Washington, Nov 9 - Gifted young athletes are increasingly under pressure to play only one sport round the year. But a new study has found that such specialization increases the risk of injury.

Researchers from the Loyola University Health System (LUHS) examined 519 junior tennis players and analysed 3,366 matches in junior competitions in the US and found that players who specialized in only tennis were more likely to withdraw from tournaments for medical reasons, typically injuries.

Also, players who had experienced an injury or tennis-related illness during the past year were 5.4 times more likely to withdraw from a tournament for medical reasons.

"Parents, coaches and players should exercise caution if there is a history of prior injury," said Neeru Jayanthi, professor of orthopaedics at Loyola University School of Medicine, who led the study.

"And parents should consider enrolling their children in multiple sports," Jayanthi said.

Volunteers in the study began playing tennis at an average age of six, began competing at age nine and began to specialise at age 10.

Players practised a median of 16 to 20 hours per week, and 93 percent said they competed at least 10 months per year.

Boys are more likely to withdraw for medical reasons than girls, and older teenagers are more likely to withdraw than younger adolescents.

Injuries in young tennis players typically include muscle strains, ankle sprains, hip injuries, knee cap instability, stress fractures in the spine and tendonitis of the wrist and rotator cuff, a LUHS release said.

"But one injury you rarely see in kids is tennis elbow. That's because they learn to hit the ball correctly," said Jayanthi who has studied tennis injuries as a player, coach, physician and researcher.

These results were presented at the international Society for Tennis Medicine and Science World Congress in Valencia, Spain. (IANS)