The largest group, 29 percent, were paralyzed or partly paralyzed by stroke, according to the survey by Anthony Cahill of the University of New Mexico and colleagues.

Spinal cord injuries affected 23 percent, the telephone survey of 33,000 people found. The study was paid for by the Christopher and Dana Reeve Foundation, set up by the actor who paralyzed in a horse-riding accident in 1995 and died in 2004.

"Thirty-sex percent of those who reported being paralyzed said they had 'a lot of difficulty' in moving, while 16 percent said they were completely unable to move," the researchers wrote.

"Household income for those who reported being paralyzed is heavily skewed towards lower income brackets and is significantly lower than household income for the country as a whole as reported by the United States Census," they said.

Reuters