Kids and Sports: How Much Is too Much?

By Paul E. Hughes, M.D.


 

Sports participation in this country by both boys and girls has increased progressively over time. As the popularity of sports has increased so has the idea of year-round sports in which a child can participate in a single sport of choice all year rather than seasonally. With increased participation in one particular sport, there is less down time for recovery from repetitive stresses such as throwing, jumping, twisting, or running. Our children are putting themselves at risk for overuse injuries as their bodies are placed under repetitive stresses at a time when their musculoskeletal development is vulnerable. The open growth plates of growing bones become more susceptible to stresses particularly during growth spurts. With little or no time to heal or recover, inflammation, pain, and deformity can occur about the joints of the knee, shoulder, elbow, foot, ankle, and spine among other joints. Inflammation of the growth plates or apophysitis is relatively common among children who are active and suffer from conditions like Osgood-Slater’s (knee) or Sever’s disease (calcaneus).

Participation in sports is healthy and should be encouraged. Sports promote a healthy and active lifestyle at an early age, which we hope children will carry into adulthood. Children who play sports can show improvement in social, psychological, and physical skills. They do better academically on average when compared with children who choose not to participate in sports. Between the ages of 10 years and 18 years of age, adolescents build bone mass that must last for a lifetime, and weight-bearing exercises, such as running and jumping, help make the bones stronger. However, participation in sports also means an increase risk of injury; 3.5 million children ages 14 and under get hurt annually playing sports or participating in recreational activities. Each year there are more than 700,000 reported emergency room visits for children ages 14 and under with sports-related injuries.1

Endurance Athletes. Both male and female endurance athletes risk overuse. Stress fractures of the lower extremities are relatively common and should be diagnosed and treated early to prevent overt breaks and displacement. Treatment of stress fractures may include rest, immobilization, and nutritional considerations. Endurance athletes are known to have decreased levels of sex hormones, which can lead to bone loss. Sports that emphasize low body weight, such as distance running, gymnastics, skating, and cycling put children at high risk. Females who stop menstruating for more than six months or delay onset after the age of 16 years old can have absorption of the calcium stores in their bones. Premature osteoporosis, or bone loss, may be irreversible, and young athletes who become osteoporotic have increased risk of stress fractures during their athletic training and fractures later in life. Calcium intake for an adolescent athlete should be increased to at least 1500 mg per day to protect male and females against stress fractures. The calcium stores that build up are maximized by around the age of 20 years of age.2

 

Gymnastics

Gymnastics, a common year-round sport, can cause too much strain on the growing bones of children. Studies have shown that gymnasts are at increased risk for spine, elbow, and wrist injuries. Spondylolysis, which is a stress fracture of the pars interarticularis of the lumbar vertebral body, occurs commonly in gymnasts but can occur in any sport that places the athlete in hyperlordosis or back extension. This fracture can lead to displacement and slipping of one vertebral body over the other leading to spondylolesthesis. The symptoms of this disorder can range from nothing to severe back or leg pain and hamstring tightness. The treatment includes rest, cessation of sport, bracing, physical therapy, and even surgical intervention if symptoms persist. The earlier spondylolysis is detected the more likely it will heal with proper treatment. Injuries to the distal radius growth plate are prevalent in gymnasts. One study showed there are radiographic changes present in adolescent gymnasts at a rate of 50 percent regardless of evident wrist pain. This is more evidence that the physiologic changes occurring during growth spurts place the athlete at risk with repetitive stresses.3

 

Baseball/Softball

The amount of throwing and pitching involved in baseball and softball can place a child or adolescent at risk. The traditional inning counts used in Little League and other youth baseball leagues may not be an effective way to prevent the overuse of a pitcher’s arm during the season. Overthrowing can place an athlete at risk for stress to his or her growth plates, tendons, muscles, or ligaments about the shoulder and elbow. Proximal humerus apophysitis, or Little Leaguer’s Shoulder, occurs when the stresses of throwing overwhelm the growth plate or physis causing increased absorption of bone and pain. Pain is the most likely symptom and radiographs of the shoulder may show widening of the physis in comparison with the contralateral side. This is best treated by rest. Little Leaguer’s Elbow is a wastebasket term for multiple disorders that can occur in youth throwers. Apophysitis can occur at any of the ossification centers of the elbow. Osteochondritis Dissecans and Panner’s disease of the capitellum is characterized by underlying bone absorption, or osteonecrosis, caused by the repetitive compression stresses to the lateral aspect of the elbow. Tension injuries to the medial aspect of the elbow can occur during throwing and include tendonitis or ulnar collateral ligament (UCL) injury. If the continuity of the UCL is disrupted, reconstruction or repair is likely needed if the athlete wishes to continue to pitch or throw effectively. Not enough research has been published concerning what the morbidity may be later in life with these overuse stresses on the arm. It is likely that with significant joint involvement, particularly in the elbow, contractures or arthritis may result. To prevent these injuries some have proposed that a pitch count be strictly enforced for each age level. Throwing in pain should be discouraged because this is the first symptom of a problem. Cessation of throwing is the first part of treatment for elbow and shoulder injuries. Radiographs may be ordered initially or deferred as clinical symptoms dissipate. MRI may be of use to evaluate the joint and growth plates to stage disease or plan possible surgical intervention. If an osteochondral defect is not detected early, it may be too late for possible surgical fixation or other treatments that may help prevent permanent morbidity.4

