NFL concussions

NEW YORK, Dec. 3 (UPI) -- The NFL issued additional rules concerning players returning to the field after suffering a concussion.

Several high-profile NFL careers -- and probably hundreds of careers from players not as famous -- have been shortened because of concussions suffered during collisions between football players and severe falls on the field.

Recent studies suggest that even players on lower levels -- high school age and younger -- could be affected. And the accumulative effect of years of such hits can be debilitating.

NFL Commissioner Roger Goodell revised league policy regarding concussion with a statement Wednesday that advises players who suffer concussions shouldn't return to a game or practice for at least that day and shouldn't be allowed to return to the field at all until "he is fully asymptomatic."

It also called on players "to be candid" about any symptoms. Players, many battling for highly competitive positions on their teams in a league where the average career is 3 1/2 years, are notorious for downplaying injuries and coaches, looking to have their best players on the field, have been known to overlook suspected problems.