 Similarly the CV function might be assessed without with stimulation. The orthostatic stress test might be repeated with optimal stimulation for CV control. The butterfly catheter will remain in place from the initial non stimulation test and blood samples will be obtained to same time points to assess if any changes in We will also identify appropriate stimulation parameters for inducing stepping and standing in combination with manual assistance using body weight support on a treadmill BWST or overground in the case of standing. Each of the sixteen electrodes will be independently stimulated using subthreshold, tonic, non-patterned epidural stimulation applied at frequencies of 5-50 Hz, and amplitudes of 1-10 V. The specific stimulation parameters will be optimized for each individual to achieve the best motor performance for each task. We may monitor continuous blood pressure, breathing rate and temperature using external sensors pasted over the skins during training sessions or experiments. 