A Prosthetic Arm That Acts Like a Real One

Patients use nerves left intact after amputations to control prosthetic limbs.

A new technique that capitalizes on remaining nerves allows amputees to intuitively control their prosthetic limb, providing them with a much better level of control than traditional prosthetics.

In a paper published today in The Lancet, scientists at the Rehabilitation Institute of Chicago described a procedure to surgically transplant nerves from the shoulder to the upper-chest muscle of a woman who had lost her arm in a motorcycle accident. The rerouted nerves then grew into the muscle, which amplified the messages once sent to muscles in the arm and hand; those signals are read by sensors on the prosthetic limb and translated into movement. The patient also developed a surprising degree of sensory perception in the upper chest, which scientists say will be key in the next generation of prosthetics.