A high-tech prosthetic leg enables amputees to walk naturally and at normal speeds without consciously thinking about it, a study suggests. Developed by scientists at Massachusetts Institute of Technology, the bionic leg links the user's brain activity to nerves in important muscles controlling movement. Study author Prof Hugh Herr said the results of a small trial were "quite miraculous" and could influence the way prosthetic limbs are constructed in future.
But there are years of development work still to be carried out before it can be used by more patients. There are lots of limitations to the way current artificial limbs are able to move, say the researchers in Nature Medicine . Their quest was to test whether new technology could make walking with a leg amputation below the knee more natural.
Normally, during amputation, muscles are wrapped up to create soft padding for maximum comfort when using an artificial leg. But this means control of nerves and natural leg movements are lost. With the new technology, surgery to reconnect vital pairs of muscles on the leg stump is needed first - either during the amputation or later on.
Then, using sensors on these muscles, signals are sent to a robotic controller which helps the prosthetic leg calculate how much to bend the ankle and how much power to deliver when walking. Information from muscle nerves is communicated to the prosthesis and then back to the patient, resembling the way a real limb works. "So when the amputee think.