Falls constitute a major cause of injury amongst the elderly. Falls may result in debilitating injuries, reduced mobility, and reduced independence, all of which may in turn result in a spiral of decline. In order to more fully understand the causes and effects of falls it is necessary to document the biomechanics of falls. Physical Optics Corporation proposes to develop the Fall Orientation Proprioceptive Sensor (FOPS) system, a system of compact inertial sensors that sense the accelerations and rotations of the object to which they are attached. By attaching these sensors to the limbs and torso of a human subject, it is possible to track the movement and configuration of the body as it falls. The actual sensors employed are microfabricated on the surface of a microchip that includes monolithic signal processing and conditioning circuitry. With appropriate packaging, the sensor clusters will take up less than 1 cc of space. In addition, inertial sensors are entirely self-contained, eliminating the need for external references and conferring immunity to external interference. As a result, it is possible to construct a compact in situ sensor system to monitor the motion of the body during falls. PROPOSED COMMERCIAL APPLICATION: The FOPS system, when successfully developed, will be of great utility within sports medicine, ergonomics, and time/motion analysis. The system is capable of measuring the motion of the body in many environments in which videometric of magnetic systems are not viable. This system will be particularly useful for in situ studies, such as the analysis of the motion of a delivery man or a football player.