Détermination des efforts articulaires exercés au cours de trois types d'élan en barre fixe

Abstract

Aims – Assess the forces and moments of the joints responsible for producing the segmental motions involved in a series of large circling movements culminating in a « tkatchev» release-regrasp skill.Methods – A planar eight-link kinematic chain was considered. The Newton–Euler formalism was used to determine the forces and moments involved in the moving kinematic chain. The dynamic model was formulated using a recursive formulation of joint velocities and accelerations from the distal segment to the proximal one.Results – During the standard and accelerated giant swings, the tensile forces increased as the gymnast turn from 60° to 240° and reached a maximum of two bodyweight (BW) for the upper limb joints at the lower vertical (180°). This maximal value was 3 BW at 160° during the swing in preparation to the « tkatchev». The magnitude of the components of the bar reaction reached largest values (4.5, 6 and 4 BW) when the gymnast turn at 60°, 160° and 250° during the preparatory swing.Conclusion – Compared to the other ones, this last swing required at the hip and shoulder joints, larger values of moment ranging from −200 to 300 Nm when the body turn from 125° to 160°.