Do you know what flat feet are?

A flat or dropped foot (lat. pes planus) is the shape of a foot with a depressed arch that fully touches the ground. We correlate the valgus position of the heel to the lowered foot. In valgus, the heel is displaced outwards. Dropped feet are more common in youngsters, and in newborns, they can be a natural occurrence due to insufficient development of the foot arches. Read on to learn everything there is to know about the anatomical structure, cause, symptoms, and treatment of dropped feet (operative, footwear, insoles, 3D foot diagnostics…)

What exactly are foot arches?

To grasp what flat (lowered, dropped) feet are, a few anatomical notions must be learned. The foot bones are organized into longitudinal and transverse arches. The arches’ job is to move the feet and transfer body weight and load to the surface. The foot can adapt to different surfaces and sustain changes in stress precisely because of this anatomical structure. The lower leg bones convey body weight to the ankle bone, which then transfers to the heel bone and metatarsal heads. (Metatarsal bones are found in the front of the foot.) Elastic foot arches are formed by stretching the metatarsal bones and the heel bone together. When under heavy strain, such as when standing, the arches are lowered. Because of the lower load, they bend again when sitting. The foot arches are divided into two types: the longitudinal arch (arcus pedis longitudinalis) and the transverse arch (arcus pedis transverseis) (arcus pedis transversus).

Longitudinal foot arch- The medial and lateral sections of the foot arch are split longitudinally (the medial part is located towards the middle of the foot, and the lateral one is at the side). On a healthy foot, the medial section of the longitudinal arch is visible. We can see the points of support on the base by looking at the imprint of the sole. These are the heel, the lateral section of the sole, and the area around the metatarsal bone heads (the part of the sole under the toes). During loading, the lateral part of the arch is lower than the medial part and lies on the base.

The transverse arch of the foot is created by the cuboid, three wedge bones, and the bases of the metatarsal bones and runs through the middle of the foot.

Aside from bones, ligaments, muscles, and aponeurosis all contribute to weight transfer. The lig. plantare longum, lig. calcaneonaviculare plantare, lig. calcaneocuboideum plantare, and plantar aponeurosis are the most significant structures for preserving the arches of the foot close to the bones.

The plantar ligaments and plantar aponeurosis are the most loaded of all the anatomical components discussed, and the muscles at rest have no role in supporting the foot arches. During walking, the muscles conduct foot inversion and eversion. The shift of the sole towards the central plane is referred to as inversion. As an example, consider removing a thorn from the sole of the shoe. The movement of the sole of the foot away from the central plane, as when lifting the outside of the foot, is referred to as eversion.

Flat foot classifications

Flat feet can be classified into three types. The first category includes feet in which the deformity was only at the muscle level. In this instance, the muscles that support the arch of the foot are weak, and the medial section of the arch is stretched. With this degree of distortion, there is a minor deviation of the lateral part of the metatarsal bones and, as a result, the creation of a callus due to increased pressure. The second type of feet includes those with muscle and connective tissue abnormalities. The pressure on the base is equivalent to the pressure on the center and front of the foot, which is not typical. Deformations of the muscle, connective, and bone levels are included in the third group, which includes feet with the most deformation. The metatarsal bones, as well as the ankle bones, fall here, distributing pressure evenly throughout the whole area of the foot. When walking on a sandy beach, for example, the degree of distortion can be seen in the footprint. The impression of completely malformed feet will not have a rounded arch medially.

Dropped foot causes

Sagging arches, commonly in the medial region of the longitudinal arch, induce dropped feet. Standing for an extended period, particularly if the person is overweight, causes the plantar ligaments and aponeuroses to stretch, and the ligaments can no longer support the bones. The medial section of the longitudinal arch is lowered as a result, and the front half of the foot travels laterally. When the stress is removed, such as when a person sits down, the foot returns to its original arched shape in the classic form of a dropped foot. Dropped feet are prevalent among the elderly. Rapid weight increase or long-term load is a significant risk factor. Similarly, when putting weight on the feet, it is critical to pay attention to the footwear chosen. DrLuigi medical footwear conforms to the anatomical features of the foot arches and does not cause additional discomfort due to aponeurosis and ligament stretching.

Because of the fat pads on the soles of the feet, this phenomenon is not pathological in new-borns and babies. All foot arches exist at birth but are not visible until the third year of life.

A dropped foot can be caused by any of the following conditions: cerebral palsy, muscular dystrophy, rheumatoid arthritis, foot or ankle injury, weak Achilles tendon…

Epidemiology

Research shows that from 20% to 37% of the population suffers from a certain degree of deformity, which we could call a dropped foot. In general, the condition is more common in women and children. As many as 20-30% of children suffer from drop foot.

S.J.
12.07.2022.