Former NHL player Steve Ludzik has been battling Parkinson’s disease for over a decade. He believes the constant pounding from playing hockey led to the disease.

Ludzik, 52, played with the Chicago Blackhawks from 1981-1990. He suffered at least six concussions in his career. But the number is likely higher because back then “you never said anything because you wanted to keep your job,” says Ludzik.

Today Ludzik is speaking up. “I know in my heart of hearts [Parkinson’s] was caused by taking shots to the head,” he says.