Since the beginning of time, an injury is something that most professional athletes have had to deal with at one time or another.

Football in particular, is a rough and physical sport, having contributed to numerous injuries over the years. While the majority of those wounded returned sooner rather than never, some are career enders.

The football players included in this slideshow are just a handful of those who've experienced the most horrific ones. Few lucked out and continued on with their career, while others were forced to retire prematurely due to the severity of their injuries. 

Washington Redskins' quarterback, Joe Theismann's career was brought to a screeching halt on Nov. 18, 1985 when he suffered a comminuted compound fracture of his leg while sacked by New York Giants linebackers Lawrence Taylor and Harry Carson. The scene on TV appeared horrific.

In his third year in the NFL, Mike Utley, an offensive guard for the Detroit Lions, injured his sixth and seventh cervical vertebrae, which occurred in a game against the Los Angeles Rams on Nov. 17, 1991. Unfortunately, he later learned that he was largely paralyzed from the chest down, Nonetheless, Utley still managed to flash the crowd the thumbs up signal as he was being taken off the field

The New York Jets' Dennis Byrd was on the receiving end of a brutal neck injury against the Kansas City Chiefs on Nov. 29, 1992. After colliding headfirst with his very own teammate, Scott Mersereau, Byrd broke his C-5 vertebra, leaving him unable to walk. However, after retirement and extensive physical therapy, he would later walk again.

On Sept. 5, 1994, Los Angeles Raiders' running back, Napoleon McCallum's career ended when his left cleat got caught in the ground while he was tackled by Ken Norton Jr. McCallum suffered a complete hyperextension of his left knee, almost to a right angle, tearing three ligaments as well as his calf and hamstring from the bone.

Reggie Brown was a linebacker for the Detroit Lions. He played only 32 games in his young career, sufferinga spinal cord contusion while assisting on a tackle of New York Jets halfback, Adrian Murrell, during the 1997 NFL season. Brown was motionless for 17 minutes, and briefly lost consciousness. CPR saved his life and emergency surgery saved him from being put in a wheelchair.

Steve Young, quarterback for the San Francisco 49ers, suffered many concussions throughout his career and the 1999 season would turn out to be his last. During a Week 3 game against the Arizona Cardinals, the lefty signal-caller was violently sacked by cornerback Aeneas Williams.

Chris Kuper, an offensive guard for the Denver Broncos, suffered a ghastly broken ankle during the last regular season NFL game in 2011. Although he made a full recovery, the image on TV was disturbing.

NCAA collegiate football has also had it’s share of injures, including one that occurred in 2010. Rutgers University defensive tackle Eric LeGrand suffered a severe spinal injury during a game against the Army Black Knights. On a kickoff to Army, LeGrand viciously collided with Malcolm Brown. LeGrand was on the ground for several minutes prior to being carted off. Fortunately, he's since regained movement in his shoulders and sensation throughout his body.