 ViMove Testing Groups A B: The ViMove system dorsaVi, Australia which will be used to assess movement patterns and lumbar muscle activity in both groups during the ViMove standard assessment, 30 sec chair test, 40m walk test, is an inertial measurement system comprised of two wireless motion sensors containing a triaxial accelerometer, a triaxial gyroscope and a magnetometer, two wireless surface electromyography EMG sensors, and a small wireless recording device RFD that can be worn by the subject. The manufacturer reports average differences of 1 degree for single plane, through range movements when comparing matched measurements from the ViMove and a Fastrak opto-electronic device Charry, Umer et al. 2011. The ViMove motion sensors collect data at approximately 20 Hz. 