The Impact of Unilateral Versus Bilateral Ankle Bracing on Kinematics, Kinetics, and Performance in Volleyball Players

Abstract

This study examined the effect of different types of ankle braces (Ankle Stabilizing Orthosis (ASO) vs. T2 Active Ankle(T2)) when worn unilaterally (UNI), bilaterally (BI), and with no brace worn (UB) on lower extremity kinematics and kinetics during a vertical jump and agility test. Twenty-two competitive volleyball players completed both a vertical jump test and agility T-test under five bracing conditions. Vertical jump height (VJH), ankle dorsiflexion (ADF), ankle plantarflexion (APF), knee flexion (KF), hip flexion (HF), vertical ground reaction force (vGRF), and vertical impulse were measured during the vertical jump test, while time to completion was measured for the agility T-Test. There were no significant interaction effects between the types of ankle brace and bracing conditions for VJH and agility time. Significant main effects were found, however, for bracing conditions in VJH (p<.001) and agility time (p=.007) with decreased performance seen for both UNI and BI bracing compared to UB. The results also revealed significant interaction effects between types of brace and bracing conditions for both the ADF (p=.003) and APF angles (p=.004). When examining the interactions, the ASO brace resulted in lower ADF and APF angle than the T2 brace for the UNI and BI conditions. The results suggest that wearing ankle braces may reduce vertical jump and agility performance, however, there were little differences between the UNI and BI conditions. KEY WORDS: Ankle bracing, kinematics, kinetics, vertical jump, agility performance