title: Anterior cruciate ligament (ACL) loading in a collegiate athlete during sidestep cutting after ACL reconstruction: A case study.
abstract: BACKGROUND
  Athletes with anterior cruciate ligament (ACL) injuries usually undergo ACL-reconstruction (ACLR) in order to restore joint stability, so that dynamic maneuvers such as the sidestep cut can be performed. Despite restoration of joint stability after ACLR, many athletes do not return to pre-injury levels and may be at a high risk of a second ACL injury. The purpose of this study was to determine whether or not ACL loading, would increase after ACLR.
  
  
  METHODS
  One female Division I collegiate athlete performed bilateral unanticipated sidestep cuts both before ACL injury and 27months after ACLR. Musculoskeletal simulations were used to calculate ACL loading during the deceleration phase of the sidestep cuts.
  
  
  RESULTS
  Twenty-seven months after ACLR, the athlete demonstrated higher total ACL loading in the ipsilateral limb as well as altered joint kinematics, moments, and quadriceps muscle force production. In the contralateral limb, there were no increases in total ACL loading or muscle force production yet altered lower extremity joint kinematics and moments were present after ACLR.
  
  
  CONCLUSIONS
  Higher total ACL loading in the ipsilateral limb of this athlete may suggest an increased risk of second ACL injury. The results of this study provide an initial step in understanding the effects of ACLR on the risk of second ACL injury in an elite athlete and suggest that it is important to develop a better understanding of this surgical intervention on knee joint loading, in order to reduce the risk of second ACL injury while performing dynamic maneuvers.
authors.affiliation: Department of Mechanical and Aerospace Engineering, Old Dominion University, 238 Kaufman Hall, Norfolk, VA 23529, USA; Department of Radiology and Biomedical Imaging, University of California, San Francisco, 185 Berry Street, Lobby 6, Suite 350, San Francisco, CA 94107, USA. Electronic address: michael.samaan@ucsf.edu.
authors.forename: Michael A
authors.initials: MA
authors.lastname: Samaan
authors.affiliation: Department of Mechanical and Aerospace Engineering, Old Dominion University, 238 Kaufman Hall, Norfolk, VA 23529, USA.
authors.forename: Stacie I
authors.initials: SI
authors.lastname: Ringleb
authors.affiliation: Department of Mechanical and Aerospace Engineering, Old Dominion University, 238 Kaufman Hall, Norfolk, VA 23529, USA.
authors.forename: Sebastian Y
authors.initials: SY
authors.lastname: Bawab
authors.affiliation: Department of Exercise Science and Community Health, University of West Florida, 11000 University Pkwy., Bldg. 72, Rm. 216, Pensacola, FL 32514, USA.
authors.forename: Eric K
authors.initials: EK
authors.lastname: Greska
authors.affiliation: Department of Kinesiology, Recreation and Sports Studies, The University of Tennessee, 333 HPER Building, 1914 Andy Holt Avenue, Knoxville, TN 37996, USA.
authors.forename: Joshua T
authors.initials: JT
authors.lastname: Weinhandl
mesh_terms: D016118:Anterior Cruciate Ligament / Q000503:physiopathology* / Q000601:surgery; D000070598:Anterior Cruciate Ligament Injuries / Q000503:physiopathology* / Q000601:surgery; D059549:Anterior Cruciate Ligament Reconstruction / Q000379:methods*; D001265:Athletic Injuries / Q000503:physiopathology* / Q000601:surgery; D001696:Biomechanical Phenomena; D005260:Female; D006801:Humans; D007593:Joint Instability / Q000503:physiopathology* / Q000601:surgery; D052097:Quadriceps Muscle / Q000503:physiopathology*; D016059:Range of Motion, Articular; D055815:Young Adult
keywords: ACL loading; ACL reconstruction; Anterior cruciate ligament; Musculoskeletal modeling; OpenSim; Sidestep cutting