How the human foot works: anatomy, “weak points”, possible diseases and their prevention. Anatomy of the skeletal structure of the human foot

There are a total of 26 bones in the foot + 2 sesamoids (minimum). For this reason, the foot is deservedly considered the most complex anatomical formation, and, along with the hand, has earned a separate orthopedic subspecialty.

The bones of the foot, ossa pedis, are divided into three sections: the tarsus, tarsus, which forms the posterior part of the skeleton of the foot, the metatarsus, its central part, and the toes, digiti, which represent the distal part.

Bones of the foot.

TARSAL BONES. The tarsal skeleton includes 7 bones. It is customary to distinguish two rows: proximal, consisting of two bones (talus and calcaneus), and distal, including four bones (three sphenoid and cuboid). Between these rows of bones is the scaphoid bone. The bones of the proximal row are located one above the other: below - the calcaneus, calcaneus, above - the talus, talus. Because of this location, the talus bone has a second name - supracalcaneal.

Talus, talus, has a head, neck and body. The head, caput tali, is directed forward, has a spherical articular surface for articulation with the scaphoid bone, facies articularis navicularis. A short narrowed part of the bone extends from the head - the neck, collum tali, connecting the head to the body. The part of the body protruding upward with three articular surfaces is called the trochlea, trochlea tali. Of these three articular surfaces, the upper one, facies superior, serves for articulation with the tibia. The two lateral surfaces are ankle, fades malleolaris medialis et lateralis. On the side of the latter there is a lateral process, processus lateralis tali. A rough posterior process, processus posterior tali, protrudes from behind the trochlea of ​​the talus. It is divided by the groove of the tendon of the long flexor of the big toe, sulcus tendinis and flexoris hallucis longi, into two tubercles. On the lower surface of the body there are two articular surfaces, separated by a wide groove, sulcus tali: the posterior one, facies articularis calcanea posterior, and the anterior one, facies articularis calcanea anterior.

Talus.

calcaneus, calcaneus, is the most massive of the bones of the foot. It is distinguished by a body, corpus calcanei, ending at the back with a calcaneal tubercle, tuber calcanei; on the medial side of the body there is a protrusion - the support of the talus, sustentaculum tali. On the upper surface of the body there are posterior and anterior articular surfaces corresponding to those on the talus, facies articularis talaris posterior et anterior, while the anterior one, like the talus, is divided into two parts, one of which (medial) extends to the sustentaculum tali. The anterior and posterior articular surfaces are separated by a wide, rough groove of the calcaneus, sulcus calcanei. This groove, together with the groove of the talus, forms a depression - the sinus of the tarsus, sinus tarsi, which opens on the body of the bone from the lateral side. The sustentaculum tali arises from the body of the calcaneus on the medial side. It supports the head of the talus. On its lower surface there is the already mentioned groove, sulcus tendinis i. flexoris hallucis longi, which is a continuation of the groove of the same name on the talus. On the lateral side of the calcaneus there is a small process - the fibular trochlea, trochlea peronealis. Under it runs a groove of the tendons of the peroneal muscles, sulcus tendinis tt. peronei. At the anterior end of the body there is another articular platform for articulation with the cuboid bone, facies articularis cuboidea.

Heel bone.

Scaphoid, os naviculare, so named because it is shaped like a boat, the concavity of which faces the head of the talus. The concavity is occupied by the articular surface for the talus. The convex side is directed towards the three sphenoid bones. This surface is divided by ridges into three unequal articular areas for the named bones. On the lateral side there is an articular surface for the cuboid bone. At the medial edge of the bone there is a tuberosity, tuberositas ossis navicularis, to which the tendon of the tibialis posterior muscle is attached.

Scaphoid.

Three sphenoid bones, ossa cuneiformia, are part of the distal row of the tarsus and lie, as indicated, anterior to the scaphoid bone. All three bones live up to their name in shape, but differ from each other in size and position.

Inner, median, outer sphenoid bones.

Os cuneiforme mediale is the largest of the three named bones, with the tip of the wedge facing the back of the foot, and the widened base facing the sole. It has three articular surfaces: the posterior (depressed) - for articulation with the scaphoid bone, the anterior (flat) - for articulation with the first metatarsal bone, and the lateral - for articulation with the sphenoid bone.

Os cuneiforme intermedium is the smallest of the three sphenoid bones in size, and the most consistent in shape with the wedge. Unlike the previous bone, its base faces the back of the foot, and its sharp edge faces the sole. It has articular platforms for the surrounding bones: behind - for the scaphoid, in front - for the second metatarsal, on the outer and inner sides - for the adjacent wedge-shaped.

