title: Predictors of Frontal Plane Knee Moments During Side-Step Cutting to 45 and 110 Degrees in Men and Women: Implications for Anterior Cruciate Ligament Injury.
abstract: OBJECTIVE
  To compare frontal plane knee moments, and kinematics and kinetics associated with knee valgus moments between cutting to 45 and 110 degrees, and to determine the predictive value of kinematics and ground reaction forces (GRFs) on knee valgus moments when cutting to these angles. Also, to determine whether sex differences exist in kinematics and kinetics when cutting to 45 and 110 degrees.
  
  
  METHODS
  Cross-sectional study.
  
  
  METHODS
  Laboratory setting.
  
  
  METHODS
  Forty-five (20 females) healthy young adult soccer athletes aged 16 to 23 years.
  
  
  METHODS
  Kinematic and kinetic variables were compared between randomly cued side-step cutting maneuvers to 45 and 110 degrees. Predictors of knee valgus moment were determined for each task.
  
  
  METHODS
  Kinematic variables: knee valgus angle, hip abduction, and internal rotation angles. Kinetic variables: vertical, posterior, and lateral GRFs, and knee valgus moment.
  
  
  RESULTS
  Knee valgus moments were greater when cutting to 110 degrees compared with 45 degrees, and females exhibited greater moments than males. Vertical and lateral GRFs, hip internal rotation angle, and knee valgus angle explained 63% of the variance in knee valgus moment during cutting to 45 degrees. During cutting to 110 degrees, posterior GRF, hip internal rotation angle, and knee valgus angle explained 41% of the variance in knee valgus moment.
  
  
  CONCLUSIONS
  Cutting tasks with larger redirection demands result in greater knee valgus moments. Similar factors, including shear GRFs, hip internal rotation, and knee valgus position contribute to knee valgus loading during cuts performed to smaller (45 degrees) and larger (110 degrees) angles.
  
  
  CONCLUSIONS
  Reducing vertical and shear GRFs during cutting maneuvers may reduce knee valgus moments and thereby potentially reduce risk for anterior cruciate ligament injury.
authors.affiliation: Human Performance Laboratory, Division of Biokinesiology and Physical Therapy, University of Southern California, Los Angeles, California.
authors.forename: Susan M
authors.initials: SM
authors.lastname: Sigward
authors.forename: Guilherme M
authors.initials: GM
authors.lastname: Cesar
authors.forename: Kathryn L
authors.initials: KL
authors.lastname: Havens
mesh_terms: D000293:Adolescent; D000070598:Anterior Cruciate Ligament Injuries; D001696:Biomechanical Phenomena; D003430:Cross-Sectional Studies; D005260:Female; D005544:Forecasting; D006801:Humans; D007718:Knee Injuries / Q000209:etiology*; D007719:Knee Joint / Q000502:physiology*; D008297:Male; D009068:Movement / Q000502:physiology*; D016059:Range of Motion, Articular / Q000502:physiology; D012737:Sex Factors; D012916:Soccer / Q000293:injuries / Q000502:physiology*; D017695:Soft Tissue Injuries / Q000209:etiology; D055815:Young Adult