Just starting boxing late in life and his fighting style requiring lots of movement to be effective. It's a young man's game below Heavyweight.
Probably something to do with his age, 55 fights and having been a pro for 18 years, it catches up to everyone sooner or later.
His style obviously, he lacked basic boxing fundamentals and relied on his reflexes, springing in and out and lunging, as soon as one thing goes the rest follows.
Years of using his legs in very competitive sports that are hard on your lggs, cycling, Soccer and his style of Boxing are enough to take a toll on even the most fit person. They just finally wore down on him.
He was getting old, but it was that fall in the 12th round of the Chavez Jr fight that messed up his leg.
Dinamita is having knee issues, difference is he doesn't rely on hopping around like a frisky rabbit to deliver his punches and spring back out of the danger zone, Martinez could have been seriously damaged if he'd gone in with Golovkin like everybody wanted, at least Cotto put him out of his misery without too much blood being spilled.
Sadly, it was the injury he had during the Chavez Jr. fight. He knee was never fully healthy again after his biggest win. :/