Os cuneiforme laterale - compared to the previous ones, it is medium in size, has a regular wedge-shaped shape, the base faces the back of the foot, and the apex faces the sole. It has the following articular platforms: at the back - for os naviculare, at the front - for os metatarsale III, on the inside - for os cuneiforme intermedium and os metatarsale II, on the outside - for os cuboideum.

Inner, median, outer sphenoid and cuboid bones.

Cuboid, os cuboideum, is located along the lateral edge of the foot between the calcaneus at the back and the IV and V metatarsals at the front, so there are two articular platforms on its front surface, and one on the back. Inner surface It comes into contact with the lateral sphenoid and scaphoid bones, and therefore carries two articular surfaces for articulation with them. Moreover, the first of them (for the lateral sphenoid bone) is large in size, and the posterior one is small, sometimes absent. The lateral edge of the bone is free from articular surfaces. On the plantar side there is a tuberosity, tuberositas ossis cuboidei, anterior to which there is a groove for the passage of the tendon of the peroneus longus muscle, sulcus tendinis musculi peronei longi.

Metatarsal bones. The metatarsus, tarsus, consists of five short tubular bones having a body, corpus, head, caput, and base, basis. The metatarsal bones are similar in shape and structure, but differ in size: the first metatarsal bone (located on the side of the big toe) is the shortest and most massive, the second is the longest. The heads of the metatarsal bones are narrowed in comparison with the bones of the metacarpus, and are significantly compressed from the sides. The bodies are prismatic in shape, curved in the sagittal plane, with their convexity facing the rear. The bases of the metatarsal bones articulate with the bones of the distal tarsal row and are equipped with characteristic articular surfaces. The head of os metatarsale I on the plantar side is divided by a protrusion into two platforms for articulation with the sesamoid bones. At the base of this bone there is a concave surface for articulation with the os cuneiforme mediale. On the side of the sole, at the base there is a tuberosity, tuberositas ossis metatarsalis I. The bases of os metatarsale II and III resemble a wedge, with the tip facing down. The base of os metatarsale IV is close in shape to a cube. At the base of os metatarsale V, on the lateral side there is a tuberosity, tuberositas ossis metatarsalis V, to which the tendon of the peroneus brevis muscle is attached.

1st, 2nd, 3rd, 4th, 5th metatarsal bones.

The bones of the metatarsus and tarsus do not lie in the same plane, but form longitudinal arches, convexly facing upward. As a result, the foot rests on the ground only on some points of its lower surface: at the back, the fulcrum is the calcaneal tubercle, at the front - the heads of the metatarsal bones. The phalanges of the fingers only touch the support area. According to the bones of the metatarsus, five longitudinal arches of the foot are distinguished. Of these, the I-III arches do not touch the plane of support when the foot is loaded, so they are spring-type; IV and V - adjacent to the support area, they are called supporting. Due to the different shape and convexity of the longitudinal arches, the lateral edge of the foot (IV-V arches) descends towards the support area, the medial edge (I-III arches) has a clearly defined arched shape.

In addition to the longitudinal arches, there are two transverse arches (tarsal and metatarsal), located in the frontal plane, convexly facing upward. The tarsal arch is located in the area of ​​the tarsal bones; metatarsal - in the area of ​​the heads of the metatarsal bones. Moreover, in the metatarsal arch, the planes of support touch only the heads of the first and fifth metatarsal bones.

The arches of the foot provide a shock-absorbing function during static loads and walking, and also prevent compression of soft tissues during movement and create favorable conditions for normal blood circulation.

PHALANXES OF THE TOES. The skeleton of the toes is similar to the skeleton of the fingers of the hand, i.e. it consists of phalanges, phalanges digitorum pedis, the number, shape and names of which are the same as on the hand (the first toe, hallux, also has only two phalanges). The phalanges of the first finger are thicker; the remaining fingers are much smaller, especially the short phalanges of the fourth and fifth fingers. In the little finger, the middle and distal (ungual) phalanges often grow together. The body of the proximal phalanges is much thinner compared to the middle and distal ones, and is close to a cylinder in shape.

The foot, like the hand, has sesamoid bones. They are located constantly in the area of ​​the metatarsophalangeal joints of the big toe and little finger, and in the interphalangeal joint of the big toe. In addition to the mentioned sesamoid bones, there are also unstable bones in the tendons of m. peroneus longus et m. tibialis posterior.

CONNECTIONS OF THE BONES OF THE FOOT

All connections of the bones of the foot, articulationes ossa pedis, can be divided into four groups:

1) the articulation between the bones of the foot and lower leg - articulatio talocruralis;

2) articulations between the bones of the tarsus - articulationes subtalaris, talocalcaneonavicularis, calcaneocuboidea, cuneonavicularis, intertarseae;

3) articulations between the bones of the tarsus and metatarsus - articulationes tarsometatarseae;

4) articulations between the bones of the fingers - articulationes metatarsophalangeae and interphalangeae.

