Football and pain may go hand-in-hand long after players leave the field and even the game, according to research at the Washington University School of Medicine in St. Louis. The study found retired National Football League players misuse painkillers at higher-than-average rates.

In a release about the findings, the researchers say "the brutal collisions and bone-jarring injuries associated with football often cause long-term pain, which contributes to continued use and abuse of painkilling medicine."

The research is published online in the journal Drug and Alcohol.

ESPN says it commissioned the study, which also received funding from the National Institute on Drug Abuse, after doing a story on former Philadelphia Eagles defensive tackle Sam Rayburn, who was open about his addiction to the painkiller Percocet. ESPN says it searched scientific literature to see if his experience was unusual, but could find nothing quantifying or comparing the use of painkillers by former pro football players to the general public.

The researchers queried 644 former NFL players who retired from football beween 1979 and 2006. It found 7 percent currently use painkilling opioid drugs, quadruple the rate of use in the general population. Drugs in the category include morphine, Vicodin, codeine and oxycodone, they noted.

Principal investigator Linda B. Cottler, PhD., professor of epidemiology at Washington, said more than half had used and misused opioid drugs during their NFL careers.

"Those who misused the drugs during their playing days were more likely to continue misusing them after retiring from football," the release said. Cotter noted that it's not clear whether retired players became dependent on the drugs, although it is clear that "retired NFL players continue to live with a lot of pain."

The study found about 47 percent of retired players have three or more serious injuries in their NFL careers and 61 percent said they had knee injuries. More than half said their careers were ended by injuries.

In a 2002 interview with the, Deseret News, NFL Hall of Famer and Super Bowl MVP Joe Namath said he developed osteoarthritis at age 23 and that in the years since he battled bad knees (both needed reconstructed), slight compression of the sixth and seventh vertebrae in his spine with violent muscle spasms and "burning and throbbing at the base of his thumbs that left him screaming once when he gripped his steering wheel." Such injuries, he said, were common among players and the effects lingered.

Injuries in sports occur often enough that lists injuries and pain associated with sports alphabetically in a quick-read reference. The section dedicated to football injuries includes everything from ankle sprains and turf toe to concussion, herniated disks and such shoulder injuries as torn rotator

Comment on this story

It's not the only interesting, even provocative research about pro sports and pain out this week. A study quoted this week in The Telegraph shows that women athletes may be tougher than men. Or, as author Andy Bloxham puts it, "Scientists claim to have proved that women in sport play through harsher pain thresholds than men and pick up the same injuries, but struggle through. Experts believe the discrepancy is down to psychological differences in the way the genders process pain, with the women toughening up to 'prove' they can play the game."

Those researchers were from the University of the West of England.