John Hawkes placed a cushion under one side of his back to achieve the look of Mark O'Brien's distorted spine.
Writer-director Ben Lewin is a polio victim himself. He was researching a semi-autobiographical sitcom when he stumbled on the internet on the story of Mark O'Brien and sex surrogate Cheryl Cohen Greene.
The movie is based on the article "On Seeing a Sex Surrogate", by 'Mark O'Brien (III)', from the May 1990 issue of The Sun magazine.