ANKLE JOINT. The ankle joint, articulatio talocruralis (supragal joint), is formed by both bones of the lower leg and the talus. Its articular surfaces are: the articular fossa, which looks like a fork, formed by fades articularis inferior tibiae, fades articularis malleoli medialis (on tibia), fades articularis malleoli lateralis (on the fibula). Articular head is represented by the block of the talus with its articular surfaces: facies superior, facies malleolaris medialis and facies malleolaris lateralis.

The joint capsule is attached along the edge of the articular cartilage and only deviates from it in front (on the tibia about 0.5 cm, on the talus - almost 1 cm). It is free in front and back. The capsule is stretched on the sides and supported by strong ligaments. The ligaments that strengthen the joint are located on its lateral surfaces.

The medial (deltoid) ligament, ligamentum mediale, includes four parts: the tibiobionavicular part, pars tibionavicular, the anterior and posterior tibiotalar parts, partes tibiotalares anterior et posterior, and the tibiocalcaneal part, pars tibiocalcanea.

On the lateral side, the joint capsule is strengthened by three ligaments. The anterior talofibular ligament, ligamentum talofibulare anterius, runs almost horizontally from the anterior edge of the malleolus lateralis to the anterior edge of the lateral platform of the talus. The calcaneofibular ligament, ligamentum calcaneofibulare, starts from the outer surface of the malleolus lateralis, goes down and back to the lateral side of the calcaneus. The posterior talofibular ligament, ligamentum talofibulare posterius, connects the posterior edge of the malleolus lateralis with the posterior process of the talus.

The shape of the ankle joint is typical block-shaped. It allows movements around the frontal axis: plantar flexion; extension (dorsiflexion). Due to the fact that the trochlea of ​​the talus is narrower at the back, lateral rocking movements are possible with maximum plantar flexion. Movements in the ankle joint are combined with movements in the subtalar and talocaleonavicular joints.

CONNECTIONS OF THE TARSAL BONES. The articulations of the tarsal bones are represented by the following joints: subtalar, talocaleonavicular, calcaneocuboid, wedge-navicular.

The subtalar joint, articulatio subtalaris, is formed by the articulation of the posterior calcaneal articular surface, facies articularis calcanea posterior, on the talus bone and the posterior talar articular surface, facies articularis talaris posterior, on the calcaneus. The joint is cylindrical; movements in it are possible only around the sagittal axis.

The talocalcaneonavicular joint, articulatio talocalcaneonaviculars, has a spherical shape. It contains the articular head and the cavity. The articular head is represented by the scaphoid articular surface, fades articularis navicularis, and the anterior calcaneal articular surface, fades articularis calcanea anterior, which are located on the talus. The glenoid cavity is formed by the posterior articular surface, facies articularis posterior, of the scaphoid bone and the anterior talar articular surface, facies articularis talaris anterior, of the calcaneus. The articular capsule is attached to the edges of the articular surfaces.

Subtalar, talocaleonavicular, calcaneocuboid, wedge-navicular, tarsometatarsal joints.

The plantar calcaneonavicular ligament, ligamentum calcaneonaviculare plantare, strengthens the joint capsule from below. In the place where the ligament comes into contact with the head of the talus, in its thickness there is a layer of fibrous cartilage, which participates in the formation of the glenoid cavity. When it stretches, the head of the talus descends and the foot flattens. On the dorsal surface, the joint is strengthened by the talonavicular ligament, ligamentum talonavicular. This ligament connects the dorsum of the neck of the talus and the scaphoid. On the sides, the joint is strengthened by the lateral talocalcaneal ligament, ligamentum talocalcaneum laterale, and the medial talocalcaneal ligament, ligamentum talocalcaneum mediale. The lateral talocalcaneal ligament is located at the entrance to the sinus tarsi in the form of a wide band, has an oblique fiber direction and runs from the lower and outer surfaces of the neck of the talus to the upper surface of the calcaneus. The medial talocalcaneal ligament is narrow, directed from the tuberculum posterius tali to the posterior edge of the sustentaculum tali of the calcaneus. The sinus of the tarsus, sinus tarsi, is filled with a very strong interosseous talocalcaneal ligament, ligamentum talocalcaneum interosseum.

Despite the fact that the talocalcaneal-navicular joint is spherical in shape of the articular surfaces, movement in it occurs only around an axis that passes through the medial part of the head of the talus to the lateral surface of the calcaneus (slightly below and posterior to the place of attachment of the ligamentum calcaneofibulare). This axis simultaneously serves as an axis for the articulatio subtalaris. Consequently, both joints function as a combined talotarsal joint, articulatio talotarsalis. In this case, the talus remains motionless, and together with the heel and navicular bones the entire foot moves.

