The arch of the foot is an important structure of the human foot. With the arch, the foot is elastic. It absorbs the impact force of the ground on the foot and locks the midfoot joints, making the foot stiff and better able to propel the body’s activities. Flat feet (flat feet) refer to the absence of a normal arch, or a collapsed arch. It is important to note that flat feet are not the same as flatfoot syndrome, and not all flat feet require treatment. When a person with flat feet has a combination of symptoms such as pain, they are said to have flat feet and may only need treatment. In fact, people with flat feet are very common, while flatfoot syndrome is not. Many people with flat feet, especially children, have no symptoms and do not need treatment. Only a small percentage of children with flat feet may gradually cause changes in their entire body posture, and some flat feet may be combined with abnormalities in the bone structure of the foot, such as the vertical talus and tarsal coalition. In adults with flat feet, there are more women over 50 years old. When adult flatfoot first occurs, the arch of the foot exists in the non-weight-bearing state, and disappears after weight-bearing. At this time, because the mobility of the joints still exists, it is called reversible flatfoot or flexible flatfoot. If there is joint lesion, restricted movement and deformity cannot be reset, it is called rigid flat foot.
Etiology of the foot arch Flat feet can be congenital or acquired. In children, the arch is often formed at the age of 4 to 6 years, and most children and adolescents with flat feet are congenital. Adult flat feet can be a continuation of childhood flat feet or can be secondary to other causes, resulting in a collapsed arch. Symptomatic adults with secondary flatfoot are referred to as adults with acquired flatfoot syndrome. There are many causes of secondary arch collapse such as joint degeneration, trauma, diabetes mellitus, rheumatoid arthritis, neuropathic lesions, tumors, and posterior tibial tendon insufficiency.
Pathological changes can be clinically manifested as 1. Pain is usually located on the medial side of the plantar foot (posterior medial pain), and is aggravated after prolonged standing or walking, and can often appear progressive aggravation. Occasionally, the pain can be located near the lateral ankle joint. This is the result of the collapse of the arch of the foot causing the hindfoot to turn out, followed by the impact of the fibula and the heel bone.
2. Swelling Painful extra-articular swelling, especially at the navicular tuberosity of the foot.
3.Gait abnormality Pain and arch collapse of the affected foot can cause a decrease in running or even walking ability and abnormal gait, such as outward gait.
4.Pain and abnormal gait may affect other joints in the body, such as compensatory valgus of the knee joint and compensatory external rotation of the hip joint due to excessive valgus and internal rotation of the affected foot, which may lead to pain and arthritis in the knee, hip, lower back and other parts. Individual patients with flatfoot may have lower back pain as the only symptom.
5.Severe flatfoot deformity Other joints of the foot and ankle may be seen to be involved, such as reduced flexibility or even stiffness of the subtalar and transverse tarsal joints.
6.Flat foot syndrome may be accompanied by metatarsal fasciitis, tarsal sinus syndrome, etc.