“Here’s a woman, she’s supposed to fight all these different things and she can’t make it 15 feet to her car. Give me a break,” he said at his event in Manheim, Pennsylvania, mimicking a stumble after he was done.
“She’s home resting right now, she’s getting ready for her next speech, which is going to be about 15 minutes and it’s going to be in two or three days,” he was quoted as saying by media reports.
When Ms Clinton famously collapsed at the 9/11 memorial, from what her doctor suggested was an episode of walking pneumonia, Mr Trump had stayed quiet. He had even wished her well.
But as his campaign has hit a rough patch, he has dispensed with any such magnanimity.
A few days ago in Iowa, he made fun of her for the fall, saying Ms Clinton takes “all those days off” and then “she can’t even make it to her car”.
On Saturday night, he actually acted out his taunting.
The Republican has said he plans to be “even nastier” about former president Bill Clinton’s affairs to “unnerve” Ms Clinton in the next presidential debate. “She’s nasty, but I can be nastier than she ever can be,” he had said.
Last year, Mr Trump had mocked a journalist’s physical disability during a campaign rally, drawing rebuke from many.
Mr Trump had berated New York Times investigative reporter Serge Kovaleski for his recollection of an article he had written a few days after the 9/11 attacks.
Mr Trump had mock Mr Kovaleski’s physical condition. The reporter had arthrogryposis, which visibly limits flexibility in his arms.