When the foot rotates outward, the medial edge of the foot rises (supinatio) and at the same time it is adducted (adductio). When the foot rotates inward (pronatio), the medial edge of the foot lowers and the lateral edge rises. In this case, the foot is abducted.

Thus, when moving the foot, extension (extensio, or flexio dorsalis) is combined with supination and adduction (supinatio, adductio); flexion of the foot (flexio plantaris) can be combined with both pronation and abduction (pronatio, abductio) and supination and adduction (supinatio, adductio). In a child (especially the first year of life), the foot is in a supinated position, so when walking the child places the foot on its lateral edge.

The ankle joint (supratal joint), subtalar and talocaleonavicular joints (articulatio talotarsalis) can function independently. In the first, flexion and extension predominate, in the other two, supination and pronation. But this rarely happens; usually they function together, forming, as it were, one joint - the joint of the foot, articulatio pedis, in which the talus plays the role of a bone disc.

The calcaneocuboid joint, articulatio calcaneocuboidea, is formed by the articular surfaces: facies articularis cuboidea calcanei and fades articularis posterior ossis cuboidei.

The articular surfaces are saddle-shaped. The articular capsule on the medial side is thick, strong and tightly stretched, on the lateral side it is thin and loose. The capsule is strengthened by ligaments, which are especially developed on the plantar side. The strongest of them is the long plantar ligament, ligamentum plantare longum. This ligament starts from the lower roughness of the calcaneus and consists of several layers. Its deep bundles are attached to tuberositas ossis cuboidei; the superficial bundles are the longest, spread over the sulcus tendineus t. peronei longi (turning the groove into a canal in which the t. peroneus longus is located) and are attached to the bases of the ossa metatarsalia II-V.

Deeper than the long plantar ligament is the plantar calcaneo-cuboid ligament, ligamentum calcaneocuboideum plantare, consisting of short fibers that lie directly on the joint capsule and connect areas of the plantar surfaces of the calcaneus and cuboid bones.

The calcaneocuboid joint is saddle-shaped in shape, but functions as a uniaxial rotational joint, combining with the talocaleonavicular and subtalar joints.

From a surgical point of view, articulatio calcaneocuboidea and articulatio talonavicularis (part of articulatio talocalcaneonaviculars) are considered as one joint - the transverse joint of the tarsus articulatio tarsi transversa (Shopard joint). The articular surfaces of these joints have a weakly expressed S-shaped shape, that is, they are located almost on the same transversely oriented line. Along this line you can isolate the foot. In this case, it is necessary to cut a special bifurcated ligament, ligamentum bifurcatum (Shopard's key of the joint), which holds the calcaneus, navicular and cuboid bones relative to each other. The ligamentum bifurcatum (bifurcated ligament) begins on the upper edge of the calcaneus and is divided into two ligaments: the calcaneonavicular, ligamentum calcaneonaviculare, and the calcaneocuboid, ligamentum calcaneocuboideum. The calcaneonavicular ligament is attached to the posterolateral edge of the os naviculare, and the calcaneocuboid ligament is attached to the dorsal surface of the cuboid bone.

The cuneonavicular joint, articulatio cuneonavicularis, is formed by the facies articularis anterior ossis navicularis and the posterior articular surfaces ossa cuneiformia I-III, as well as the lateral articular platforms of the sphenoid, cuboid and scaphoid bones facing each other. The joint cavity has the appearance of a frontal gap, from which one process extends backward (between the scaphoid and cuboid bones), and three - forward (between the three sphenoid bones and the cuboid). The joint is flat, the joint capsule is attached to the edges of the articular surfaces. The joint cavity constantly communicates with the articulatio tarsometatarsea II through the gap between the ossa cuneiformia mediale et intermedium. The joint is strengthened by the dorsal and plantar cuneonavicular ligaments, ligamenta cuneonavicularia plantaria et dorsalia, interosseous intercuneiformia ligaments, ligamenta intercuneiformia interossea, dorsal and plantar intercuneiformia ligaments, ligamenta intercuneiformia dorsalia etplantaria. Interosseous ligaments can only be seen on a horizontal cut of the foot or on an opened joint when the articulating bones are pulled apart. The joint is typically flat, with little movement between the bones.

TARIMATASAL JOINTS. The connections between the tarsus and metatarsal bones (articulationes tarsometatarseae) are flat joints (only in joint I metatarsal there are weakly expressed saddle-shaped surfaces). There are three of these joints: the first - between os cuneiforme mediale and os metatarsale I; the second - between ossa cuneiformia intermedium et laterale and ossa metatarsalia II et III (the cavity of this joint communicates with the articulatio cuneonavicularis); the third is between os cuboideum and ossa metatarsalia IV et V.

