Improve Dynamic Lateral Balance of Humans With SCI

Inclusion Criteria: 1. age between 18 and 65 years; 2. medically stable with medical clearance to participate; 3. level of the SCI lesion between C4-T10; 4. passive range of motion of the legs within functional limits of ambulation; 5. ability to walk on a treadmill for more than 20 minutes with partial body weight support as needed and short sitting/standing breaks; 6. ability to ambulate without orthotics or with orthotics that do not cross the knee for more than 10 meters Exclusion Criteria: 1. the presence of unhealed decubiti, existing infection, severe cardiovascular and pulmonary disease, concomitant central or peripheral neurological injury (e.g. traumatic head injury or peripheral nerve damage in lower limbs); 2. history of recurrent fractures and/or known orthopedic injury to the lower extremities; 3. Botox injection within 6 months of starting the study, and current receiving physical therapy treatment; 4. have metallic implantation in the spinal region underneath where electrodes may be placed.