About this trial

This trial is enrolling individuals with spinal cord injuries to evaluate the effectiveness of acute intermittent hypoxia therapy (AIH) combined with transcutaneous (skin surface) spinal cord stimulation on walking and balance function. AIH is a procedure wherein the oxygen level of breathed air is reduced for a short duration (<2 min), alternated by exposure to room air with normal oxygen levels. Spinal cord stimulation is believed to activate spinal cord nerve networks. For comparison, there are three arms to the study: 1) AIH + spinal cord stimulation + gait training; 2) sham (inactive) AIH + spinal cord stimulation + gait training; and 3) sham AIH + sham spinal cord stimulation + gait training. At the end of each arm participants will cross over to another arm, and will therefore receive all three arms. The main goal is to see if AIH and spinal cord stimulation improves gait and walking function, posture and balance, and cardiovascular conditioning.