All three joints are surgically combined into one joint, the Lisfranc joint, which is also used to articulate the distal part of the foot. The joint capsules are strengthened by the dorsal and plantar tarsometatarsal ligaments, ligamenta tarsometatarsea dorsalia et plantaria.

Between the sphenoid and metatarsal bones there are also three interosseous sphenoid-metatarsal ligaments, ligamenta cuneometatarsea interossea. The medial interosseous cuneiform-metatarsal ligament, which is stretched between the medial cuneiform bone and the second metatarsal bone, is the key to the Lisfranc joint. The tarsometatarsal joints are flat in shape and inactive.

Intermetatarsal joints, articulationes intermetatarsae, are formed by the surfaces of the metatarsal bones facing each other. Their capsules are strengthened by the dorsal and plantar metatarsal ligaments, ligamenta metatarsea dorsalia et plantaria. There are also interosseous metatarsal ligaments, ligamenta metatarsea interossea.

On the foot, as on the hand, a solid base can be distinguished, i.e., a complex of bones that are connected to each other almost motionlessly (movements here are minimal). The hard base of the foot includes a larger number of bones (10): os naviculare; ossa cuneiformia mediale, intermedium, laterale; os cubeideum; ossa metatarsalia I, II, III, IV, V, which is associated with the difference in the functions of the foot and hand.

The metatarsophalangeal joints, articulationes metatarsophalangeae, are formed by the heads of the metatarsal bones and the fossae of the bases of the proximal phalanges. The articular surfaces of the heads of ossa metatarsalia II-V have an irregular spherical shape: the plantar part of the articular surface is significantly flattened. The articular fossae of the phalanges are oval in shape. The joint capsule is free, attached to the edge of the articular cartilage; With back side she is very thin. On the lateral and medial sides, the joints are secured by collateral ligaments, ligamenta collateralia. On the plantar side, the joints are strengthened by plantar ligaments, ligamenta plantaria (these ligaments sometimes contain fibrous cartilage and sesamoid bones). There is also a deep transverse metatarsal ligament, ligamentum metatarseum transversum profundum. It is a fibrous cord that is located transversely between the heads of the I-V metatarsal bones and fuses with the capsules of the metatarsophalangeal joints, connecting the heads of all metatarsal bones. This ligament plays an important role in the formation of the transverse metatarsal arch of the foot.

Articulatio metatarsophalangea I is distinguished by some features: the plantar part of the capsule of this joint is constantly enclosed by two sesamoid bones, to which two grooves correspond on the articular surface of the head of os metatarsale I. Therefore, the metatarsophalangeal joint of the big toe functions as a trochlear joint. It performs flexion and extension around the frontal axis. The joints of the remaining four fingers function as ellipsoidal joints. They allow flexion and extension around the frontal axis, abduction and adduction around the sagittal axis, and, to a small extent, circular movement.

CONNECTIONS OF FINGER BONES. The interphalangeal joints, articulationes interphalangeae, are similar in shape and function to the same joints of the hand. They belong to the block joints. They are strengthened collateral ligaments, ligamenta collateralia, and plantar ligaments, ligamenta plantaria. In the normal state, the proximal phalanges are in a state of dorsiflexion, and the middle ones are in plantar flexion.

Human feet are a part of the body through which a person moves, maintains balance, and with the help of the foot the body can provide resistance while performing many movements. The process of evolution has made the structure of the foot complex, due to which modern man can walk upright.

The foot consists of 26 bones that are connected by ligaments and joints. There are also many muscles and tendons there. In anatomy, there are three sections of the foot, which will be discussed below.

Foot bones

As you know, the human foot resembles the hands; there are sections that are similar in structure, but they are called differently.

The feet have:

1. Tarsal bones. This part of the foot consists of seven bones - the calcaneus and talus are large, the rest are wedge-shaped, club-shaped and navicular. The talus is located in the area between the bones of the lower leg and is part of the ankle.
2. Metatarsus - middle part of the foot. Consists of five tube-shaped bones, they go to the beginning of the fingers. At the end of these bones there is a joint surface that helps the fingers move. Also, this group of bones ensures the correct level of the arch.
3. The end of the foot is the phalanges of the fingers (rib formation); they are mobile due to the presence of joints between them. There are 14 bones in this part. The thumb consists of two bones, and the rest have 3 in each finger. Due to this part, a person can maintain body balance and perform simple movements. However, there have been many cases where, as a result of the loss of arms, a person maintains his vital functions with the help of his toes.

The bones are connected to each other by joints. The correct structure of the ankle and foot bones is ensured by nerves, blood vessels, ligaments, muscles and joints.

Location of bones

As you know, bones are an important element responsible for structure. They need to be considered in more detail.

The largest bone is the calcaneus, located in the back of the foot and bears a lot of load, this bone partly contributes to the flexibility of both arches. The bone is not part of the ankle, but it distributes pressure. It is shaped like a three-dimensional rectangle with a long axis.

