The effects of spinal cord injuries are complex and multifaceted. People lose not only the ability to control the movement of their limbs, but also the ability to receive sensory feedback from them. Both are critical to generate the coordinated movement involved in walking.

In a study in Nature Biomedical Engineering, the researchers report results from a clinical trial involving three people who had lost the use of their legs following complete spinal cord injuries.

The participants received electrical stimulation of the spinal cord from electrode arrays implanted both above and below their injury sites. The study found that stimulation below the injury could partially restore muscle control in the lower extremities, while stimulation above the injury enabled participants to understand where their legs were located in space as they walked, with the assistance of physical therapists, on a treadmill.