While the risk factors for musculoskeletal disorders of the upper extremity include physical risk factors, such as force and posture, the measurement of these factors during computer work has been limited to primarily laboratory studies. A portable system for field use was designed which measured forces applied to the keyboard and mouse, the patterns of the forces as well as tracking keystrokes, mouse movements, and wrist postures. Application of this system is planned for a series of laboratory and field studies.