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Amputee with bionic leg walks up 103 floors

Zac Vawter, 31, fitted with an experimental bionic leg, checked out the view from the Willis Tower in Chicago on Thursday. The leg’s movements are controlled by his brain.

Brian Kersey/Associated Press

Zac Vawter, 31, fitted with an experimental bionic leg, checked out the view from the Willis Tower in Chicago on Thursday. The leg’s movements are controlled by his brain.

CHICAGO — A 31-year-old amputee made history Sunday, becoming the first person to climb 103 floors of one of the world’s tallest skyscrapers with a bionic leg.

Zac Vawter was wearing a prosthetic leg controlled by his brain when he took part in ‘‘SkyRise Chicago’’ inside the Willis Tower. The charity event raises funds for the Rehabilitation Institute of Chicago.

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The event marked the bionic leg’s first test in the public eye.

As Vawter thought about climbing stairs, the motors, chains, and belts in his leg synchronized the movements of its ankle and knee. Researchers cheered him on and noted the smart leg’s performance.

Institute officials say the leg and its climber held up fantastically. Vawter finished the climb in about 45 minutes.

Also participating in the charity event was US Senator Mark Kirk, Republican of Illinois, who was making his first public appearance since suffering a major stroke in January.

Gripping a handrail and wearing a brace on his left leg, Kirk climbed 37 floors of the tower. He started walking from the 66th floor and climbed up to the finish line at the 103d floor.

He was met with hugs and cheers from family and friends at the end. The senator paced slowly through the crowd with the help of a cane, smiling but saying little to the media.

Kirk, 53, has had severely limited movement on the left side of his body since the stroke.

‘‘We’ve seen some amazing progress over the last few months,’’ said Michael Klonowski, a physical therapist with the Rehabilitation Institute, where Kirk is receiving treatment. ‘‘As an in-patient, he needed significant help. Now here he is going up the stairs without my help.’’

Kirk prepared for the event by scaling stairs and incrementally increasing the height he climbed.

Kirk continues to undergo rehabilitation and has been releasing videos on his progress.

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