Bow legs on the baby


The term bow legs is explained by the appearance of the legs in the frontal plane, i.e. when you look at the standing or lying child from the front or back. Bow-legs in babies are generally not a bad thing. They belong to the physiological (natural) Course of development in addition. In some babies the bow legs are more pronounced than in others - nevertheless, even with these babies it can be a complete "Outgrowth" come.

Since there can of course always be an illness-related background with bow legs, it is important that in the course of the U examinations care is taken. In this case, the task of the orthopedic surgeon or pediatrician is to determine whether the course is normal or abnormal. With bow legs in babies that do not grow together by themselves, can do with conservative (non-operational) and operational measures to be helped. The prognosis is very good.


The medical name for bow legs is Genu varum. It describes an axis deviation of the knee from the normal (physiological) Leg axis. Normally the center of the knee joint is exactly on a line between the Center of the hip joint and the Center of the ankle. In a baby with bow-legged legs, the center of the knee joint is no longer on this line, but wider Outside (lateral). If you were to connect all three center points with each other, you would get an angle that would be less than 180 ° inwards (pointing to the other knee) - together with the other knee, a "O“Arise.

Bow legs when standing

Parents often first notice their baby's bow legs when the child begins to stand. This is mainly due to the fact that bow legs are particularly eye-catching when the feet are held together. This is more the case when standing than when lying down. But it does exist no reason to worry. The development of the bow legs in babies is quite normal and in most cases they grow together until 3rd year of life.

Many parents fear that getting their baby up or down too early could put stress on the joints and lead to bowlegs. The general rule here is that the baby's body knows best when it is ready. So when the child is by itself begins to pull itself up and to stand, this shouldn't be a problem for the knees. However, parents shouldn't stand their babies on their feet too often or for too long if they haven't already own standing attempts have dared.

Bow legs when running

When you run, your bow legs behave in the same way as when you stand. When the child starts to walk, bow legs are quite normal and in most cases they have no disease value. They even help with the first attempts at running as they increase the gait stability and thus more safety to lend.
In the course of development, the bow legs usually go back further and further and even become Knock knees in toddler ageuntil they should be straight again around school age.


In the natural development process, bow legs are quite normal in babies

The most common cause of bow legs in toddlers is normal growth process. In babies, parts of the bones are still made up cartilage and are not yet completely ossified. In the course of growth and ossification, the legs are raised to the Running and standing prepared. The angle of the thigh changes (Femur) and tibia (Tibia) to each other.
However, especially with very pronounced forms, a pathological (illness-related) Cause to think.

A Vitamin D deficiency can lead to demineralization, i.e. softening of the bone structure. A resulting one plays a role Calcium deficiency a central role. This can be quickly recognized by a laboratory test and remedied by administering calcium. In paediatrics this disease is called rickets is prevented by general administration of vitamin D from the 2nd week of life.

Another rare cause is that Blount syndrome to think. This is a Deformation of the tibia due to premature closure of the inner growth plate.
Also to be excluded are the Vitreous bone disease (Osteogenesis imperfecta) and also Osteochondromas (benign cartilaginous tumors).


The symptoms are externally award. Due to the changed angle between the upper and lower legs, both legs of the child look as if they were a "O" to form. This can sometimes look very concise and understandably worry the parents. But since this Part of the natural development process is must with no permanent damage be expected.

However, if the bow legs persist beyond the physiological phase, further symptoms can emerge in the musculoskeletal system.

On the one hand, the O-position increases the load on the Inner meniscus (the cartilaginous coating of the knee joint surface on the inside). In the long term this can lead to (premature) Osteoarthritis in the knee joint to lead.

It can also lead to so-called Buckle feet come. The insides of the feet are lowered inwards and downwards. In this way, the children try to compensate for the walking on the outside, which is caused by the bow legs.

Read more about here Knuckle feet in children

It can continue to Bad posture in the upper body come. This occurs above all if there is only one-sided persistence of the bow legs.
This creates a Pelvic inclination with a depression on the side with the bow leg (because here the leg is shorter due to the curvature). This can be a Scoliotic incorrect posture of the spine condition. By this is meant that the spine has a curvature, like a Scoliosis which can be corrected by correcting the inclined pelvis - in contrast to real scoliosis.


The diagnosis is based on physical examination and imaging (e.g. X-ray image) instead of. The pediatrician often recognizes how strong the bowlegs are from the lying or standing child.

This is an interesting possibility that also allows parents to recognize the progression Draw the contours of the legs of the baby on a mat or one Photo documentation in the course. This enables the parents to see whether the expression of the bow legs is getting stronger, weaker or stays the same.

The doctor can also squeeze the baby's inner ankles and the Distance between the knees measure up. With the help of tables, the extent of the bow legs can be determined.

As a further diagnostic measure, a X-ray image of the legs be made. Here the Angle from thigh to tibia to be determined. In addition, the Degree of maturity of the bones be assessed.


In most of the cases, therapy is not necessary due to the normal developmental process. However, if the bowleg position is very pronounced and does not develop back to the age of 3 as expected, then the use of shoe insoles can be used. These are deposits that are shaped like a wedge. This wedge is pushed under the outer edge of the foot. This raises it, and the knee is turned towards the inside in a physiological (normal) Axis tilted. The height of the wedge depends on how strong the bow legs are.
In addition, the corresponding muscles can be strengthened with physiotherapy.

In very pronounced cases, surgery can be carried out. This is indicated when it is foreseeable that the knee joint will not straighten naturally and insoles will not achieve sufficient results either.

The measure used in this case is the corrective osteotomy. A wedge of bone is cut out from the outside of the tibia head. This makes the leg shorter on the outside and the knee tilts outwards so that the knee comes into a more horizontal position.
Alternatively, the bone could also be spread open on the inside - here, too, the outside of the knee tilts downwards (caudal).

Read more about this at:

  • Therapy for bowlegs
  • OP on bow legs


As already described above, the prognosis is in the majority of cases in babies very goodas it is a natural ripening process of the musculoskeletal system. Even in the second year of life, the bow legs are without disease value. in the 3rd year of life usually finds the Straightening the bow legs instead.

In the further course there is also often a training of Knock knees (Genu valgum). In the course of time, this status also grows and most children have until 10 years of age a straight leg axis.


As a prophylactic, parents and doctors can contact the physiological (normal) Do not do anything bow-legged. The only starting point here is the course too observe and to go to the doctor if there are any abnormalities disease-related changes to recognize.