Ricky Keith, who organizes summer and fall baseball teams for players from ages 12 to 17, is concerned with the number of shoulder and elbow injuries he has seen in recent years.

His Carolina Cubs Showcase teams are designed to teach and display players' skills for college coaches. The various teams play about 60 games each year, and Keith limits his pitchers to 50 or 60 pitches a game. But, he said, more players are getting hurt than in 2004, when he started the program.

Within the past year, a couple of the organization's teenagers have had ulnar collateral ligament reconstruction, a surgical procedure in which an elbow ligament is replaced with a tendon from elsewhere in the body. The procedure is better known as Tommy John surgery, named after former Major League Baseball pitcher John, who was 31 when he had the career-saving surgery.

"You just seem to be seeing a lot more shoulder and elbow injuries," Keith said. "When I played, we had a high school season and then an American Legion season. With showcases, Legion or another summer league, plus fall ball, the older players can play 100 games over the stretch of a year."

Dr. James Andrews, one of the top orthopedic surgeons in the world, says young athletes who play one sport year-round as they try to compete at higher levels are putting themselves at risk for career-ending injuries.

The problem, he says, is overuse.

Overuse injuries, which occur when the body is not given enough time to recover from the wear and tear of constant action, are causing an "epidemic" of injuries among young athletes, Andrews, of Birmingham, Ala., said.

Andrews, who is known for his treatment of professional athletes' knees, shoulders and elbows, has studied youth sports for years.

"Epidemic isn't too strong a word," Andrews said in an interview. "We are having children injured and perhaps out of sports before they ever have a chance to become athletes."

Overuse, which causes gradual damage as opposed to a sudden injury caused by a specific trauma, is responsible for almost half of the 2 million injuries among high school athletes each year, according to the American Orthopedic Society for Sports Medicine and the American Academy of Orthopedic Surgeons.

Dr. Lyle Micheli, the director of sports medicine at Boston Children's Hospital, said 75 percent of young athletes who go to the facility for treatment suffer from overuse injuries, up from 20 percent in the 1990s.

The American Journal of Sports Medicine published in February the results of a 10-year study by the American Sports Medicine Institute in Birmingham that showed that players who pitched baseball more than 100 innings in a calendar year were 3.5 times more likely to be injured. If an adolescent plays more than eight months a year, he is five times more likely to be injured, according to Andrews, who was involved in the study.

The injuries are the result of a system that prepares the genetically gifted to play at the highest levels, but eliminates most players because their bodies cannot withstand such intense activity at an early age, Andrews said.

"Yes, an individual Major League Baseball player specialized and played year-round for years," Andrews said. "But that same amount of play would end most athletes' careers."

Andrews says he performed Tommy John surgery on five patients who were high school age or younger in 1998. He performed the same surgery on 28 children in the same age range in 2008.

The usual cause of the ligament injury is throwing too much, too soon. Throwing a baseball or softball creates powerful forces on the shoulder and elbow, straining muscles, tendons and bones and young arms and shoulders are often not fully developed and can be more vulnerable to damage caused by overuse.

Andrews said children are being encouraged to specialize in one sport and to play it too often without sufficient time to recover following a season.

He said players should never play on more than one team in one sport at a time and emphasizes that parents need to know and observe league limits.

Playing too much

Mike Fox, the University of North Carolina baseball coach, said he regularly sees high school players who have injured themselves through overuse.

"They just try to play too much," Fox said. "There is this belief that you have to play all the time and you have to play with certain people to be noticed. That's not true. Developing players need rest and perhaps while they are resting from baseball, they can have the opportunity to play other sports if they enjoy them.

"Some players are just overdoing it. I'm certainly not an expert on overuse like Dr. Andrews, but I do see players who have overuse injuries."

N.C. State has four pitchers from Florida in its 2009 recruiting class who each had arm trouble as a freshman.

Wolfpack coach Elliott Avent said year-round play might have been a factor.

"You used to hear, it was sort of a joke, that college coaches need to recruit their position players in the South where they play a lot and their pitchers in the North, where they hadn't been pitched to death," Avent said.

"Baseball is a game you need to play to improve, but if you are making the same throwing motion numerous times for 365 days a year, you can see where you can develop a problem."

Trying for limits

The N.C. High School Athletic Association limits high school pitchers to 12 innings during a 72-hour period. But the NCHSAA has no authority over recreation and club teams. Conceivably, a NCHSAA pitcher could pitch 12 innings on Friday and pitch again for a club or showcase team the next day.

"Parents have to be involved in protecting their child," Andrews said. Mike Guerrero of Garner High and Aaron Minger of Broughton High, both certified athletic trainers, said that by the time many athletes, not just baseball and softball players, get to high school they already are showing signs of damage, and not just to their arms and shoulders.

"We had a football player that the neurologist said had the back of a 45-year-old man," Guerrero said. "The player was 17."

Not everyone blames overuse for the influx of injuries.

Mike Lloyd coaches one of the Cubs' Showcase teams and his son Chandler, an 18-year-old senior at Kerr-Vance Academy in Henderson, had Tommy John surgery performed by Andrews last June. Chandler played his senior year at the private school, hitting nine home runs including three in one game, but was not allowed to pitch.

"I don't think Chandler's problem was overuse," Mike Lloyd said. "I coached two pitchers who are playing Double A (professional) ball now, and they threw a lot more than my son did. I just think some kids are going to have it and some aren't."