THE BIOMECHANICAL DIFFERENCES IN TURNING GAIT WITH AND WITHOUT ANKLE BRACE

Clinical management of ankle injuries often involves use of braces to provide pain relief and stability. Individuals with braced ankles may be at more risk of injury while turning. The aim of this study was to evaluate the biomechanical effects of one of the commonly prescribed pneumatic ankle braces on gait parameters while turning. Three-dimensional gait data was collected using a 7 camera, VICON 612 (Oxford Metric, UK) motion analysis system (120 HZ) synchronised with a single Kistler force plate embedded in the floor and set at a sampling frequency of 600HZ. Sixteen retro-reflective markers were attached to anatomical landmarks on both lower limbs and pelvis using wig tape. In the case of the braced ankle, markers were attached on the brace over the respective body landmarks. Out of ten trials, five were performed with and the other five without brace. Comparative results were produced between braced and un-braced ankle during turning at 90 degrees with the right foot landing on the force plate and turning right. Results show that use of brace is effective in reducing gross moments about the ankle joint even at the time of turning but it does not totally eliminate motion. Both conditions showed different rotation moments at knee but hip rotation moments were not affected by the brace. Knee rotation moment without brace was mainly in internal rotation (0.301Nm/kg) towards the terminal stance phase and it reduced to 0.128Nm/kg by bracing the ankle. A new type of turning strategy was identified where the subject pre-planned the turn in late swing phase before landing on the ground probably to avoid a fall. It is important that patients with ankle injuries receive supervised gait training to improve their turning confidence during their rehabilitation therapy.