title: Instruction of jump-landing technique using videotape feedback: altering lower extremity motion patterns.
abstract: BACKGROUND
  Anterior cruciate ligament injury prevention programs have used videotapes of jump-landing technique as a key instructional component to improve landing performance.
  
  
  OBJECTIVE
  All videotape feedback model groups will increase knee flexion angles at initial contact and overall knee flexion motion and decrease peak vertical ground reaction forces and peak proximal anterior tibial shear forces to a greater extent than will a nonfeedback group. The secondary hypothesis is that the videotape feedback using the combination of the expert and self models will create the greatest change in each variable.
  
  
  METHODS
  Controlled laboratory study.
  
  
  METHODS
  Knee kinematics and kinetics of college-aged recreational athletes randomly placed in 3 different videotape feedback model groups (expert only, self only, combination of expert and self) and a nonfeedback group were collected while participants performed a basketball jump-landing task on 3 testing occasions.
  
  
  RESULTS
  All feedback groups significantly increased knee angular displacement flexion angles [F(6,70) = 8.03, P = .001] and decreased peak vertical ground reaction forces [F(6,78) = 2.68, P = .021] during performance and retention tests. The self and combination groups significantly increased knee angular displacement flexion angles more than the control group did; the expert model group did not change significantly more than the control group did. All feedback groups and the nonfeedback group significantly reduced peak vertical forces across performance and retention tests. There were no statistically significant changes in knee flexion angle at initial ground contact (P = .111) and peak proximal anterior tibial shear forces (P = .509) for both testing sessions for each group.
  
  
  CONCLUSIONS
  The use of self or combination videotape feedback is most useful for increasing knee angular displacement flexion angles and reducing peak vertical forces during landing.
  
  
  CONCLUSIONS
  The use of self or combination modeling is more effective than is expert-only modeling for the implementation of instructional programs aimed at reducing the risk of jump-landing anterior cruciate ligament injuries.
authors.affiliation: University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA. jonate@odu.edu
authors.forename: James A
authors.initials: JA
authors.lastname: Oñate
authors.forename: Kevin M
authors.initials: KM
authors.lastname: Guskiewicz
authors.forename: Stephen W
authors.initials: SW
authors.lastname: Marshall
authors.forename: Carol
authors.initials: C
authors.lastname: Giuliani
authors.forename: Bing
authors.initials: B
authors.lastname: Yu
authors.forename: William E
authors.initials: WE
authors.lastname: Garrett
mesh_terms: D000293:Adolescent; D000328:Adult; D000070598:Anterior Cruciate Ligament Injuries; D001696:Biomechanical Phenomena; D005246:Feedback; D006801:Humans; D035002:Lower Extremity / Q000502:physiology*; D009657:North Carolina; D011597:Psychomotor Performance; D014743:Videotape Recording; D014947:Wounds and Injuries / Q000517:prevention & control