Flat Feet In Children

We usually speak of the flat foot when there is a decrease in the height of the longitudinal arch of the sole of the foot. In general, it is accompanied by a deviation of the heel outwards (what we call the valgus thallus) and therefore is usually called the flat foot-valgus.

In the child, there are basically two types of flat foot: The flexible flat foot and the rigid flat foot.

The flexible flat foot is characterized by being a foot with a normal skeletal structure but with a lot of flexibility in its joints. Therefore, when the child stands up and supports his weight, the bridge sinks and the heel deviates outward. However, when we do it on tiptoe, the bridge reappears, and the heel is placed corrected inwards. This is the most frequent type of foot in the child and is considered a normal situation during the first years of life.

The rigid flat foot is characterized by abnormal junctions between the bones of the foot. This causes a deformity with the lower height of the longitudinal arch and a deviation in the valgus of the heel. When the child stands on tiptoe, the posture of the foot does not change because mobility is blocked by the union between the bones. This situation is definitive and does not change with age.


Most children under the age of 5 usually have flexible flat feet. In addition, during the first two years of life, there is usually an accumulation of fatty tissue in the area of the longitudinal arch that increases the appearance of a flat foot. Normally the height of the longitudinal arch increases progressively in the first years of life; towards the age of 10, it presents a normal standing appearance, and in adolescence, it has just been completely formed.

However, there is a wide range of normality in terms of the height of the longitudinal arch. In general, girls usually have a somewhat more pronounced bow than boys. And in fact, up to 20% of the population never develops a clear longitudinal arch and has painless and functional flexible flat feet throughout life. Therefore, we currently consider flexible flat foot as a variant of normality.

However, a very pronounced flexible flat foot causes difficulties for footwear, friction on the inner part and even pain with physical activities. This symptomatology usually appears from the age of 10 and especially in adolescence because the mechanical load of the foot increases due to the greater weight of the body and that they usually do more physical activity.

The rigid flat foot by abnormal bone joints does not improve during growth and from the age of 10 can cause discomfort, often in the peroneal tendons (behind the fibula in the ankle) since they contract when trying to move joints that are rigid by the bone union. In addition, this bone junction hinders the foot’s ability to adapt to terrain irregularities, and patients often have repeated ankle sprains. Therefore, before a child with repeated sprains, it should be studied that there are no bone alterations in the foot.


The exploration is very simple. You should stand behind the child and observe how he supports the feet. If you observe the absence of a longitudinal arch and a heel that is very deviated outwards, it has a flat-valgus foot.

Then you must tell him to stand on tiptoe. If, in doing so, the longitudinal arch appears and the heel is corrected and placed inward, it is a flexible flat foot that should not worry you. If when you tiptoe, no longitudinal arch appears and the heel is not corrected, it is probably a rigid flat foot, and you should consult with the pediatric orthopedist.


In general, we consider that flexible flatfoot does not require treatment. The use of insoles has proven not to be effective in causing an increase in the longitudinal arch, but its effect is the opposite since increasing the rigidity of the sole of the footwear hinders the stimulation of development of the internal muscles of the foot, and its use is associated with persistence of flat foot. In general, it is recommended to perform activities that develop the intrinsic internal musculature of the foot, such as walking on tiptoe, walking on the sand of the beach or walking at home barefoot (or with non-slip socks).

In cases of the very accentuated flexible flat foot, with pain or difficulty with footwear, there are several reconstructive surgical options. The simplest is to place rigid support between the talus and calcaneus bones that prevent the sinking of the longitudinal arch and the valgus deformity of the heel. Usually, this support is maintained for a couple of years and then removed. In very severe cases, there are other more complex reconstructive techniques.

In cases of the rigid flat foot, little symptomatic is usually sufficient with rehabilitative treatment that reverses the contracture of the peroneal musculature. If there are very repeated sprains or pain that does not subside with rehabilitative treatment, surgery for resection of the abnormal bone junction should be considered.