"He was a man in very good health," said Kennedy adviser Ted Sorenson told ABCNEWS. "There is no doubt about the fact that he had a bad back, as millions of men do, sometimes it hurt worse than others."
His aides attributed any visible problem to a war injury. When the president rode a cherry picker to board Air Force One, it was just because of a sore back, not the fact he couldn't climb a stair.
In the book, Dallek speculates that the corset Kennedy wore for his back trouble may have made him a sitting target for his assassin, Lee Harvey Oswald. Kennedy's back was ramrod straight, making his head and neck perfect targets when the second bullet — believed to be the one that killed him — struck.
"Of course we'll never know, but if he had toppled over when the first bullet hit, he might have been saved," Dallek said.