title: Anterior cruciate ligament injury alters preinjury lower extremity biomechanics in the injured and uninjured leg: the JUMP-ACL study.
abstract: BACKGROUND
  Information as to how anterior cruciate ligament (ACL) injury and reconstructive surgery (ACLR) alter lower extremity biomechanics may improve rehabilitation and return to play guidelines, reducing the risk for repeat ACL injury.
  
  
  OBJECTIVE
  To compare lower extremity biomechanics before ACL injury and after subsequent ACLR for the injured and uninjured leg.
  
  
  METHODS
  Baseline unilateral lower extremity biomechanics were collected on the dominant leg of participants without ACL injury when they entered the Joint Undertaking to Monitor and Prevent ACL (JUMP-ACL) study. Thirty-one participants with subsequent ACL injury, reconstructive surgery and full return to physical activity completed repeat, follow-up biomechanical testing, as did 39 uninjured, matched controls. Not all injured participants suffered injury to the dominant leg, requiring separation of those with ACL injury into two groups: ACLR-injured leg group (n=12) and ACLR-uninjured leg group (n=19). We compared the landing biomechanics of these three groups (ACLR-injured leg, ACLR-uninjured leg, control) before ACL injury (baseline) with biomechanics after ACL injury, surgery and return to physical activity (follow-up).
  
  
  RESULTS
  ACL injury and ACLR altered lower extremity biomechanics, as both ACLR groups demonstrated increases in frontal plane movement (increased hip adduction and knee valgus). The ACLR-injured leg group also exhibited decreased sagittal plane loading (decreased anterior tibial shear force, knee extension moment and hip flexion moment). No high-risk biomechanical changes were observed in control group participants.
  
  
  CONCLUSIONS
  ACL injury and ACLR caused movement pattern alterations of the injured and uninjured leg that have previously shown to increase the risk for future non-contact ACL injury.
authors.affiliation: Department of Kinesiology and Health, Georgia State University, Atlanta, Georgia, USA.
authors.forename: Benjamin M
authors.initials: BM
authors.lastname: Goerger
authors.affiliation: Department of Epidemiology, The University of North Carolina, Chapel Hill, North Carolina, USA.
authors.forename: Stephen W
authors.initials: SW
authors.lastname: Marshall
authors.affiliation: Department of Family Medicine, Uniformed Services University of the Health Sciences, Bethesda, Maryland, USA.
authors.forename: Anthony I
authors.initials: AI
authors.lastname: Beutler
authors.affiliation: Department of Exercise and Sport Science, The University of North Carolina, Chapel Hill, North Carolina, USA.
authors.forename: J Troy
authors.initials: JT
authors.lastname: Blackburn
authors.affiliation: Department of Orthopaedic Surgery, Johns Hopkins University, Baltimore, Maryland, USA.
authors.forename: John H
authors.initials: JH
authors.lastname: Wilckens
authors.affiliation: Department of Exercise and Sport Science, The University of North Carolina, Chapel Hill, North Carolina, USA.
authors.forename: Darin A
authors.initials: DA
authors.lastname: Padua
mesh_terms: D000070598:Anterior Cruciate Ligament Injuries; D001265:Athletic Injuries / Q000503:physiopathology*; D001696:Biomechanical Phenomena; D016022:Case-Control Studies; D005260:Female; D006621:Hip Joint / Q000502:physiology; D006801:Humans; D007719:Knee Joint / Q000502:physiology; D007866:Leg / Q000502:physiology; D007869:Leg Injuries / Q000503:physiopathology*; D009068:Movement / Q000502:physiology; D011446:Prospective Studies; D055815:Young Adult
keywords: ACL; Biomechanics; Knee injuries