INTRODUCTION Investigators have used a variety of marker sets and methods to describe upper extremity kinematics. However, without a standard set of anatomical and joint coordinate system definitions for 3-D motion analysis (3DMA), data sets cannot be compared between investigators. In an effort to summarize the descriptions of upper extremity motion, Wu and colleagues [1] published a set of joint coordinate system recommendations. This proposed kinematic solution is an extension from that standard. The purpose of this investigation is to develop an anatomically based wrist joint coordinate system (WJCS) and appropriate tracking frames. To test this new WJCS a comparison between the 3-D motion analysis (3DMA) implementation, manual goniometry (MG), and electro-goniometry (EG) was performed. We hypothesize that 3DMA would provide increased accuracy over the other methods.