Spinal Cord Transcutaneous Stimulation Enables Volitional Knee Extension in Motor-complete SCI

Non-invasive spinal cord transcutaneous stimulation (scTS) is often applied to one or multiple spinal segments and may improve motor control after spinal cord injury (SCI). The purpose of this pilot study was to apply tonic scTS to an individual with motor-complete spinal cord injury (SCI) in order to initiate and maintain volitional control during a specific lower-extremity motor task. The participant's legs were placed in a gravity-neutral position, and he was asked to extend his knee, with and without the presence of tonic scTS. Our results show intentional voluntary control of knee extension with scTS (with no assistance). Our preliminary findings highlight how scTS neuromodulation of the spinal circuitry has the potential to restore motor function for people with motor-complete SCI. Clinical Relevance- This investigation is critical to better understand the neuromodulatory effects of tonic scTS for augmentation of voluntary-induced muscle activations in individuals with motor-complete SCI.