Estimating shoulder-complex mobility

Article type: Research Article

Authors: Tondu, Bertrand

Affiliations: LESIA, Département de Génie Electrique, Institut National de Sciences Appliquées, Campus Universitaire de Rangueil, 31077 Toulouse France

Note: [] Corresponding Author: Bertrand Tondu, LESIA, Département de Génie Electrique, Institut National de Sciences Appliquées, Campus Universitaire de Rangueil, 31077 Toulouse, France. Tel: (33) 5 62 26 67 42; Fax: (33) 5 61 55 98 00; E-mail: bertrand-tondu@insa-toulouse.fr

Abstract: Modeling shoulder motions is essential in understanding upper-limb dynamic behavior. However, the mobility of the shoulder complex—in terms of degrees of freedom (DOFs)—is seldom quantified. In this paper we propose applying the theory of mechanisms and, especially, the powerful Grübler–Kutzbach formula to estimate it. This approach requires a rigorous kinematic analysis. So we suggest basing it on a bone schematisation derived from an extension of Dempster's historical notation associated to mechanical interpretation of the physiological joints involved. In so doing, the proposed shoulder complex mobility leads to justifying a nine-DOF serial-chain upper-limb mode, which extends the classical seven-DOF arm–foream–wrist model and completing it by adding a clavicle-like link with a two-DOF mobility.

Keywords: Shoulder complex, mobility, kinematic modelling of bones and joints

DOI: 10.1080/11762320701403922

Journal: Applied Bionics and Biomechanics, vol. 4, no. 1, pp. 19-29, 2007