A parallel mechanism of the shoulder-application to multi-body optimisation

作者：El Habachi Aimad; Duprey Sonia; Cheze Laurence; Dumas Raphael^*

来源：Multibody System Dynamics, 2015, 33(4): 439-451.

DOI：10.1007/s11044-014-9418-7

• Shoulder girdle
• Acromial method
• Palpation
• Kinematic constraints
• Scapulothoracic joint angles

This paper describes and evaluates a parallel mechanism of the shoulder girdle. This mechanism was a closed kinematic chain composed of three segments (humerus, scapula and thorax) and three kinematic constraints. The clavicle was modelled as a constant length constraint between the sternoclavicular and acromioclavicular joint centres. The second kinematic constraint was also a constant length between the glenoid cavity and the humeral head for the glenohumeral joint. The third constraint was a point-on-ellipsoid contact for the scapulothoracic joint. Geometrical data required to build this kinematic model were obtained from the Visible Human Project.
The parallel mechanism was then introduced into a multi-body optimisation for the computation of the scapulothoracic joint angles from surface sensors during the abduction of the arm of six able-bodied subjects. The initial guess of this optimisation was obtained by an acromial method. Compared to palpation of scapula anatomical landmarks, the multi-body optimisation with the proposed parallel mechanism allows estimating the shoulder kinematics with a better accuracy than the acromial method alone.

• 出版日期2015-4