Quantitation of human shoulder anatomy for prosthetic arm control--II. Anatomy matrices.

Part I presented mathematically continuous surfaces and origin-to-insertion centroidal trajectory data for the muscles of the human shoulder. Part II presents linear trajectory data for the same muscles, in addition to kinematic descriptions of the joints. 'Anatomy' matrices for musculature, which convert muscle forces (as estimated by cutaneously monitored EMG signals) to moments, within a prosthetic arm controller, are developed for both the linear and non-linear (centroidal) data, and then compared. Graphical analyses of the muscle functions are also presented via computer-generated 'circle diagrams'.