With child athletes becoming increasingly competitive and training more rigorous at younger ages, orthopedic physicians are seeing an alarming rise in sports injuries simply from kids overdoing it.

Physicians at a major orthopedic meeting in San Diego said children as young as 4 years old are sustaining overuse injuries such as stress fractures and tendinitis.

“It’s becoming more and more apparent in our care of adolescents and even preadolescents, there is a lot of pressure on young children to do more and more in sports,” Thomas Clanton, team doctor for the NBA’s Houston Rockets, said at the annual American Academy of Orthopedic Surgeons meeting.

“They never get a chance to rest,” said Clanton, who also is a professor of orthopedic surgery at the University of Texas-Houston Medical School.

High-impact sports that include jumping and running - such as football, basketball, gymnastics and soccer - are the worst culprits, experts said. Increasing year-round participation by children is wearing on young bones, they said.

Overuse injuries are becoming more prevalent in part because young bones are not given a chance to recover and as pressure by coaches and parents intensifies, said Mark Myerson, medical director at the Institute for Foot and Ankle Reconstruction at Mercy Medical Center in Baltimore, and president of the American Orthopedic Foot and Ankle Society.

“The pressure from families, school and coaches to perform becomes a massive component in these injuries,” he said.

Panelists included two former chairs of the society, who agreed.

Lack of regulation is a problem that needs to be addressed, panelists said. Few sports have guidelines for time spent practicing for children, although Little League Baseball recently enacted guidelines, including limits on how many games players should pitch in a week, for example.

“In so many of these sports, there is no limit,” Myerson said. “After (grade 10) you are competing all year round.”