Hacking Nerves to Revive Paralyzed Limbs

A neural engineer from Case Western Reserve University is reviving paralyzed limbs with an electricity hack. It's a brilliant workaround for spinal cord injuries, and it may someday let paraplegics activate their legs just by pushing a button.

It's not just a pipe dream or a theory; clinical trials have already shown some success. People with spinal cord injuries are unable to send signals to their lower body muscles, but CWRU's Matthew Shiefer's been able to bypass that problem by sending electrical pulses directly to nerves. It's a way to simulate the messages your legs would be receiving from your brain.

Schiefer has developed a working flat interface nerve electrode that flattens nerves to bring fiber bundles to the surface, where they're closer to the electrodes that shock muscles into movement.

The cuff was temporarily implanted on the femoral nerves of seven patients undergoing routine thigh surgery. Pulses of current 250 microseconds long were used to selectively and independently activate the muscles that extend the knee and flex the hip joint when a person stands up. The pulses were not enough to bend the joints as much as they would when standing, but the results suggest that longer pulses should stimulate the muscles to provide enough force to support the body's weight.

The ability to flex a paralyzed muscle is huge, but obviously still a ways off from actually being able to walk. It's important to note, too, that Shiefer has so far only conducted successful testing on able-bodied individuals—spinal cord injuries are the next step. Still, the success so far outlines a road map for the future; hopefully one in which paralyzed people can find their legs again. [New Scientist via PopSci; image via Matthew Shiefer, Case Western University]