A Kinematic Model of the Upper Limb Based on the Visible Human Project (VHP) Image Dataset.

A kinematic model of the arm was developed using high-resolution medical images obtained from the National Library of Medicine's Visible Human Project (VHP) dataset. The model includes seven joints and uses thirteen degrees of freedom to describe the relative movements of seven upper-extremity bones: the clavicle, scapula, humerus, ulna, radius, carpal bones, and hand. Two holonomic constraints were used to model the articulation between the scapula and the thorax. The kinematic structure of each joint was based on anatomical descriptions reported in the literature. The three joints comprising the shoulder girdle - the sternoclavicular joint, the acromioclavicular joint, and the glenohumeral joint - were each modeled as a three degree-of-freedom, ideal, ball-and-socket joint. The articulations at the elbow and wrist - humeroulnar flexion-extension, radioulnar pronation-supination, radiocarpal flexion-extension, and radiocarpal radial-ulnar deviation - were each modeled as a single degree-of-freedom, ideal, hinge joint. Locations of the joint centers and joint axes were derived by graphically inspecting the three-dimensional surfaces of the reconstructed bones. The relative positions of the bones were defined by fixing a reference frame to each bone; the position and orientation of each reference frame were based on the positions of anatomical landmarks and on the shapes of the reconstructed bone surfaces. Tables are provided which specify the positions and orientations of the joint axes and the bone-fixed reference frames for the model arm.