By Jane E. Brody

New York Times News Service

Few parents enroll their children in organized sports with the expectation that they will get injured. Yet children often do get hurt, and sometimes those injuries can sideline young athletes for months or an entire season and may sour them on participating in the future. The effects of sports injuries may even linger into adulthood.

“Injuries are often considered an inevitable part of sports,” according to Dr. ­Terry Adirim, a sports medicine expert who is now a health affairs specialist for the Department of Defense, and Dr. Tina Cheng, director of pediatrics at Johns Hopkins School of Medicine. “However, like other injuries, sports injuries are potentially preventable.”

Reducing the risk of injury, they wrote in the journal Sports Medicine, requires taking into account the physical and physiological differences between children and adults, differences that can leave youngsters more vulnerable to injury. Children have a larger surface area and bigger heads relative to their body size; their growing cartilage is more susceptible to stresses; and most lack “the complex motor skills needed for certain sports until after puberty.”

In a guide to safety for young athletes, the American Academy of Orthopedic Surgeons points out that “children’s bones, muscles, tendons and ligaments are still growing,” which makes them more susceptible to injury. Growth plates, the cartilage at the end of long bones where bone growth occurs, are especially susceptible to injury that could disrupt normal growth.

“A twisted ankle that might result in a sprain in an adult, could result in a more serious growth plate fracture in a young athlete,” the organization emphasized. Also, children lack an adult’s level of coordination, strength and stamina.

Many parents want their children to reap the benefits of sports participation. In addition to socializing with their peers and enhancing self-­esteem, sports participation fosters a child’s overall health and bone density and reduces the risk of overweight, diabetes, cardiovascular disease, depression, risk-taking behavior and teen pregnancy, noted Dr. Cynthia Bella, pediatric orthopedist at Northwestern University’s Feinberg School of Medicine, and co-author of an editorial on youth sports injury prevention in the British Journal of Sports Medicine.

Thus, the goal should be to take whatever measures one can to avoid athletic injuries — or at least minimize their severity — and keep kids in the game. First and foremost, that means parents and coaches must create an atmosphere of healthy competition, with an emphasis on cooperation, self-confidence and good clean fun rather than just winning. Children need to learn how to deal with defeat as well as victory.

Second, all young athletes should strive to be in good physical condition for their chosen sports. That means starting with a pre-­participation sports physical exam that could reveal potential problems, then following a guided conditioning program that entails exercises appropriate for the chosen sports.

Every child should know and obey the rules of the game and always use proper protective gear. Games should start with a warmup to avoid damage to “cold” tissues. Adequate rest beforehand is always important — tired players don’t think clearly or play well — and good hydration is essential throughout the game.

I should also mention the importance of good nutrition. Children who are deficient in vitamin D, for example, are 3.7 times more likely than those with normal levels of the vitamin to suffer a fracture that requires operative repair, Dr. Pooya Hosseinzadeh, pediatric orthopedist at Washington University in St. Louis, reported at a recent meeting of orthopedic surgeons. In her study of 100 youngsters with forearm fractures resulting from low impact (like falling from a standing height), 49 percent were deficient in vitamin D, and half of those required surgery.

In an interview, Hosseinzadeh said, “Children are not getting out into the sunshine enough nowadays, and they’re not consuming enough seafood and fortified milk,” the main dietary sources of vitamin D. When vitamin D levels are low, calcium absorption is impaired and the body takes the mineral from one’s bones to maintain a proper blood level. “The bones get weaker and break more easily,” she said.

Dr. Elizabeth Matzkin, orthopedic surgeon and chief of women’s sports medicine at Brigham and Women’s Hospital in Boston, also emphasized the importance of eating enough. “Energy going in should be adequate for the amount going out,” she said. “If not, bone health can suffer and bone stress injuries can result. You can only build one’s bone bank to age 25. We don’t want kids starting out with too little in the bank.”

Probably the most common injuries among young athletes result from overuse, which causes undue stress on certain body parts, like the tissues in a Little Leaguer’s elbow. Overuse injuries result when a child continually uses the same muscle groups and applies the same stresses to a specific body part, resulting in muscle imbalances and inadequate time for repair.

To avoid such injuries, Matzkin recommends “diversification — playing multiple sports and different positions so they’re not doing the same motions with their bodies over and over again.” She and other experts recommend that children younger than 16 not practice a given sport for more hours a week than their age in years. Children who play the same sport on more than one team in a given season are at increased risk for injury.

Participating in different sports helps youngsters develop “good biomechanics,” which reduces injury risk, Matzkin said.