title: Landing Technique and Performance in Youth Athletes After a Single Injury-Prevention Program Session.
abstract: BACKGROUND
  Injury-prevention programs (IPPs) performed as season-long warm-ups improve injury rates, performance outcomes, and jump-landing technique. However, concerns regarding program adoption exist. Identifying the acute benefits of using an IPP compared with other warm-ups may encourage IPP adoption.
  
  
  OBJECTIVE
  To examine the immediate effects of 3 warm-up protocols (IPP, static warm-up [SWU], or dynamic warm-up [DWU]) on jump-landing technique and performance measures in youth athletes.
  
  
  METHODS
  Randomized controlled clinical trial.
  
  
  METHODS
  Gymnasiums.
  
  
  METHODS
  Sixty male and 29 female athletes (age = 13 ± 2 years, height = 162.8 ± 12.6 cm, mass = 37.1 ± 13.5 kg) volunteered to participate in a single session.
  
  
  METHODS
  Participants were stratified by age, sex, and sport and then were randomized into 1 protocol: IPP, SWU, or DWU. The IPP consisted of dynamic flexibility, strengthening, plyometric, and balance exercises and emphasized proper technique. The SWU consisted of jogging and lower extremity static stretching. The DWU consisted of dynamic lower extremity flexibility exercises. Participants were assessed for landing technique and performance measures immediately before (PRE) and after (POST) completing their warm-ups.
  
  
  METHODS
  One rater graded each jump-landing trial using the Landing Error Scoring System. Participants performed a vertical jump, long jump, shuttle run, and jump-landing task in randomized order. The averages of all jump-landing trials and performance variables were used to calculate 1 composite score for each variable at PRE and POST. Change scores were calculated (POST - PRE) for all measures. Separate 1-way (group) analyses of variance were conducted for each dependent variable (α < .05).
  
  
  RESULTS
  No differences were observed among groups for any performance measures (P > .05). The Landing Error Scoring System scores improved after the IPP (change = -0.40 ± 1.24 errors) compared with the DWU (0.27 ± 1.09 errors) and SWU (0.43 ± 1.35 errors; P = .04).
  
  
  CONCLUSIONS
  An IPP did not impair sport performance and may have reduced injury risk, which supports the use of these programs before sport activity.
authors.affiliation: Department of Kinesiology, University of Connecticut, Storrs.
authors.forename: Hayley
authors.initials: H
authors.lastname: Root
authors.affiliation: Department of Kinesiology, University of Connecticut, Storrs.
authors.forename: Thomas
authors.initials: T
authors.lastname: Trojian
authors.affiliation: Department of Kinesiology, University of Connecticut, Storrs.
authors.forename: Jessica
authors.initials: J
authors.lastname: Martinez
authors.affiliation: Department of Kinesiology, University of Connecticut, Storrs.
authors.forename: William
authors.initials: W
authors.lastname: Kraemer
authors.affiliation: Department of Kinesiology, University of Connecticut, Storrs.
authors.forename: Lindsay J
authors.initials: LJ
authors.lastname: DiStefano
mesh_terms: D000293:Adolescent; D016118:Anterior Cruciate Ligament / Q000502:physiology; D000070598:Anterior Cruciate Ligament Injuries; D001265:Athletic Injuries / Q000503:physiopathology / Q000517:prevention & control*; D054874:Athletic Performance; D005081:Exercise Therapy / Q000379:methods*; D005260:Female; D006801:Humans; D035002:Lower Extremity / Q000502:physiology*; D008297:Male; D013177:Sports / Q000502:physiology; D063996:Warm-Up Exercise / Q000502:physiology*
keywords: anterior cruciate ligament; injury risk; knee