In the front part there are joints that are needed for the strongest connection between the heel and heel, thereby ensuring the normal shape of the foot. There is a small protrusion at the back of the bone where the Achilles tendon is attached. The bottom side of the person steps on the ground.

There is also a tubercle in the front for connection to the joint. The entire surface is covered with protrusions and depressions for the attachment of nerves, blood vessels, muscles and ligaments.

Slightly smaller is the talus, which enters the ankle. Almost all of it is covered with cartilage, and what is most interesting is that nothing except ligaments is attached to it. The bone has five surfaces covered with a thin layer of hyaline cartilage.

It consists of a body, head and neck:

• body - is part of the ankle, connected to the foot through ligaments and joints;
• The head is the front of the bone that has an articular surface. The head provides a strong connection to the boat.
• The neck is the thin part located between the head and the body.

Cuboid. Located on the outside of the foot behind the fourth and fifth metatarsal bones. Outwardly, it looks like a cube, which gave it its name.

Scaphoid. Its peculiarity is that it is located on the foot itself and, through joints, is brought together with the talus bone, forming.

Sphenoid bones. There are three such bones on the human foot; they are small in size and located close to each other (in rib order). Behind them is the navicular bone, and in front of them are the metatarsal bones.

The structure and functions of the metatarsal bones are the same in both adults and childhood. Anatomical appearance - tube-shaped with an angled bend. This bend forms the arches of the feet. There are tubercles on the surface for attaching ligaments, muscles and joints.

The bones of the phalanges of the fingers are identical to those on the hands, differing only in size. The big toe has two phalanges, the other four toes have three.

Due to the load on the feet, the phalanges of the big toe are thick, while the rest are thin and short. They are connected to each other by joints, thanks to which a person can bend and straighten his fingers.

Structure of joints

The feet have many joints that move several bones together at the same time. Regarding size, the ankle joint is considered the largest; it connects three large bones together. Thanks to this connection, a person can raise and lower the foot, as well as rotate it. All other joints are smaller, but perform the same function, which together makes the foot flexible and mobile.

The ankle joint consists of a large talus and two smaller tibia bones. The latter have ankles that fix the talus. There are strong ligaments along the edges, and the joint itself is attached to the cartilage that covers the surface of the bone.

An important component is the subtalar (transverse) joint, which consists of a low-moving joint and performs the function of the arch of the talus and calcaneus. It connects three bones - the scaphoid, calcaneus and talus; ligaments are also involved in the connection process, contributing to a tighter fixation.

The cuboid and calcaneus bones are connected by the joint of the same name. Together with the subtalar, they form a practical type of education. This connection is sometimes called the "Greek cavity" and is known medically as "".

As for surgical practice, the joints that are located on the scaphoid and sphenoid bones are of least importance. But the metatarsals are connected by low-moving joints; they are surrounded by elastic ligaments and are part of the transverse and longitudinal arches of the foot. The intermetatarsal joints are located costally in the space between the metatarsal bones.

One of the most important joints are those called metatarsophalangeal joints; they are involved in almost every step or movement of the body when walking.

Foot ligaments

The most important of all is the longitudinal (or long) plantar ligament. The ligament extends from the heel bone and reaches the beginning of the metatarsal bones. It has many branches that perform the function of strengthening and fixing the longitudinal and transverse arches, and also maintains them in normal condition throughout life. But, as you know, violation of the arches of the feet can indicate flat feet, the treatment of which sometimes takes more than one year, especially if it concerns an adult.

The remaining, smaller ligaments also fix and strengthen the bones and joints of the foot, which helps a person maintain body balance and withstand dynamic and static loads during long walking or running.

Any movements of the feet are possible only with the help of the muscles that are located in the area of ​​the foot, ankle and lower leg. The important thing is that the calf muscles help make many movements of the feet, both when walking and in an upright position.

Calf muscles

In the anterior part there is a group of long extensor muscles, the tibialis muscle. A person uses them when performing dorsal extension or flexion of the feet. Thanks to these muscles, a person can straighten and bend his fingers.

The external or lateral group includes the short and long peroneus muscles. With their help, it is possible to perform pronation, as well as lateral flexion of the foot.

The back part is distinguished by massive muscle groups consisting of many layers. They have a huge daily workload. This includes the triceps muscle, which consists of the gastrocnemius and soleus muscles. This area contains the flexor digitorum longus muscle, as well as part of the tibialis muscle. These muscle groups allow plantar flexion to be performed using the Achilles tendon. They are also involved in the process of extension and flexion of the fingers.

The dorsal muscle group contains the extensor digitorum brevis. It originates from the heel and is responsible for the motor activity of the four toes, but does not control the big toe.

