Hugh Herr

The limbs are not directly controlled by my nervous system.

I can't think and move them, nor can I feel my limbs.

It feels like I'm walking on powerful robots.

It feels like I'm being walked.

It feels like I'm in the backseat of the car.

The surgery was done at Brigham Women's Hospital in Boston under the direction of Matthew Carty, a critical colleague and collaborator.

And what we did in Jim's leg is we connected his muscles within his amputated residuum in natural ways, the calf muscle to the muscle in the front of the leg called the tibialis anterior, so that when Jim thinks after the surgery,

those muscles move dynamically in a similar way to how they moved when he had an intact leg.

So what that does is it tells the brain how the ankle should move.

Now, it's not a physical ankle after the amputation.

It's a phantom ankle.

But when Jim closes his eyes and moves his phantom ankle, he feels the full dynamics of that sensation.

He can point his toes.

He can go the other way from pointing his toes down like a ballerina to pointing his toes to the ceiling.

And he actually feels it as if his foot ankle were intact and biological.

We hypothesized that he would have those sensations and he would be better able to control the prosthesis because of those muscle dynamics.

But it was a hypothesis.

And when we actually saw it with our own eyes, it was a remarkable day in the laboratory.

We electrically linked Jim's amy muscles via the electrodes to a bionic limb, and Jim quickly learned how to move the bionic limb in four distinct ankle-foot movement directions.

We were excited by these results, but then Jim stood up, and what occurred was truly remarkable.