ground reaction forces were observed in the hopping group compared with the control group after the intervention (P < .05). Conclusions: The 6-week hop-stabilization training program altered jump-landing biomechanics in male collegiate basketball players with CAI. These results may provide a potential mechanistic explanation for improvements in patient-reported outcomes and reductions in injury risk after ankle-sprain rehabilitation programs that incorporate hop-stabilization exercises.