1. An apparatus for providing a wearer with information indicative of spatial orientation of a body part of said wearer, said apparatus comprising: a motion sensing system to be worn by a wearer, said motion sensing system generating a motion signal indicative of motion experienced by said body part of said wearer; a signal processor in communication with said motion sensing system for generating an estimate of said spatial orientation of said body part on the basis of said motion signal; an encoder in communication with said signal processor, said encoder configured to generate said feedback signal on the basis of said estimate of said spatial orientation; and a stimulator responsive to said feedback signal from said encoder, said stimulator configured to provide a signal to a nervous system of said wearer in response to said feedback signal;