Bilateral ground reaction forces and joint moments for lateral sidestepping and crossover stepping tasks

Racquet sports have high levels of joint injuries suggesting thejoint loads during play may be excessive. sports such as badmintonemploy lateral sidestepping (ss) and crossover stepping(xs) movements which so far have not been described in termsof biomechanics. this study examined bilateral ground reactionforces and three dimensional joint kinetics for both these gaits inorder to determine the demands of the movements on the leadingand trailing limb and predict the contribution of thesemovements to the occurrence of overuse injury of the lowerlimbs. a force platform and motion-analysis system were usedto record ground reaction forces and track marker trajectories of9 experienced male badminton players performing lateral ss,xs and forward running tasks at a controlled speed of 3 m·s-1using their normal technique. ground reaction force and kineticdata for the hip, knee and ankle were analyzed, averaged acrossthe group and the biomechanical variables compared. in allcases the ground reaction forces and joint moments were lessthan those experienced during moderate running suggesting thatin normal play ss and xs gaits do not lead to high forces thatcould contribute to increased injury risk. ground reaction forcesduring ss and xs do not appear to contribute to the developmentof overuse injury. the distinct roles of the leading andtrailing limb, acting as a generator of vertical force and shockabsorber respectively, during the ss and xs may however contributeto the development of muscular imbalances which mayultimately contribute to the development of overuse injury.however it is still possible that faulty use of these gaits mightlead to high loads and this should be the subject of future work.