title: Abnormal frontal plane knee mechanics during sidestep cutting in female soccer athletes after anterior cruciate ligament reconstruction and return to sport.
abstract: BACKGROUND
  Athletes who have undergone anterior cruciate ligament reconstruction (ACLR) have a high risk of reinjury upon the return to sports participation. While the mechanisms behind this increased risk of reinjury are unknown, it has been suggested that altered knee biomechanics during sports-specific activities may be a contributing factor. Purpose/
  
  
  OBJECTIVE
  To compare frontal plane knee joint angles and moments during a sidestep cutting maneuver in female soccer athletes who have undergone ACLR with those in athletes with no history of knee injury. It was hypothesized that athletes with a history of ACLR would exhibit increased knee abduction angles and knee adductor moments compared with those with no history of injury.
  
  
  METHODS
  Controlled laboratory study.
  
  
  METHODS
  Twelve female soccer players with a history of ACLR served as the experimental group, and 12 female soccer players with no history of knee injury constituted the control group. Three-dimensional kinematics and ground-reaction forces were collected while each participant performed a sidestep cutting maneuver. Variables of interest included the knee abduction angle and knee adductor moment during the early deceleration phase of the cutting maneuver. Independent-samples t tests were used to evaluate differences between groups (P ≤ .05).
  
  
  RESULTS
  Participants in the ACLR group exhibited increased average knee abduction angles (ACLR: 3.8° vs control: 1.8°; P = .03) and peak knee adductor moments (ACLR: 1.33 N·m/kg vs control: 0.80 N·m/kg; P = .004) compared with the control group.
  
  
  CONCLUSIONS
  Female soccer players who have undergone ACLR and returned to sports participation exhibited increased knee abduction angles and knee adductor moments during the early deceleration phase of cutting compared with their healthy counterparts with no history of knee injury.
  
  
  CONCLUSIONS
  Even though athletes are able to return to sport after ACLR, they are at an increased risk for reinjury. It may be the case that the increased frontal plane knee angles and moments exhibited by these athletes after ACLR could be contributing to this risk for reinjury. Therefore, it is important that rehabilitation programs after ACLR include the restoration of frontal plane knee mechanics.
authors: Division of Biokinesiology and Physical Therapy, University of Southern California, Los Angeles, CA, USA.
authors: Kristen M
authors: KM
authors: Stearns
authors: Christine D
authors: CD
authors: Pollard
mesh_terms: D000328:Adult; D016118:Anterior Cruciate Ligament / Q000601:surgery; D000070598:Anterior Cruciate Ligament Injuries; D059549:Anterior Cruciate Ligament Reconstruction; D001696:Biomechanical Phenomena; D005260:Female; D006801:Humans; D007718:Knee Injuries / Q000503:physiopathology* / Q000534:rehabilitation / Q000601:surgery; D007719:Knee Joint / Q000502:physiology*; D012916:Soccer / Q000293:injuries / Q000502:physiology*; D055815:Young Adult