Wallace, 61, left his trademark beret on the defense table as he took the witness stand to say he's been permanently affected by an Achilles tendon injury he suffered when he got tangled in loose wires on stage at the Bellagio in December 2007.
"To this day, I can't run off the stage. I can't dance," he told the jury hearing a fifth day of testimony in Wallace's civil negligence lawsuit against the Bellagio.
"I can't do anything without thinking about, 'Am I going to hurt my leg?'" he said. "I can't even get up like I used to. I have to take my time."
Wallace's testimony in Clark County District Court is scheduled to resume Friday.
The comedian's attorney, Dominic Gentile, has said he'll ask the jury to award $9 million in damages to the veteran stand-up entertainer.
Bellagio lawyers led by Paul Haire say Wallace had a pre-existing injury, that he was careless during his private performance for a corporate group in a ballroom room with about 100 seats, and that he voluntarily assumed the risk of injury.
Wallace's close friend, comedian Jerry Seinfeld, watched several minutes of jury selection last Friday but wasn't in court when Wallace took the witness stand Thursday.
Earlier, jurors heard another Wallace friend, Gladys Knight & the Pips performer Merald "Bubba" Knight Jr.
Knight, the older brother of singer Gladys Knight, said he was backstage during Wallace's show and didn't see him get hurt. Wallace completed the show.
Knight said he helped his limping friend to a chair afterward, then asked hotel employees to fetch a wheelchair so Wallace could get to a car for the short drive down the Strip to his next gig.
Wallace performed again that night at the Flamingo hotel-casino, where he has headlined since 2004.
"That's what we're made of as professional performers," Knight told the jury. "The 'show must go on' mentality. If you're in show business, you know what I'm talking about."
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