Ankle bracing alters knee and ankle kinematics but not ground reaction forces during a jump-landing

To evaluate the effects of prophylactic ankle bracing on lower extremity kinematics and kinetics during a jump-landing, an experimental research design was used to compare an intervention (n=21) and control (n=21) group in both braced and unbraced conditions. Forty-two healthy physically active subjects with stable ankles volunteered to participate. Knee and ankle kinematic and kinetic data were recorded. A mixed model multivariate analysis of variance was used for statistical analyses. During wearing of the ankle brace, there was a significant decrease in ankle dorsiflexion range of motion (P=.031) and an increase in knee flexion at initial ground contact (P=.0004). However, there were no changes in vertical ground reaction force during wearing of the ankle brace (P=.479). Prophylactic ankle bracing had no negative effect on knee and ankle kinematics or ground reaction forces, but may have beneficial effects in preventing ankle sprains and other lower extremity injuries.