Objective : With clinical application in mind, we developed a method to measure the movement of a selected joint three-dimensionally as a conic domain (joint sinus cone). The method was applied to shoulder joint motion during daily living activities exercises in a group of hemiparetic poststroke patients. The results were compared to the exercise range of physically unimpaired persons. Methods : The subjects dressed in jackets and performed certain other tasks in a sitting position and the range of motion of the shoulder joint in three dimensions was measured using a 6-dimensional electromagnetic tracking system. Measurement results were analyzed with a plane display using a Lambert Azimuthal equal area. Results : This method was able to determine findings difficult to see with the naked eye, such as the narrow range of motion in a paralyzed shoulder joint and poor functionality also in the contralateral shoulder. Conclusion : The dressing measurement was achieved using magnetic measurement equipment. By displaying the results through a map projection it was possible to appreciate the whole range of the motion. Because this method facilitates the expression of complex joint exercise ranges, it will be useful in the analysis of daily behavior restrictions due to impairment.