Tim Green first noticed the symptoms about five years ago.
The former NFL player, whose strength was a job requirement, suddenly found his hands weren't strong enough to use a nail clipper. His words didn't come out as fast as he was thinking them.
"I'm a strange guy," Tim says. "I get something in my head and I can just run with it. I was really afraid I had ALS. But there was enough doubt that I said 'alright, I don't. Let's not talk about it. Let's not do anything.'"
Denying pain and injury had been a survival strategy in football.