Role of the minimal inertia axis in the kinaesthetic control of unconstrained 3D movements

• Main Author: Hansen, Clint
• Language: English
• Published: Université Paris Sud - Paris XI 2013
• Subjects: [SHS:EDU] Humanities and Social Sciences/Education; [SHS:EDU] Sciences de l'Homme et Société/Education; Motor Control; Biomechanics; Minimum inertia resistance axis; Movement analysis
• Online Access: http://tel.archives-ouvertes.fr/tel-00868211; http://tel.archives-ouvertes.fr/docs/00/86/82/11/PDF/VA2_CLINT_HANSEN_04072013.pdf; http://tel.archives-ouvertes.fr/docs/00/86/82/11/ANNEX/VA_HANSEN_CLINT_04072013_annexe1.pdf

Motor activities of daily life or sports are characterized by complex 3D rotational movements of the upper limbs can be done around distinct axes of rotation (i) joint (ii) inertia or (iii) through the center mass of arms, each under separate repositories. A recent study showed that within the constraints of speed, a change of axis of rotation occurs in the context of the implementation of a simple rotation of the arm relative to the trunk (Isableu et al., 2009) . In this context, the aim of the thesis was to complete this first analysis to evaluate the robustness of the assumption that the axes around which organizes the movement depends on the speed of motion and the constraints task in general. The assumption is that the axis corresponding to the minimum inertia reduced variability seen with speeds which increase with respect to a center axis associated with the mass (shoulder mass center of the upper limb) and geometric (pin-shoulder elbow). This study is done by considering "simple" and complex athletic movements including movements. Thus, studies have focused on the influence of the task constraints and their impact on the choice of axes of rotation. Firstly the role of initial instruction is tested. Secondly, the variability of the axis of minimum inertia is estimated in a precise task. Thirdly, the hypothesis is tested in an interception task that involves time constraints. Finally, we tested the role of axes in complex gestures, high speed, especially during launch and broken arm during the tennis serve. The results are used to discuss the hypothesis of the importance of the axis of minimum inertia during the execution of voluntary movements of the upper limb.