Augmenting Reactive Stepping With FES After SCI

Inclusion Criteria: 1. have a motor incomplete SCI (i.e., AIS grade C or D) that is non-progressive; 2. be at least one year post-injury (i.e., chronic injury); 3. ≥ 18 years old; 4. be able to stand independently for 60 sec; 5. unable to take a step bilaterally without physical assistance or upper extremity support; 6. able to understand spoken English; 7. free of any other condition besides SCI that significantly affects walking or balance (e.g., no vestibular disorder, significant vision loss, stroke); 8. be able to provide informed, written consent. Exclusion Criteria: 1. Contraindications for EMS. Electrical stimulation will not be used if: * it will be applied to areas where it could cause malfunction of electronic devices, including cardiac pacemakers; * a woman is pregnant; * the applied region has known or suspected malignancy; * the person has active deep vein thrombosis or thrombophlebitis; * there are active bleeding tissues, or the person has untreated hemorrhagic disorders; * there are infected tissues, tuberculosis, or wounds with underlying osteomyelitis; * tissues have been radiated in the past six months; * there are damaged skin areas or at-risk skin areas that would result in uneven conduction of current; 2. severe spasticity is present in the legs; 3. the person has contractures in the lower limbs that prevent achieving a neutral hip and ankle position, or extended knee; 4. there is a history of prior lower limbs fragility fracture; 5. the leg muscles are unresponsive to electrical stimulation (i.e., peripheral nerve damage in the legs). 6. Pressure sores on pelvis or trunk, where safety harness will be donned.