Development of a mobile motion capture (MO ² CA) system for future military application

State-of-the-art three-dimensional motion analysis systems, which are utilized to predict, diagnose, and treat many musculoskeletal and neurological disorders, are expensive and space consuming. These systems have only been widely used in large research facilities because of their lack of this transportability. Since device portability is a critically important in the military, most small military hospitals are therefore deprived of these systems. The purpose of this study was to develop a mobile motion capture system, MO ² CA, to automatically detect the movement of the human body. Twenty healthy young adults participated in this study. Colored tape was attached on the heel, and subjects walked on the treadmill at three different speeds: Preferred, fast, and slow. Two motion capture systems were used concurrently: Qualisys (100 Hz) and MO ² CA (60 Hz). Four dependent variables were: Stride length, stride time, stride length variability, and stride time variability. Paired t-tests, Pearson correlation, and Bland-Altman plots were used to investigate the statistical differences between two systems. No significant differences were found for all dependent variables. Regression and Bland-Altman plots showed strong agreements between the two systems. Our MO ² CA shows a potential for real-time tracking of biomechanical changes in gait, which is extremely important for military use.