Well, I know that Valintino tore his bicep tendon. But that was a while ago. I beleive that would be due to the tremendous stress he was putting on his biceps from his
seo abuse. Now he claims that it wasn't SEOs and that the huge amount of gear he site injected got his arms that big, but if that was the case, you'd see some guys walking around with a bubble ass the size of texas. I beleive he abused SEOs like no other.
If you stretch your muscle too much with anything, there will be a point where it can't take it anymore and will snap.
Macdaddy