A method for determination of upper extremity kinematics.

Kinematic analysis of the upper extremity has been conducted using a wide variety of techniques, philosophies, and analytic methods. We describe a simple, marker-based three-dimensional video analytic technique that borrows concepts from lower extremity kinematic analysis. A sequential rotation order about orthogonal axes is described, although alternate methods are examined as well. The method has been verified by application to a mechanical model. In certain positions, gimbal lock may occur, and a different sequence of rotational decomposition may be required. Agreement on standardization of technique would assist in the dissemination of upper extremity scientific data.