SAGITTAL PLANE RESISTANCE TORQUE IN ANKLE BRACES

Abstract

Ligaments of the ankle joint complex are among the most frequently damaged structures during sports and physical activity (Eils et al., 2002). One common intervention used to prevent ankle ligament injury is the application of lace-up style ankle braces. These braces, usually made of non stretch nylon materials, increase the mechanical stability at the ankle joint by restricting the allowable range of motion thereby limiting strain on joint ligaments. Ankle braces are primarily designed to restrict motion in the frontal plane to limit ankle inversion and eversion without impeding the plantar-dorsi flexion (PF) motion (Eils et al., 2002). However, studies examining the effect of bracing on ankle motion during drop jumping have found a significant reduction in sagittal plane ankle motion while braced (DiStefano et al., 2008). Previous studies have examined isolated ankle range of motion restriction around the PF axis with different brace types (e.g. Eils et al 2002), but these studies were not able to distinguish the resistance torque due to the brace alone. The purpose of the present study was to measure the passive mechanical resistance torque around the ankle PF axis generated by a range of commercially available ankle braces while moving through the sagittal plane.