title: Jump-landing biomechanics following a 4-week real-time feedback intervention and retention.
abstract: BACKGROUND
  Poor neuromuscular control can increase the risk of anterior cruciate ligament (ACL) injury. Landing with decreased knee and hip flexion may increase the risk of lower extremity injury. Feedback interventions have demonstrated changes in jump-landing biomechanics. Traditional feedback (TF), provided after task completion, includes critical factors to focus on during jump-landing. Real-time feedback (RTF), provided while completing the task, may be superior for improving jump-landing biomechanics. This investigation evaluated the effect of RTF+TF compared to TF and a control group in changing lower extremity jump-landing biomechanics following a 4-week feedback intervention and a 1-week no feedback retention.
  
  
  METHODS
  Participants completed 12 feedback sessions over 4 weeks. At each session, participants performed 6 sets of 6 jumps off a 30 cm box. Participants were provided TF or RTF+TF following each set of jumps. Participants were tested at baseline, immediately following the 4-week intervention and following a 1-week retention. The control group was tested at two time points 4 weeks apart.
  
  
  RESULTS
  Acquisition analysis: RTF+TF and TF groups demonstrated greater change in peak hip flexion angles and peak knee flexion angles compared to the control group following the intervention. TF and RTF+TF groups demonstrated a greater decrease in peak vertical ground reaction force compared to the control group. No significant differences were observed between groups in the retention analysis.
  
  
  CONCLUSIONS
  This study provides evidence of acquisition of biomechanical changes following a 4-week feedback intervention. Future research should further investigate the retention of biomechanical changes, the optimal length of feedback interventions and transfer of learned biomechanics to similar athletic tasks.
authors: Northern Kentucky University, Highland Heights, KY, USA. Electronic address: ericksenh1@nku.edu.
authors: Hayley M
authors: HM
authors: Ericksen
authors: University of North Carolina at Charlotte, Charlotte, NC, USA.
authors: Abbey C
authors: AC
authors: Thomas
authors: University of Kentucky, Lexington, KY, USA.
authors: Phillip A
authors: PA
authors: Gribble
authors: University of Toledo, Toledo, OH, USA.
authors: Charles
authors: C
authors: Armstrong
authors: University of Toledo, Toledo, OH, USA.
authors: Martin
authors: M
authors: Rice
authors: Department of Exercise and Sport Science, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
authors: Brian
authors: B
authors: Pietrosimone
mesh_terms: D000293:Adolescent; D000328:Adult; D000070598:Anterior Cruciate Ligament Injuries; D059549:Anterior Cruciate Ligament Reconstruction / Q000379:methods*; D001696:Biomechanical Phenomena; D015444:Exercise; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D007718:Knee Injuries / Q000534:rehabilitation* / Q000601:surgery*; D007719:Knee Joint / Q000503:physiopathology; D008297:Male; D015999:Multivariate Analysis; D055815:Young Adult
keywords: ACL injury; Augmented feedback; Injury risk; Prevention