title: Different exercise training interventions and drop-landing biomechanics in high school female athletes.
abstract: BACKGROUND
  Anterior cruciate ligament (ACL) injuries are common in female athletes and are related to poor neuromuscular control. Comprehensive neuromuscular training has been shown to improve biomechanics; however, we do not know which component of neuromuscular training is most responsible for the changes.
  
  
  OBJECTIVE
  To assess the efficacy of either a 4-week core stability program or plyometric program in altering lower extremity and trunk biomechanics during a drop vertical jump (DVJ).
  
  
  METHODS
  Cohort study.
  
  
  METHODS
  High school athletic fields and motion analysis laboratory.
  
  
  METHODS
  Twenty-three high school female athletes (age = 14.8 ± 0.8 years, height = 1.7 ± 0.07 m, mass = 57.7 ± 8.5 kg).
  
  
  METHODS
  Independent variables were group (core stability, plyometric, control) and time (pretest, posttest). Participants performed 5 DVJs at pretest and posttest. Intervention participants engaged in a 4-week core stability or plyometric program.
  
  
  METHODS
  Dependent variables were 3-dimensional hip, knee, and trunk kinetics and kinematics during the landing phase of a DVJ. We calculated the group means and associated 95% confidence intervals for the first 25% of landing. Cohen d effect sizes with 95% confidence intervals were calculated for all differences.
  
  
  RESULTS
  We found within-group differences for lower extremity biomechanics for both intervention groups (P ≤ .05). The plyometric group decreased the knee-flexion and knee internal-rotation angles and the knee-flexion and knee-abduction moments. The core stability group decreased the knee-flexion and knee internal-rotation angles and the hip-flexion and hip internal-rotation moments. The control group decreased the knee external-rotation moment. All kinetic changes had a strong effect size (Cohen d > 0.80).
  
  
  CONCLUSIONS
  Both programs resulted in biomechanical changes, suggesting that both types of exercises are warranted for ACL injury prevention and should be implemented by trained professionals.
authors.affiliation: College of Charleston, 66 George Street, Charleston, SC 29424, USA. pfilekr@cofc.edu
authors.forename: Kate R
authors.initials: KR
authors.lastname: Pfile
authors.forename: Joseph M
authors.initials: JM
authors.lastname: Hart
authors.forename: Daniel C
authors.initials: DC
authors.lastname: Herman
authors.forename: Jay
authors.initials: J
authors.lastname: Hertel
authors.forename: D Casey
authors.initials: DC
authors.lastname: Kerrigan
authors.forename: Christopher D
authors.initials: CD
authors.lastname: Ingersoll
mesh_terms: D000293:Adolescent; D056352:Athletes; D001696:Biomechanical Phenomena; D005260:Female; D006801:Humans; D007718:Knee Injuries / Q000517:prevention & control; D007719:Knee Joint / Q000502:physiology*; D009068:Movement / Q000502:physiology*; D010806:Physical Education and Training / Q000379:methods*; D011434:Proprioception / Q000502:physiology*; D012399:Rotation