title: Augmented feedback reduces jump landing forces.
abstract: METHODS
  Randomized, experimental design using a 1-way ANCOVA to determine the influence of various forms of feedback on jump landing forces.
  
  
  OBJECTIVE
  To investigate the effects of augmented feedback versus sensory feedback on the reduction of jump landing forces.
  
  
  BACKGROUND
  Several investigators have reported an increased risk of lower extremity injury associated with landing from a jump.
  
  
  METHODS
  Nonimpaired college students (N=63) were randomly assigned to 1 of 4 feedback groups. Subjects were instructed to perform maximal vertical jumps onto a force plate for 3 testing sessions (baseline, 2-minute post-test, and 1-week post-test). Three feedback groups (augmented, sensory, and control I) were tested during all 3 testing sessions, while a fourth feedback group (control II) was evaluated at only 2 sessions (baseline and 1-week post-test). Subjects in the augmented feedback condition were provided information via video and verbal analysis of how to land softer. Subjects in the sensory feedback condition were asked to use the experience of their baseline jumps to document how they could land softer. Subjects in each of the control groups were not provided any extraneous feedback. Peak vertical ground reaction force data were collected for analysis.
  
  
  RESULTS
  The subjects in the augmented feedback group significantly reduced their peak vertical ground reaction force in both post-test conditions (2-minute post-test reduction, 0.85+/-0.62; 1-week post-test reduction, 0.74+/-0.58) as compared to the sensory, control I, and control II feedback groups.
  
  
  CONCLUSIONS
  High impact landing forces may be reduced by the implementation of augmented feedback information instructing individuals about how to land properly. The reduction of jump landing forces with the use of augmented feedback may prove beneficial in the creation of instructional landing programs.
authors.affiliation: Department of Exercise and Sport Science, Human Movement Science Program, University of North Carolina at Chapel Hill, 27599-8700, USA. onatej@email.unc.edu
authors.forename: J A
authors.initials: JA
authors.lastname: Onate
authors.forename: K M
authors.initials: KM
authors.lastname: Guskiewicz
authors.forename: R J
authors.initials: RJ
authors.lastname: Sullivan
mesh_terms: D000222:Adaptation, Physiological / Q000502:physiology*; D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D001676:Biofeedback, Psychology / Q000379:methods* / Q000502:physiology*; D001696:Biomechanical Phenomena; D005260:Female; D006801:Humans; D008297:Male; D009068:Movement / Q000502:physiology; D011597:Psychomotor Performance / Q000502:physiology*; D011930:Reaction Time