title: Verifying the equivalence of representations of the knee joint moment vector from a drop vertical jump task.
abstract: Biomechanics software programs, such as Visual3D, Nexus, Cortex, and OpenSim, have the capability of generating several distinct component representations for joint moments and forces from motion capture data. These representations include those for orthonormal proximal and distal coordinate systems and a non-orthogonal joint coordinate system. In this article, a method is presented to address the challenging problem of evaluating and verifying the equivalence of these representations. The method accommodates the difficulty that there are two possible sets of non-orthogonal basis vectors that can be used to express a vector in the joint coordinate system and is illuminated using motion capture data from a drop vertical jump task.
authors.affiliation: Department of Mechanical and Aerospace Engineering, University of California at Los Angeles, Los Angeles, CA 90095, USA.
authors.forename: Julia K
authors.initials: JK
authors.lastname: Nichols
authors.affiliation: Department of Mechanical Engineering, University of California at Berkeley, Berkeley, CA 94720, USA. Electronic address: oreilly@berkeley.edu.
authors.forename: Oliver M
authors.initials: OM
authors.lastname: O'Reilly
mesh_terms: D000465:Algorithms; D001696:Biomechanical Phenomena; D003198:Computer Simulation; D006801:Humans; D007719:Knee Joint / Q000502:physiology*; D009068:Movement / Q000502:physiology*; D016059:Range of Motion, Articular; D013647:Task Performance and Analysis
keywords: Dual Euler basis; Joint coordinate system; Joint forces; Joint moments; Joint rotations