title: The influence of experience on knee mechanics during side-step cutting in females.
abstract: BACKGROUND
  It is thought that female athletes with limited experience in a sport perform athletic maneuvers differently than their more experienced counterparts, and that they do so in a manner that places them at greater risk for injury. The purpose of this study was to evaluate the influence of athletic experience on knee mechanics during the execution of a side-step cutting maneuver in young female athletes.
  
  
  METHODS
  Three-dimensional kinematics, ground reaction forces and electromyographic activity (surface electrodes) were recorded during the early deceleration phase of side-step cutting in 30 high school females (15 experienced, 15 novice). Group differences in knee joint kinematics, peak moments, net joint moment impulse and average muscle activation were evaluated.
  
  
  RESULTS
  No significant group differences were found in knee kinematics. When compared to experienced females, novice females demonstrated significantly smaller flexor, adductor, and internal rotator peak moments and smaller net joint moment impulse in all three planes at the knee. No group differences were found for average EMG; however, novice athletes had significantly greater co-contraction at the knee.
  
  
  CONCLUSIONS
  The finding of smaller knee moments and greater muscle co-contraction in the novice group suggests that these athletes may adopt a protective strategy in response to a relatively unfamiliar task. In addition, these results suggest that increased moments at the knee emerge with experience, indicating that more skilled athletes may be at greater risk for anterior cruciate ligament (ACL) injury.
authors: Musculoskeletal Biomechanics Research Laboratory, Department of Biokinesiology and Physical Therapy, University of Southern California, Los Angeles, CA 90089, USA. sigward@usc.edu
authors: Susan
authors: S
authors: Sigward
authors: Christopher M
authors: CM
authors: Powers