Regaining the ability to control a full weight-bearing standing posture without assistance from weight-supporting devices or other people is a key goal for someone with a spinal cord injury (SCI). The Sayenko lab’s clinical research program focuses on central nervous system plasticity throughout the course of motor learning and regaining sensorimotor function. It has been demonstrated that the human lumbosacral spinal cord can be neuromodulated with epidural spinal stimulation (ESS) and transcutaneous spinal stimulation (TSS) to enable recovery of standing and volitional control of the lower limbs after complete motor paralysis due to SCI. The Sayenko lab is working to identify distinct electrophysiological mechanisms underlying ESS and TSS to define how these approaches determine the ability to maintain self-assisted standing after spinal cord injury. The researchers are applying spinal stimulation therapies in participants with spinal cord injury, finding that participants can maintain an upright standing position either independently or with minimal external assistance applied to the knees or hips, using their hands for upper body balance as needed. The quality of their balance control improves with continued training. When the participants shifted their weight while standing, high levels of leg muscle activity emerge, depending on the amount of muscle loading. These findings suggest that the non-invasive stimulation therapy can modulate the spinal circuitry into a physiological state that enables sensory inputs during weight-bearing to serve as a primary source of neural control to maintain externally unassisted upright posture and balance.