Many knee and foot problems that parents notice in their infants and young children eventually resolve on their own without treatment. Some problems develop because of the way the legs were positioned in the uterus before birth. Rarely, treatment may be needed.

In flat feet, the middle of the feet, which are normally arched, appear sunken. An infant with normal feet may appear flat-footed because a fat pad appears in the arch of the foot. Flat feet may result when the arch of the foot is unusually flexible (flexible flatfeet). Another cause of flat feet is stiffening of the foot joints that fixes the foot in a position with a flattened arch (tarsal coalition). Tarsal coalition may be a birth defect or result from conditions such as injuries or prolonged swelling.

Usually fat pads and flexible flatfeet cause no symptoms. Sometimes flexible flatfeet cause pain or cramps in the feet. Tarsal coalition may cause pain or cramping. Feet with tarsal coalition are stiff, which can interfere with walking or running.

Fat pads do not require treatment. Flexible flatfeet usually do not require treatment. However, if an older child has pains or cramps in the feet, corrective shoes may be needed. Treatment for tarsal coalition often includes a cast. Sometimes surgically separating the attached internal structures restores mobility to the foot.

In bowlegs (physiological genu varum), the knees appear rotated away from each other. Bowlegs develop because of the way the legs bend to fit in the uterus before birth. Bowlegs develop in toddlers and are considered normal. Usually the only symptom is the appearance of the knees. Usually the condition corrects itself within about a year after the child begins to walk.

In knock knees (genu valgum), the knees point inward. Knock knees most often affect children aged 3 to 5 years. Usually the condition corrects itself by the age of 10 without treatment.

Femoral torsion is curving of the thighbone (femur). With internal femoral torsion, the thighs curve inward. The knees, and usually the toes, point toward each other. With external femoral torsion, the thighs curve outward. The knees and toes point away from each other. Internal femoral torsion develops much more often than external femoral torsion. Children with internal femoral torsion sometimes have abnormally flexible joints and ligaments.

Internal and external femoral torsion usually correct themselves when the child is older and begins to walk. Sometimes, internal femoral torsion is corrected by making sure that the child sits straight. Maintaining a straight sitting position may not be possible until the child reaches school age. In the rare circumstance when internal femoral torsion persists past the age of 10, surgically straightening the bone may be necessary. It can take years for internal or external femoral torsion to improve. Tibial torsion is curving of the shinbone (tibia).

Tibial torsion develops before birth and is very common. In internal tibial torsion, the tibia curves inward, pointing the toes toward each other. In external tibial torsion, the shinbone curves outward, pointing the toes away from each other. Tibial torsion is often noticed during the second year of life when the child begins to walk. The shinbone appears curved but gradually straightens after the child begins walking.