What is the foot?
The foot (Latin: pes) is a complex structure consisting of numerous bones, muscles and ligaments, which has become an important supporting organ with the development of upright gait. Anatomically, it is divided into three parts: the tarsus, the metatarsus and the digiti.
Tarsus
The two largest tarsal bones are the talus and the calcaneus, which is even larger. The other representatives are the navicular bone (Os naviculare), the three cuneiform bones (Ossa cuneiformia) and the cuboid bone (Os cuboideum). When the body is in an upright position, only the rear part of the calcaneus – the bony basis of the heel – is on the ground.
Midfoot
The five metatarsal bones (ossa metatarsalia) form the middle area, with the first being the shortest and also the strongest, since rolling occurs primarily over the big toe. The second metatarsal bone is the longest; from the third to the fifth, the length decreases continuously.
Toes
Transverse and longitudinal arch
A transverse and a longitudinal arch serve to stabilize the foot. The transverse arch is formed by ligaments and tendons, while the longitudinal arch is formed by ligaments in the sole of the foot and by muscles that contract under load, which means that the loaded foot is always slightly shorter than the unloaded foot.
What is the function of the foot?
The foot is the most important supporting organ of the human body. When walking, movement occurs only in the two ankle joints and in the toe joints. The other joints (in the area of the tarsus and metatarsus) are so strongly fixed by their ligamentous connections that a springy arch is formed which allows only slight displacement. From the age of 12 to 13, the foot has developed its final shape with a transverse and a longitudinal arch, with the longitudinal arch in particular serving to support load.
Normally, 40 percent of the body’s weight rests on the balls of the feet and the remaining 60 percent on the heels – if you wear no shoes or only flat shoes. If you wear high heels, on the other hand, you shift almost 80 percent of your body weight onto the balls of your feet. In the long run, this destroys the fat cushions on the balls of the feet. Not only joint pain occurs, but also structural changes that lead to a bunion.
Where is the foot located?
The foot is connected to the two lower leg bones, the tibia and fibula, through the ankle joint. Its current skeletal shape is the result of a reshaping process in which the gripping function has largely been lost and almost only the supporting function is still important.
What problems can the foot cause?
Common problems are caused by malpositions: In flat or fallen arches (pes planus), the longitudinal arch is flattened. Those affected often also have a bent foot (pes valgus): In this case, the heel bone is bent inward when viewed from behind.
Hallux valgus (bunion) is a deformity of the big toe and the most common deformity of the lower extremity. In this case, the big toe is permanently tilted towards the outside of the body (i.e. towards the other toes). It mainly affects women: High heels and shoes that are too tight in the front area promote the painful toe deformity.
Osteoarthritis, inflammation due to incorrect loading or overloading of the foot, bone fractures (fractures) are other common health problems. The same applies to gout. In this metabolic disease, the uric acid level in the blood is pathologically elevated. The excess uric acid crystallizes and is deposited in the body, especially at the metatarsophalangeal joint, but also in the knee, for example. This results in attacks of severe pain in the affected joints (gout attack), which can last from hours to days.
A fungal infection on the foot (tinea pedis) can be very unpleasant and persistent. It usually starts between the toes and can spread to the entire sole of the foot.
