On the kinematic modelling and the parameter estimation of the human shoulder

Development and Evaluation of the Measurement System for the Human Shoulder Joint Based on the 6 DOF Kinematic Modelling

“…Although the other main devices included goniometer, video camera and ultrasonification means, special apparatus and/or mechanism(s) employed for precise measurement of shoulder movement equipped with calibration theory are prerequisites (Meskers et al, 1998a;Wang et al, 1998;Bao and Willems, 1999). These in fact are the interruptions in the application studies in effecting anatomical and physiological anthropology aspects of shoulder movement.…”

“…Although attention has been focused on the faithful expression of anatomical aspects by numerical models, major interests are highly concentrated on the actual measurements derived in shoulder models in expressing skeletal movements with consistency ( Van der Helm FCT et al, 1992;Debski et al, 1995;Wang et al, 1998;Maskers et al, 1998a,b;Bao and Willems, 1999;Maskers et al, 1999;Engin and Peindl, 1987a, b).…”

“…Moreover, the number of variables to be measured is determined by the purpose designated for a particular study, and a uniform approach has yet to be adopted as current approaches on studies by different schools/authors are divergent in this aspect. Bao and Willems (1999) have established measurements by resorting to attachments with 3 units on the thorax, 2 units at the upper distal clavicle and 2 other units of LED markers on the upper arm skin surface with an original Tshape device via a video camera. In the precise measurements conducted by Wang et al (1998), a stylet of the ultrasonic digitizer was used for measurement, and a chip was directly attached to skeletal body landmarks of subjects.…”

“…Within such a range, Bao and Willems (1999) have proposed a new concept focusing on a reference point with fixed distances (fixed distance joint) from the scapuloclavicle and glenohumeral joint. Accordingly, the scapula did not surpass the single link connecting the clavicle and humerus at equidistance, rendering the whole system as a single "shoulder joint".…”

“…Accordingly, the scapula did not surpass the single link connecting the clavicle and humerus at equidistance, rendering the whole system as a single "shoulder joint". The study by Bao and Willems (1999) introduces a concept that slightly differs from the original view that based on the anatomical conception, where accuracy is essentially assured.…”