On the sole of the foot there are several small muscles responsible for adduction, abduction and flexion of the toes.

Vessels and nerves

The posterior and anterior tibial arteries are responsible for the flow of blood into the human feet. On the foot itself, these arteries continue with the external internal and dorsal arteries located on the plantar part. They also form a small number of arterial connections and circles. And in case of injury of varying severity, when damage occurs to one of the circles, the rest will be able to ensure normal blood flow to the feet.

As for the outflow of blood, it is carried out by the veins of the same name, which are located on the back side. These veins form the weave. Thanks to them, blood flows into the small and large saphenous veins located in the lower leg.

Nerve impulses from the central nervous system are transmitted along the sural, deep peroneal, superficial and posterior tibial nerves. Thanks to nervous innervation, a person feels movement in space, vibration, pain, touch, and distinguishes between cold and heat. All nerve impulses are processed in the spinal cord.

These same nerves provide signal transmission from the brain to muscle groups. Such impulses are called reflexes, which can be involuntary or voluntary. As for the latter, this is observed when muscle tissue contracts, which does not always depend on the will of the person. The reason for this phenomenon may be the work of sweat and sebaceous glands, increase or decrease in the tone of the vascular walls.

The top layer is skin covering. The skin on the feet differs depending on the area of ​​the foot. On the sole itself it has a high density, but in the heel area it is thicker. The skin has the same structure as on the palms, but as a result of high loads, it begins to layer with age. In the dorsal area, the skin is quite smooth and elastic, there are nerve endings here.

So, based on everything that has been said above, it becomes clear that nature has made sure that the feet can withstand enormous pressure. The formation of the foot is rarely influenced by a person's nationality or the conditions in which he lives.

If at least one element of the foot is injured, a hyperkeratotic form of mycosis of the feet, deforming osteoarthritis, flat feet, heel spurs and other serious diseases may develop.

Possessing complex structure, the bones of the foot together provide important functions. Among the main tasks are adaptation to the surface, ensuring movement, and a soft and elastic gait. Pathology or injury to any of the elements of this system will have a detrimental effect on the remaining components of this part of the limb.

Functions and structure

The human foot is a complex structure necessary to maintain an upright body position, absorb the force of contact with the ground when walking (about 70%), and move on a wide variety of surfaces. This organ consists of 26 bones, differing in structure and appearance, connected to each other by muscles and ligaments.

A person can be born with extra bones, which usually do not cause direct or indirect harm to the person.

Compound bone structures among themselves - the function of the joints, ensuring the integrity and mobility of the skeleton, the coordination of the movement of individual elements and the ability to perform complex gestures. A joint is a connection of bones that is capable of moving its parts relative to each other while remaining intact. The surfaces involved in the formation of the connection are covered with cartilaginous tissue of extremely low roughness. The space between the bones is filled with lubricating joint fluid, which facilitates gliding. All elements are enclosed in a joint capsule, which protects the system from violation of the integrity and damage to its components.

Leg joints are often injured. A fall or poor positioning of the leg can lead to a dislocation or fracture. To avoid complications, you should entrust the treatment of such injuries to a qualified specialist. The structure of the bones of the foot is described in detail below.

The foot is divided into three functional parts:

• Distal - toes, consisting of small movable elements.
• The metatarsus is the middle fragment, which is made up of long bones similar to each other.
• The tarsus is a complex supporting section.

The fingers are made up of phalanges - short tubular bones. Similar to the structure of the upper limbs, the big toes contain 2 phalanges, and the rest have 3. The base of the toe is made up of: proximal, middle and distal (ungual) bones. Often the little toes contain 2 phalanges due to the fusion of the nail and middle. The bones of the fingers have a cylindrical body, crowned at one end by the proximal epiphysis (base) and on the other by the distal epiphysis (head). The latter has a tubercle. The heads of the proximal and middle phalanges are block-shaped.

The base of the proximal phalanx has a depression to form the metatarsophalangeal joint with the corresponding metatarsal bone. The role of these joints is to partially ensure flexion and extension of the fingers, as well as some abduction and adduction. The phalanges of each individual finger are connected by trochlear interphalangeal joints, allowing the fingers to flex and extend.

The metatarsophalangeal joints experience significant stress, which increases the risk of diseases.

The metatarsal bones (long, tubular, 5 in number) form a transverse arch, softening cyclic shock loads when walking, jumping and running. The first metatarsal bone of the foot (counting from the first toe) is the widest and shortest, the second is longer than all the others. The shape of all metatarsal bones is similar: the triangular body ends at one end with a relatively massive base (proximal epiphysis), at the other end with a head flattened on the sides (distal). The metatarsal bones are well palpated from the back of the foot, covered with a relatively small layer of soft tissue. The body of the bones bends slightly upward. From below, the base has a palpable tuberosity.

