How many backs could a back back back if a back back could back back?

"Give it to me straight, doc."
"You'll never walk again."
"But I walked in here. I'm standing right now."
"I never said I was a good doctor. How are you treating your back at the present time?"
"I took a page from the Heath Ledger Book of Pharmaceuticals and Mixology."
"Well, what do you need me for? You're two steps ahead of me."
"I thought you could tell me if I need physical therapy or steroids or whatever."
"You don't need steroids. You already have the strength of 10 men."
"Ten dead men?"
"Yes. Dead or dying."
"Is there anything else you can recommend?"
"Have you thought about getting a pre-owned back?"
"No."
"You know who has a strong back? Horses. Horses do."
"Is it possible to get a horse back?"
"I don't see why not."
"Where'd you go to medical school?"
"Don't change the subject."