Abstract: Apparatus for assessing posture, limb positions, and limb movements comprising a transmitter and a receiver for application to respective first and second skin positions, a microprocessor, and a biofeedback stimulus unit. The microprocessor measures the travel time of signals between the transmitter and the receiver, assesses the distance between the first and second skin positions based on the travel time of the signals between the transmitter and receiver, generates an actual posture parameter based upon the distance, compares the actual posture parameter with a predetermined target posture parameter stored in said microprocessor means, and generates a signal if the actual parameter is not equal to the target parameter. The biofeedback stimulus unit includes a patient-perceivable signal actuable in response to the signal generated by the microprocessor.