A Biomechanical Analysis of the Functions of the Deltoid during Abduction of the Arm

Abstract

In this paper a method is presented for the analysis of the functions of the deltoid during abduction of the arm. The influence of several parameters such as the active and passive properties of the muscle, the length of the muscle fibres at certain positions of the arm, the kind of attachment of the deltoid to the scapula and the clavicula and the rotation of the scapula are discussed with respect to the behaviour of the muscle. The importance of the centre of rotation of the humerus in relation to the required equilibrium is shown.