Knee Injuries. Knee injuries are common among children who are physically active. Patello-femoral pain syndrome is one of the most common injuries that a sports medicine physician will see in his or her office. “Runners Knee,” as it is also known, usually presents as anterior knee pain particularly with bent knee activities. It affects more girls than boys and is usually caused by overuse of the lower extremities. After adolescence female athletes have a larger quadriceps angle than males, which results in a more lateral force on the patella during quadriceps contraction. This can result in subluxation or lateral tilting of the patella causing irritation of the underlying cartilage. Treatment includes rest, stretching, and strengthening of the quadriceps either done individually or under the supervision of a physical therapist. If pain persists after such treatment, surgical intervention can be considered.5,6 Many studies show that female athletes are at a three to five times greater risk for an ACL tear than their male counterparts. This is thought to be a multifactorial case for this risk. Women are thought to have anatomic differences in pelvic structure and lower extremity alignment (larger quadriceps angle), a smaller femoral notch, and smaller ligament. Strength imbalances between the quadriceps and hamstrings have been suggested with weaker hamstrings, which can be used to protect the ACL during twists and landings. The ACL in females appears to have more laxity than the ACL of males. Hormonal differences between girls and boys may explain the increased risk in females. Cutting, jumping, and twisting sports, such as soccer and basketball, are notorious for ACL injuries in females. To help lower the ACL injury risk, studies have shown that female athletes who have under gone neurophysiologic training can reduce the risk of ACL injuries compared with control groups. This involves stretching and strengthening of the quadriceps as well as practicing landing mechanics.5,6

 

Sports Physical

A pre-participation physical exam, which is commonly required, gives the physician the opportunity to review the child’s health and give advice on how to stay safe and help prevent injuries. This exam helps identify athletes at risk for injury and can provide athletes and their parents with valuable information to help them exceed safely in their sport. This can be done by advising in nutrition intake and avoiding potentially harmful supplements or even steroid use, which is on the rise in high school athletes. The pre-participation sports physical examination may be the only time many teens see the doctor and thus may be one of the only chances for a child to be advised about maintaining a healthy lifestyle.

It is important to remember that children are growing and any stresses that are too much or too often can result in permanent changes to their musculoskeletal development. Pain is the most common symptom and should never be ignored, and no child should ever play in pain. Proper adult supervision is important to protect our children from overuse injuries.

For more information about preventing sports injuries, go to the American Academy of Orthopaedic Surgeons’ Web site at http://orthoinfo.aaos.org or call 1-800-824-BONES. 

  Dr. Hughes is practices sports medicine in San Mateo.

 

References:

1. National SAFE KIDS Campaign (NSKC). Sports Injury Fact Sheet. Washington (DC): NSKC, 2004. (www.safekids.org)

2.  Voss, LA, Fadale, PD, Hulstyn, MJ. Exercise-Induced Loss of Bone Density in Athletes. Journal of the American Academy of Orthopaedic Surgeons. 6:349-357, 1998.

3. Teitz, CC, Hu, SS, Arendt, EA. The Female Athlete: Evaluation and Treatment of Sports-Related Problems. Journal of the American Academy of Orthopaedic Surgeons. 5:87-96, 1997.

4.  Hughes, PE, Paletta, Jr., GA. Little Leaguer’s Elbow, Medial Epicondyle Injury and Osteochondritis Dissecans. Sports Medicine and Arthroscopy Review. 11:30-39, 2003.

5. Hewett, TE et al. The Effect of Neuromuscular Training on the Incidence of Knee Injury in Female Athletes. The American Journal of Sports Medicine. 27:699-706, 1999.

6. Miller, MD et al. Review of Sports Medicine & Arthroscopy, 2nd edition. Saunders. 43-49, 60-65, 2002.