Dr. Greene's Answer
Gravity and muscle-use patterns sculpt our bodies over time. Most children begin life with moderate in-toeing. When a child begins walking, both the femur (the large bone in the thigh) and the tibia (the large bone in the calf) undergo a gradual process of external rotation. This remodeling generally continues for 6 to-12 months after the child has been walking fully. If an internal or pigeon-toed gait of a significant degrees persists beyond this point, (/ \) a ‘torsional deformity’ exists. Torsional deformities are the result of hindering the normal maturational process of external rotation. This hindrance is most commonly genetic, but can be caused by the environment, such as persistent sitting in the reverse tailor or W position (this is the opposite of Indian-style (tailor position), the child sits with the knees bent and the legs angled outward rather than crossed).
A torsional deformity can occur at the foot, the tibia, or the hip. It commonly occurs at a combination of these sites. In-toeing caused by the foot itself is called metatarsus adductus.
A doctor evaluating a child’s in-toeing will do several things. First, she may look at the bottom of your son’s foot while he is lying on his stomach. If the outside edge is curved inwards (convex), he has metatarsus adductus. If the foot is flexible, and the curve can be straightened, this needs no other treatment than gentle stretching exercises that your doctor or a physical therapist can demonstrate. If the forefoot is rigid, and cannot be straightened, the doctor may recommend seeing an orthopedist to evaluate him for casting or, rarely, surgery.
Next, the doctor may examine the knees and ankles. While your son is relaxed and lying on his stomach, with his knee and ankle each at 90 degrees, the doctor will imagine a line from the second toe to the middle of his heel. If the angle between this imaginary line and the line formed by his thigh, when looking from above, represents more than 10 degrees of in-toeing, he has internal tibial torsion. The normal tibial angle in older children and adults is 10 to 20 degrees of out-toeing. Internal tibial torsion usually corrects itself in the first 6 to12 months of walking. If the internal tibial torsion alone is 40 degrees at any time, or persists beyond this timeframe, the doctor will usually recommend that you see an orthopedist for evaluation and possible treatment.
Torsional deformity at the hip, called internal femoral rotation or femoral neck anteversion, is difficult to assess at home. Your pediatrician can demonstrate this finding to you if it is present. Sitting in the tailor position, formally known as Indian-style, can help improve the condition.
Whatever the cause, discuss your son’s in-toeing with your pediatrician. Be sure you both watch him walk during his 15-month and 18-month well-child examinations. Between doctor’s visits, look out for any signs of pain, swelling, or limp and seek medical care if any of these symptoms develop. You’ll also want to see your doctor if your child experiences frequent tripping, difficulty wearing shoes, or any worsening of the in-toeing.
For most children, in-toeing at your son’s age is part of the dynamic, flowing design of human development. Most likely you will watch together as the in-toeing resolves spontaneously. If not, you will be attentive to provide your son the appropriate help to get his normal external rotation back on track.