title: Robotic simulation of identical athletic-task kinematics on cadaveric limbs exhibits a lack of differences in knee mechanics between contralateral pairs.
abstract: Limb asymmetry is a known factor for increased ACL injury risk. These asymmetries are normally observed during in vivo testing. Prior studies have developed in vitro testing methodologies driven by in vivo kinematics to investigate knee mechanics relative to ACL injury. The objective of this study was to determine if mechanical side-to-side asymmetries persist in contralateral pairs during in vitro simulation testing. In vivo kinematics were recorded for male and female drop vertical jump and sidestep cutting tasks. The recorded kinematics were used to robotically simulate the motions on 7 contralateral pairs of cadaveric lower extremities specimens. ACL and MCL force, torque, and strains were recorded and analyzed for differences between contralateral pairs. There was a general lack of mechanical differences between limb sides. Adduction peak torque for the male sidestep cut movement was significantly different between limb sides (p=0.04). However, this is consistent with ACL injury mechanics in that movement in the frontal plane (abduction/adduction) increases injury risk and it is possible loading differences in this plane may have resulted from tolerances within the setup process. The findings of this study indicate that contralateral knee joints were representative of each other during biomechanical in vitro tests. In future cadaveric robotic simulations, contralateral limbs can be used interchangeably. In addition, direct comparisons of the structural behaviors of isolated conditions for contralateral knee joints can be performed.
authors.affiliation: Department of Orthopedic Surgery, Mayo Clinic, Rochester, MN, USA; Department of Biomedical Engineering, University of Cincinnati, Cincinnati, OH, USA.
authors.forename: Nathaniel A
authors.initials: NA
authors.lastname: Bates
authors.affiliation: Department of Biomedical Engineering, University of Cincinnati, Cincinnati, OH, USA; Sports Medicine Biodynamics Center, Division of Sports Cincinnati Children׳s Hospital Medical Center, Cincinnati, OH, USA.
authors.forename: April L
authors.initials: AL
authors.lastname: McPherson
authors.affiliation: Department of Biomedical Engineering, University of Cincinnati, Cincinnati, OH, USA.
authors.forename: Rebecca J
authors.initials: RJ
authors.lastname: Nesbitt
authors.affiliation: Department of Biomedical Engineering, University of Cincinnati, Cincinnati, OH, USA.
authors.forename: Jason T
authors.initials: JT
authors.lastname: Shearn
authors.affiliation: Sports Medicine Biodynamics Center, Division of Sports Cincinnati Children׳s Hospital Medical Center, Cincinnati, OH, USA; Department of Pediatrics, College of Medicine, University of Cincinnati, Cincinnati, OH, USA; Department of Orthopaedic Surgery, College of Medicine, University of Cincinnati, Cincinnati, OH, USA; The Micheli Center for Sports Injury Prevention, Boston, MA, USA.
authors.forename: Gregory D
authors.initials: GD
authors.lastname: Myer
authors.affiliation: Department of Orthopedic Surgery, Mayo Clinic, Rochester, MN, USA; Department of Biomedical Engineering, University of Cincinnati, Cincinnati, OH, USA; Mayo Clinic Biomechanics Laboratories and Sports Medicine Center, Departments of Orthopedics, Physical Medicine and Rehabilitation and Physiology & Biomedical Engineering, Mayo Clinic, Rochester and Minneapolis, MN.. Electronic address: hewett.timothy@mayo.edu.
authors.forename: Timothy E
authors.initials: TE
authors.lastname: Hewett
mesh_terms: D000328:Adult; D016118:Anterior Cruciate Ligament / Q000502:physiology; D000070598:Anterior Cruciate Ligament Injuries / Q000503:physiopathology; D001696:Biomechanical Phenomena; D002102:Cadaver; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000502:physiology*; D008297:Male; D009068:Movement / Q000502:physiology*; D012371:Robotics; D013177:Sports / Q000502:physiology; D019415:Torque; D055815:Young Adult
keywords: Contralateral pairs; Joint simulation; Knee biomechanics; Robotic knee articulation; Side asymmetry