A Technique for Measuring Clothed Range of Joint Motion

Abstract

The study of range of joint motion is of theoretical and practical interest to basic research, workspace design, rehabilitation, and mathematical models. Nude range of motion has been extensively explored, whereas range of motion under clothed conditions, although equally important in applications, has received less attention. A project was designed to investigate modern instrumentation and methodologies for examining clothed range of joint motion. An empirical study was conducted using three distinct techniques simultaneously, involving 6 subjects, two military ensembles, and 46 planar motions. The results of the study showed one of the techniques, a computerized six-degree-of-freedom electromagnetic tracker, to be superior for joint motion applications under clothed conditions. Customized physical modifications and software were implemented to adapt the device for physiological applications, and algorithms were created for extracting joint motion information. Standardized procedures for performance strategies were defined. Recommendations were also given for the use of the other two techniques in applications having different requirements.