Dwight Clark says he has Lou Gehrig's disease and suspects playing football might have caused the illness, according to news reports following Clark's announcement on his personal web site late Sunday night.
Weakness in Clark's left hand in September 2015 made him think something was wrong.
'While I'm still trying to wrap my head around the challenge I will face with this disease over the coming years, the only thing I know is that I'm going to fight like hell and live every day to the fullest, ' Clark wrote.
He's lost significant strength in his left hand and also has weakness in his right hand, midsection, lower back and right leg. He said he is unable to walk or pickup anything over 30 pounds.
While Clark said the disease "seems to be progressing more slowly than in some patients", it is already showing its effects on him.
After his playing career, Clark went on to serve as a team executive for San Francisco, before taking over as general manager and Director of Football Operations of the Cleveland Browns from 1999-2002. But I certainly suspect it did, ' wrote Clark.
Before the David Tyree catch in Super Bowl XLII and before Julian Edelman's memorable grab in Super Bowl LI got their reputations as conceivably the two best catches in all of Super Bowl history, there was one other catch that would always and will always be mentioned in the pantheon of famous National Football League post season plays.
A two-time pro bowler, the wide receiver is best known for "The Catch" that carried the 49ers over Dallas in the 1982 NFC Championship game.
The ALS Association describes the ailment as "a progressive neurodegenerative disease that affects nerve cells in the brain and the spinal cord".
Clark, who played all nine seasons of his career with the 49ers, thanked his friends for their support and released a series of remarks from his former teammates about his diagnosis. "I have ALS, also known as Lou Gehrig's disease". Kelly. She has been my rock. "I didn't realize at the time that people would keep talking about it".
San Francisco CEO Jed York said in a statement he was "deeply saddened" by Clark's diagnosis. "Rarely does a day go by when I'm not asked about 'the Catch, ' when we were able to get past the Cowboys and go on to win our first Super Bowl". Right now, I've got work to do. "My ultimate hope is that eventually I can assist in finding a cure for ALS, which disrupts the lives of so many and their loved ones".