Yelm man with ‘bionic leg’ to make first-of-its-kind trip up Willis Tower

He’s in shape, so it shouldn’t be a surprise he’s going to attempt to climb the 103 flights of stairs inside Chicago’s Willis Tower this Sunday.

“I ran track and cross country in college.”

But Zac Vawter, who lost his leg in a motorcycle accident, will be doing it with a first-of-its-kind bionic leg.

Vawter, a 31-year-old software engineer from Yelm, lost his leg about three years ago. He was riding home from work on his when the accident happened. He ended up at an Olympia hospital where doctors spent three days trying to save his leg before deciding that amputation was the only option left.

“I have my entire femur, but nothing more, no knee joint,” he told Ross & Burbank.

At the time, he said he knew there were prosthetic options out there, but in a haze of medicine meant to dull the pain from surgery, he didn’t spend a lot of time thinking about it.

The experimental surgery that Vawter underwent next would make it possible for him to become a real-life “bionic man.”

When Vawter’s leg was amputated, a surgeon repositioned the residual spaghetti-like nerves that normally would carry signals to the lower leg and sewed them to new spots on his hamstring. It would allow Vawter one day to be able to use a bionic leg, even though the technology was years away.

The surgery is called “targeted muscle reinnervation” and it’s like “rewiring the patient,” said lead researcher Levi Hargrove of the Rehabilitation Institute of Chicago’s Center for Bionic Medicine. “And now when he just thinks about moving his ankle, his hamstring moves and we’re able to tell the prosthesis how to move appropriately.”

It took about a year for the nerves to grow into Vawter’s muscle and make the thoughts of moving his ankle and foot turn into actual movements.

Hargrove and the other researchers don’t let Vawter take his bionic leg home to Yelm with him. He’s been out to Chicago a few times to use the leg and be observed by the researchers. Movement inside the leg is dependent on an attached battery. When he climbs Willis Tower, researchers will join him, carrying extra batteries in case he needs the extra juice.

Vawter called the leg a “beautiful piece of hardware,” and said that he doesn’t wear pants to cover it up, or his regular prosthetic. “It’s a part of who I am,” he said. “I have great conversations with little kids.”

Experts not involved in the project say the Chicago research is on the leading edge. Most artificial legs are passive. “They’re basically fancy wooden legs,” said Daniel Ferris of the University of Michigan. Others have motorized or mechanical components but don’t respond to the electrical impulses caused by thought.

“This is a step beyond the state of the art,” Ferris said. “If they can achieve it, it’s very noteworthy and suggests in the next 10 years or so there will be good commercial devices out there.”

The $8 million project is funded by the U.S. Department of Defense and involves Vanderbilt University, the Massachusetts Institute of Technology, the University of Rhode Island and the University of New Brunswick.

Vawter and the Chicago researchers recently took the elevator to the 103rd floor of the Willis Tower to see the view after an afternoon of work in the lab. Hargrove and Vawter bantered in the elevator in anticipation of Sunday’s event.

Hargrove: “Am I allowed to trash talk you?”

“It’s fine,” Vawter shot back. “I’ll just defer it all to the leg that you built.”

At the top, Vawter stood on a glass balcony overlooking the city.

It’s no surprise that the man about to climb Willis Tower is ready for trash talk between conversations with kids about not having his leg, his running experience and of course, the fact that he’s wearing a peg leg for Halloween.

AP Medical Writer Carla K. Johnson contributed to this report.