抄録
Machines and tools in a work situation should be within the reach of arm movements of the operator in his sitting posture. In other words, the operator should not be required to leave his normal working position to operate his machine. The normal working area and maximum working area of the arm in three dimensions were measured. The equations related or a nomograph was constructed from the measurement data, from which can be known the necessary values associated with the total span. This nomograph would be of aid to designers of various industrial machines. In arm movement the shoulder or elbow does not stay at a fixed point, but rather moves outward or upward. The movement of the scapula occurs with that of humerus. The arrangement of controls in the working area should be evaluated also from other aspects.