James Harrison (left) uses Unequal Technologies padding to help protect his head, Michael Vick to protect his ribs. (Jason Cohn / AP)

Pittsburgh Steelers linebacker James Harrison is perhaps better known for the physical harm he inflicts on others, but his hard-hitting ways have exacted a toll on his own well-being, too.

Estimating that he has had “double-digit” occurrences of concussion-like symptoms, Harrison added another layer of padding to his helmet, with positive results. “I haven’t seen any spots or had any blackouts,” Harrison said (via the Associated Press).

Harrison and about a dozen teammates (as well as other NFL players) are using padding created by Unequal Technologies, the company that guaranteed its flak jacket would shield the tender ribs of Philadelphia Eagles quarterback Michael Vick. The military-grade Kevlar padding weighs about 3-to-4 ounces and, Harrison says, “To protect my head, I’d take a pound more.”

Harrison has had his issues with Commissioner Roger Goodell in the past over what constitutes a legal hit and has been fined and suspended. “The league is mandating next year that we wear thigh and knee pads,” Harrison said. “I don’t know how many people’s career has been ended on a thigh or knee bruise. We have guys now that are 30, 31 years old that are having to quit the game because they have severe headaches … I think you should be focusing more on [the helmet] than knee or thigh pads.”

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