Up to 50 percent of aches and pains your child experiences in his legs after exercise are the result of overuse, says seattlechildrens.org. This type of pain usually resolves after a period of rest and rehydration. However, if your child reports severe or specific pain, such as that occurring in a particular joint or area of the leg, this pain may warrant evaluation and potential intervention by a doctor.
When Not to Worry
Muscle strain and spasm are the primary causes of the pain your child may experience in her legs after play and exercise. This type of overuse occurs with excessive activity, such as jumping. If your child experiences muscle pain lasting one to 15 minutes, it's likely the result of a muscle cramp. Muscle cramping usually resolves with extra fluids, a salty snack and a bit of rest. Just like an adult, your child can play or exercise strenuously enough to cause muscle strain, resulting in pain that could last for several days. If your child has this type of overuse injury, rest until she can resume normal play is generally a good remedy. Your doctor may identify intermittent, harmless pain of unknown origin as a growing pain. Although it's not actually a result of growing, approximately 10 percent of children experience this type of pain, and it's almost never a cause for concern. Finally, If your child reports generalized aches and pains, they may not be related to exercise at all. The pains could instead be the result of illness, such as flu, or even the a common cold.
Synovitis
A common cause of childhood hip pain, synovitis is an inflammation of the hip joint typically occurring in children ages 2 to 5, says St. John Providence Health System Although not directly related to overuse, exercise can potentially exacerbate pain to intolerable levels. One culprit in the development of synovitis is a virus that travels to the hip joint and causes inflammation. If your child reports thigh or knee pain--particularly after having had a viral illness -- watch for signs and symptoms of synovitis, which include walking tiptoed and crying while trying to walk. Other symptoms of the disorder include an unwillingness to walk, a low-grade fever and limping. Although these manifestations may be alarming, they are transient, and the condition usually resolves within one to two weeks, Kids Health says. If you notice your child exhibiting signs of synovitis, however, seek medical attention. Your doctor may want to rule out other potential causes for the symptoms and monitor your child throughout the course of the viral infection.
Legge-Calve-Perthes Disease
At the top of a healthy femur -- the long bone of your child's thigh -- is a ball that fits into the hip socket and makes up the hip joint. Children with Legge-Calve-Perthes disease have impaired blood flow to the hip, which results in degradation of the ball of the femur. Your doctor may suspect this disorder, particularly if your child reports pain in the knee, groin or thigh that worsens during play and exercise and resolves during periods of rest and inactivity. Unless the severity of this condition requires surgery or a special brace to limit movement of the joint, your child can engage in self-limiting play and exercise. Typically manifesting in children ages 4 to 10, Legge-Calve-Perthes disease usually resolves on its own, and injury to the ball of the femur heals. The disorder does not typically recur, according to St. John Providence Health System.
Slipped Capital Femoral Epiphysis
Usually occurring more often in males and during periods of rapid growth -- such as puberty -- slipped capital femoral epiphysis causes the head, or the epiphysis, of the femur to shift backward within the hip socket. Manifestations of slipped capital femoral epiphysis include chronic hip or knee pain. Exercise and normal play, particularly that resulting in falls, exacerbates common symptoms of the disorder. The classic presentation for an adolescent with this condition is limping. The child's leg may appear shorter than the unaffected leg, and it may be turned slightly outward comparatively. To avoid further complications, such as arthritis and limited range of motion of the hip joint, immediate surgery -- typically within one or two days -- is the only intervention. According to the American Academy of Orthopaedic Surgeons, a surgeon usually fixes the head of the femur in place within the hip socket with one or two orthopedic screws to stop the bone from slipping backward.
