title: Validation of a six degree-of-freedom robotic system for hip in vitro biomechanical testing.
abstract: Currently, there exists a need for a more thorough understanding of native hip joint kinematics to improve the understanding of pathological conditions, injury mechanisms, and surgical interventions. A biomechanical testing system able to accomplish multiple degree-of-freedom (DOF) movements is required to study the complex articulation of the hip joint. Therefore, the purpose of this study was to assess the repeatability and comparative accuracy of a 6 DOF robotic system as a testing platform for range of motion in vitro hip biomechanical analysis. Intact human cadaveric pelvises, complete with full femurs, were prepared, and a coordinate measuring machine collected measurements of pertinent femoral and pelvic bony landmarks used to define the anatomic hip axes. Passive flexion/extension path and simulated clinical exam kinematics were recorded using a 6 DOF robotic system. The results of this study demonstrate that the 6 DOF robotic system was able to identify hip passive paths in a highly repeatable manner (median RMS error of <0.1mm and <0.4°), and the robotically simulated clinical exams were consistent and repeatable (rotational RMS error ≤0.8°) in determining hip ranges of motion. Thus, a 6 DOF robotic system is a valuable and effective tool for range of motion in vitro hip biomechanical analysis.
authors.affiliation: Steadman Philippon Research Institute, Vail, CO, USA.
authors.forename: Mary T
authors.initials: MT
authors.lastname: Goldsmith
authors.affiliation: Steadman Philippon Research Institute, Vail, CO, USA.
authors.forename: Matthew T
authors.initials: MT
authors.lastname: Rasmussen
authors.affiliation: Steadman Philippon Research Institute, Vail, CO, USA.
authors.forename: Travis Lee
authors.initials: TL
authors.lastname: Turnbull
authors.affiliation: Steadman Philippon Research Institute, Vail, CO, USA.
authors.forename: Christiano A C
authors.initials: CAC
authors.lastname: Trindade
authors.affiliation: Steadman Philippon Research Institute, Vail, CO, USA; The Steadman Clinic, Vail, CO, USA.
authors.forename: Robert F
authors.initials: RF
authors.lastname: LaPrade
authors.affiliation: Steadman Philippon Research Institute, Vail, CO, USA; The Steadman Clinic, Vail, CO, USA. Electronic address: mjp@sprivail.org.
authors.forename: Marc J
authors.initials: MJ
authors.lastname: Philippon
authors.affiliation: Steadman Philippon Research Institute, Vail, CO, USA.
authors.forename: Coen A
authors.initials: CA
authors.lastname: Wijdicks
mesh_terms: D000328:Adult; D001696:Biomechanical Phenomena; D005269:Femur / Q000502:physiology; D006621:Hip Joint / Q000502:physiology*; D006801:Humans; D008875:Middle Aged; D009068:Movement; D016059:Range of Motion, Articular; D012371:Robotics
keywords: Hip; Hip range of motion; Kinematics; Robotics/instrumentation; Simulated clinical exam