Training to walk amid uncertainty with Re-Step: measurements and changes with perturbation training for hemiparesis and cerebral palsy.

Purpose: To describe Re-Step™, a novel mechatronic shoe system that measures center of pressure (COP) gait parameters and complexity of COP dispersion while walking, and to demonstrate these measurements in healthy controls and individuals with hemiparesis and cerebral palsy (CP) before and after perturbation training.

Method: The Re-Step™ was used to induce programmed chaotic perturbations to the feet while walking for 30 min for 36 sessions over 12-weeks of training in two subjects with hemiparesis and two with CP.

Results: Baseline measurements of complexity indices (fractal dimension and approximate entropy) tended to be higher in controls than in those with disabilities, while COP variability, mean and variability of step time and COP dispersion were lower.