Leg pain is common in children who are growing and participating in athletics. But how can you tell the difference between muscle fatigue and a true injury? 

"Many mild aches and pains caused by muscle fatigue or deconditioning resolve on their own over time and comfort measures such as gentle massage, stretching, and ice can help," said Janesville SSM Health Sports Medicine and Orthopedics provider Dr. T. Mark Roman. 

Parents should seek medical care when the pain is in only one leg, the pain continues into the morning or daytime, the child is limping or won’t bear weight.

“It is also important to be seen when there is associated swelling, redness or warmth around a joint, and if the pain comes with a fever, rash or weight loss,” Dr. Roman said. 

Early recognition of the signs of injury can help prevent complications and ensure that young athletes can safely return to the activities they enjoy, like Girls on the Run. 

What are growing pains

Growing pains are most common in children ages 3 to 12. Despite the name, they are not actually caused by growth. Instead, they are related to muscle fatigue, deconditioning and increased physical activity.  

These “growing pain” aches often affect the thighs, calves, shins and areas behind the knees. Children often describe them as: 

• Aching, throbbing, or cramping pain in both legs 

• Pain that comes and goes, often developing in the late afternoon, evening or waking the child overnight, with improvement by morning 

• Discomfort that occurs after especially after active days 

When pain may signal an injury

Pain caused by an injury often follows a different pattern than growing pains.  

One common example of injury is a stress fracture, which is a small crack in a bone caused by repetitive activities such as running, jumping, or intense training. 

Often called “overuse injuries,” stress fractures tend to occur at the junction of bones, muscles and tendons. They are common in the leg, ankle and foot.

Key risk factors for stress fractures include training errors with rapid spikes in distance, intensity or hard training surfaces. Nutritional deficits and inadequate recovery periods with lack of rest days (or poor sleep) can also play a role. 

Signs that may indicate a stress fracture injury include: 

• Pain in a localized or specific area, often on one leg, that is tender to touch

• Sharp or aching pain that starts during a run and eases with rest at first - then progresses earlier in each run and lingers with walking or at rest

• Limping or difficulty moving that interferes with participation in activities 

"Stress injuries in runners occur when repetitive training loads outpace the bone’s ability to repair and rebuild itself,” Dr. Roman said.

Children who are experiencing muscle fatigue should take a short break from their activity and get quality rest.  Injury symptoms should be evaluated by a health care professional. 

Growing pains may be common, but ongoing pain is never something to ignore. If your daughter is experiencing discomfort that's affecting her ability to run, play or participate in Girls on the Run or other activities, the sports medicine experts at SSM Health are here to help. Request an appointment today to get answers, support recovery and keep her moving safely.