title: Multibody kinematics optimization with marker projection improves the accuracy of the humerus rotational kinematics.
abstract: Markers put on the arm undergo large soft tissue artefact (STA). Using markers on the forearm, multibody kinematics optimization (MKO) helps improve the accuracy of the arm kinematics especially its longitudinal rotation. However deleterious effect of STA may persist and affect other segment estimate. The objective was to present an innovative multibody kinematics optimization algorithm with projection of markers onto a requested axis of the local system of coordinates, to cancel their deleterious effect on this degree-of-freedom. Four subjects equipped with markers put on intracortical pins inserted into the humerus, on skin (scapula, arm and forearm) and subsequently on rigid cuffs (arm and forearm) performed analytic, daily-living, sports and range-of-motion tasks. Scapulohumeral kinematics was estimated using 1) pin markers (reference), 2) single-body optimization, 3) MKO, 4) MKO with projection of all arm markers and 5) MKO with projection of a selection of arm markers. Approaches 2-4 were applied to markers put on the skin and the cuff. The main findings were that multibody kinematics optimization improved the accuracy of 40-50% and the projection algorithm added an extra 20% when applied to cuff markers or a selection of skin markers (all but the medial epicondyle). Therefore, the projection algorithm performed better than multibody and single-body optimizations, especially when using markers put on a cuff. Error of humerus orientation was reduced by half to finally be less than 5°. To conclude, this innovative algorithm is a promising approach for estimating accurate upper-limb kinematics.
authors: Department of Kinesiology, Université de Montréal, Montreal, QC, Canada H3C 3J7. Electronic address: mickael.begon@umontreal.ca.
authors: Mickaël
authors: M
authors: Begon
authors: Department of Kinesiology, Université de Montréal, Montreal, QC, Canada H3C 3J7.
authors: Colombe
authors: C
authors: Bélaise
authors: CIC INSERM 1432, Plateforme d'Investigation Technologique, CHU Dijon, France.
authors: Alexandre
authors: A
authors: Naaim
authors: Karolinska Institutet, Stockholm, Sweden.
authors: Arne
authors: A
authors: Lundberg
authors: Univ Lyon, Université Lyon 1, IFSTTAR, LBMC UMR_T9406, F69622, Lyon, France.
authors: Laurence
authors: L
authors: Chèze
mesh_terms: D000203:Activities of Daily Living; D000328:Adult; D000465:Algorithms; D016477:Artifacts; D001696:Biomechanical Phenomena; D006801:Humans; D006811:Humerus / Q000502:physiology*; D008297:Male; D009068:Movement / Q000502:physiology*; D016059:Range of Motion, Articular; D012399:Rotation; D013177:Sports; D034941:Upper Extremity / Q000502:physiology*
keywords: Marker projection algorithm; Multibody kinematics optimization; Upper-limb