Background In handball an anterior cruciate ligament injury often occurs during a jump shot landing. Video feedback is effective to improve landing although little is known about its influence in sport-specific movements.
Objective Test effectiveness of video overlay feedback on landing technique.
Design Randomized controlled trial.
Setting Controlled laboratory with elite athletes.
Participants Sixteen female handball players were randomly assigned to a Control (CG) or Video (VG) Group.
Interventions Both groups performed jump shots in pre-test (5 trials), two training sessions (TR1 & TR2, 2x10 trials) and post-test (5 trials). In TR1 and TR2, the VG received self-controlled video feedback of an expert model with an overlay of their own jump shots.
Main Outcome Measurements Knee and hip flexion angles (initial contact (IC), maximum (MAX) and range of motion (ROM)). Landing Error Scoring System (LESS) score. Shot accuracy, jump height and distance to assess performance.
Results From pre- to post-test, knee (pre-test IC: −12.4°±3.9, post-test IC: −17.3°±2.4, pre-test MAX: −70.4°±2.8, post-test MAX: −99.6°±11.3, pre-test ROM: −58.1°±5.3, post-test ROM: −82.3°±10.5) and hip (pre-test IC: 29.7°±4.4, post-test IC: 38.7°±6.4, pre-test MAX: 58.9°±11.4, post-test MAX: 97.8°±17.6, pre-test ROM: 31.6°±12.5, post-test ROM: 63.9°±11.7) flexion improved in the VG (p<0.05). The VG reduced their LESS score (pre-test 8.1, post-test 4.0; p<0.05). CG did not show significant changes, resulting in group*time interaction effects for mentioned variables (p<0.05). No differences were found in shot accuracy and jump height, whilst jump distance increased at post-test in the VG.
Conclusions Overlay visual feedback is effective to improve landing technique during a jump shot whilst maintaining performance. For enhancing injury prevention, it is imperative to determine long-term effects and transfer to training and game situations.