抄録
The purpose of this study is to develop the scapula mechanism for the robotic shoulder model. Human shoulder has the largest motion range in human musculoskeletal mechanism. So-called 'Shoulder' consists of Humerus, Scapula, Clavicle and Thorax. Scapulo-humeral joint has a ball joint mechanism that moves in 3-degrees of freedom in single joint. Scapulo-thoracic sliding extends a range of motion of the ball joint and stabilizes upper limb with Scapulo-clavicle joint. Authors thought that the shoulder girdle complex is one of the adequate mechanisms to construct compact and lightweight joint system for living body. In previous paper, authors reported the development of the robotic Scapulo-humeral mechanism that had the ball joint mechanism and was driven by 6 wires. Consequently, authors tried to develop the Scapulo-thoracic articulation mechanism to reveal harmonic motion of shoulder complex. This paper describes the development of the Scapula mechanism robot. Muscles for actuating Scapula were substituted by wires according with anatomical literature and Thorax was reduced to a sphere surface. The scapula part was stabilized by the clavicle part in which the proximal joint of the clavicle part was connected to the breastbone position. The movability in this mechanism was confirmed by estimation of moment arm, and the Scapula part was driven by 8 wires as a robotic system successfully.
