To develop a network of microminiature, three degree of freedom joint orientation and inclination tracking modules (3DM-G’s), designed for use with functional electrical stimulation (FES) systems. Solid State accelerometers, magnetometers, and angular rate gyros are used to detect Earth’s magnetic and gravitational field vectors, and an embedded processor (within each networked 3DM-G) is used to resolve pitch, roll, & yaw orientations as well as to provide digital filtering.