Real-time feedback during drop landing training improves subsequent frontal and sagittal plane knee kinematics.

Background: Although neuromuscular training featuring visual feedback may benefit modification of anterior cruciate ligament injury-risk linked knee kinematics, wide-spread clinical intervention has been limited to date. This study evaluated the effects of a Microsoft Kinect-based feedback system for modification of drop vertical jump knee kinematics traditionally consistent with predisposition to non-contact anterior cruciate ligament injury in female athletes. We hypothesized that a four-week feedback training protocol would increase peak knee flexion angle and frontal plane valgus-correlated knee separation distance during drop jump landing performance.

Methods: Twenty-four female athletes were randomly divided equally into control or Kinect-based feedback groups. Subjects were pre-screened for peak knee flexion angle and minimum knee separation distance during drop landing and later performed twenty 31cm drop landings three days per week for four weeks. The feedback group received Kinect-based visual feedback, while controls did not. Kinematics were re-assessed immediately following the end of the training period.

Findings: The feedback group increased peak knee flexion and experienced a greater improvement in peak knee flexion. The feedback group improved normalized knee separation distance with greater improvement in post-training peak knee separation distance as compared with controls.

Interpretation: Kinect-based feedback training significantly improved drop vertical jump knee kinematics associated with non-contact anterior cruciate ligament injury. The Kinect-based feedback approach demonstrates promise for mitigating non-contact anterior cruciate ligament injury predisposing knee biomechanics in female athletes within the clinical environment.