抄録
We produced the apparatus for measuring the motion of the shoulder joint in order to analyse the shoulder movement quatitativety and three dimentionally. This apparatus has a gimbal which has two degrees of freedom and a telescoping tube which has one degree of freedom. Two angles of rotation of a gimbal and a tube displacement are detected by optical rotary encoder. The personal computer takes on these signals through the counter.
A subject's trunk is held by standing fram e and his arm is placed on a straight posterior elbow splint. The L shaped bar is attached to the posterior elbow splint and protrudes from it. The tip of the bar is connected with the end of the tube. When the subject moves his arm, the locus of the end of the tube is projected in the horizontal plane, the sagittal plane and the coronal plane. These projection are displayed on the monitor TV and the data are stored in diskets. The personal computer calculates the range of motion of the shoulder.
Furthermore, we made the program for measu r ing the maximum area of motion of the shoulder. If a subject moves his arm, the path of motion lies on a sphere of which center correspods to the shoulder joint. The maximum area of motion is indicated by the percentage of the whole spherical surface.32 narmal shoulders were analysed. The mean percentage was 50 %.
