The Apparatus for Measuring the Three Dimensional Motion of the Shoulder Complex

Abstract

a) A new apparatus for measuring the three di mensional motion and the rotation of the shoulder complex has been developed using a personal computer system. b) A new concept of 3D% ROM is introduced. By measuring 3D % ROM, it is possible to evaluate the maximum circumduction of the shoulder complex quantitatively. The normal values of 3D% ROM are more than 38 %. c) In n ormal shoulders, external rotation angle increases rapidly during abduction 90° -135° and with 180° abduction the average external rotation is 96° . With 180° flexion, the average internal rotation is 27° . In painful arc syndrome shoulders, during abduction external rotation increases less than normal shoulders. But during flexion the pattern of internal rotation is similar to normal shoulders.