My uncle had it, is as active as he can be. One leg much smaller than the other. A positive guy who works hard to do the most he can with what he has. The work his mom made him do as a child...stretching exercises etc...turned out to have helped him get stronger initially but the docs now say those muscles are basically worn out. Broke a hip and a kneecap recently...just wears out faster than normal healthy people I guess. He taught science for 30 years, was a successful guy despite the handicap