TY - JOUR T1 - Increased knee valgus alignment and moment during single-leg landing after overhead stroke as a potential risk factor of anterior cruciate ligament injury in badminton JF - British Journal of Sports Medicine JO - Br J Sports Med SP - 207 LP - 213 DO - 10.1136/bjsm.2010.080861 VL - 46 IS - 3 AU - Yuka Kimura AU - Yasuyuki Ishibashi AU - Eiichi Tsuda AU - Yuji Yamamoto AU - Yoshimitsu Hayashi AU - Shuichi Sato Y1 - 2012/03/01 UR - http://bjsm.bmj.com/content/46/3/207.abstract N2 - Background In badminton, knees opposite to the racket-hand side received anterior cruciate ligament (ACL) injuries during single-leg landing after overhead stroke. Most of them occurred in the backhand-side of the rear court. Comparing lower limb biomechanics during single-leg landing after overhead stroke between the forehand-side and backhand-side court may help explain the different injury rates depending on court position. Hypothesis The knee kinematics and kinetics during single-leg landing after overhead stroke following back-stepping were different between the forehand-side and backhand-side court. Study design Controlled laboratory study. Methods Hip, knee and ankle joint kinematic and knee kinetic data were collected for 17 right-handed female college badminton players using a 3-dimensional motion analysis system. Subjects performed single-left-legged landing after an overhead stroke following left and right back-stepping. The kinematic and kinetic data of the left lower extremities during landing were measured and compared between left and right back-steps. Results Hip flexion and abduction and knee valgus at the initial contact, hip and knee flexion and knee valgus at the maximum knee flexion and the maximum knee valgus moment were significantly larger for the left back-step than the right back-step (p<0.05). Conclusion Significant differences in joint kinematics and kinetics of the lower extremity during single-leg landing after overhead stroke were observed between different back-step directions. Increased knee valgus angle and moment following back-stepping to the backhand-side might be related to the higher incidence of ACL injury during single-leg landing after overhead stroke. ER -