Can the hamstring muscles protect the anterior cruciate ligament during a side-cutting maneuver?
Because anterior cruciate ligament (ACL) injuries are common in European handball the present study assessed knee joint shear forces to estimate ACL loading in six elite female handball players during a side-cutting maneuver. A pilot investigation in three dimensions showed that peak moments occurred in the sagittal plane at a high velocity. Therefore, analysis of the movement was performed in two dimensions using high-speed cinematography, ground reaction forces, and electromyography (EMG). Film and force plate data allowed for calculation of net joint moments (inverse dynamics), estimates of instantaneous muscle-tendon lengths, contraction velocities, and peak loading of the ACL. During the breaking phase of the maneuver the peak knee joint moment was 239 Nm (99-309), which yielded an ACL-load of 520 N (215-673). The corresponding peak EMG amplitudes for the hamstring muscles were 34-39% of maximum EMG. During the breaking phase the quadriceps muscle contracted eccentrically with a v