The heads of the bones have sphere-like articular surfaces that contact the proximal phalanges of the fingers. The lateral articular platforms on the bases enter the intermetatarsal joints, the posterior ones form articulations with the tarsal bones.

The first and fifth metatarsophalangeal joints contain sesamoid bones - small additional round or disc-shaped formations. Sesamoid bones can also be found at the interphalangeal joint of the first finger, on the inferior side of the cuboid bone.

The first metatarsophalangeal joint is often subject to arthrosis. The distortion of its shape is due to the formation of a bone growth on the outer edge of the metatarsus bone

The bones of the foot in this area have different shapes, their anatomy is quite complex. The tarsus has 2 rows - distal and proximal. The size of the tarsal bones of the human foot is associated with heavy loads due to upright walking. The only one directly connected to the lower leg is the talus bone of the foot; the remaining fragments of this section increase the arch of the foot. Each of the components of the foot skeleton is discussed in more detail below.

The lateral section of the distal row contains 5 bones.

• The cuboid bone found its place at the outer (lateral) edge of the foot in the space limited partly by the calcaneus and lateral cuneiform, and partly by the metatarsals. The groove marked underneath the bone is made for the muscle tendon. In front, the bone has a surface for the IV and V metatarsal bone formations, divided by a ridge. At the back it contacts the calcaneus, for which there is a saddle-shaped surface and a calcaneal process. The articular platforms on the medial side are intended for the adjacent tarsal bones.
• The navicular bone of the foot is located at its inner edge. The ends of the formation are flattened, the upper surface is arched, and the lower surface is sunken. On the lateral edge there is a small area in contact with the cuboid bone. The oval depression of the posterior part of the scaphoid bone with the corresponding convexity of the talus creates the joint of the same name. The anterior surface bears articular facets for the three sphenoid bones, and between them lie ridge-like processes. The listed fragments form a sedentary sphenoid joint.
• Wedge-shaped formations owe their name to their appearance. In the direction from the outer rib there are: medial (largest), intermediate (smaller) and lateral (average of three in size) bones. Their dorsal parts are attached to the scaphoid bone. The cuneiform, cuboid, and metatarsal joints form the tarsometatarsal joints. This system, due to many ligaments, is quite rigid and forms a solid base of the foot.

The proximal row includes fairly large structures: the talus and calcaneus. Their sponginess makes them resistant to heavy loads.

• The talus is a massive body facing the heel, flows into a more refined part - the neck, ending in an oval head, “looking” towards the fingers. The formation on the upper body is called a block. The upper articular platform of the block is of complex shape, connected to the lower part of the tibia. The lateral (outward-facing) and medial (inner) sides of the block are attached to the ankles. This formation is a component of the ankle, the role of which is to ensure flexion and extension of the leg. This is a powerful connection, but due to the loads it perceives, it often gets injured or becomes ill, which significantly complicates life with severe pain when moving. The tip of the head of the talus, which has a spherical articular formation, is in contact with the scaphoid bone. Two, located below and separated by a transverse groove, are intended for docking with the heel bone. The talus and calcaneus at the point of connection with each other form the subtalar joint - cylindrical, with an axis of rotation in the sagittal plane. Dysfunction of this connection increases the risk of leg injury due to forced redistribution of loads.
• The calcaneus is located in the posterior tarsus on the plantar side. Continuing the vertical axis human body, carries almost all of its mass. This is the largest, strongest and heaviest bone in the foot. It is oblong, flattened on the sides, the main parts are the body and the tubercle (thickening at the rear end), which are easy to palpate. The anterior protruding fragment of the medial part of the bone provides support for the talus. A long recess on the lateral side is provided for the muscles of the tendon. At the back, the talus bone and the heel protrusion are also cut from top to bottom by a groove; inside it is placed the flexor tendon of the first finger. The lower parts of the tubercle protrude, forming 2 processes - lateral and medial. Below on the tubercle is the calcaneal tubercle.

The occurrence of a “heel spur” can cause gait disturbances due to unpleasant sensations.

The saddle-shaped surface for the cuboid is on the side of the heel closest to the toes, they form the calcaneocuboid joint. The calcaneus is part of the ball-shaped talocaleonavicular joint, strengthened by powerful ligaments. Coupling with the subtalar, it rotates the foot outward and back.

Thanks to these joints, it becomes possible to perform complex leg movements - dance, acrobatic, etc.

From the above it follows that the bones of the human foot have different structures, depending on the tasks assigned to them.

Muscles

The poorly developed muscles of the upper side of the foot perform only extension of the toes, while the plantar muscles perform shock-absorbing functions.

The condition of the muscles affects the functions of the limb: excessive tension or poor development will inevitably affect the joints. The opposite statement is also true: diseases of the skeleton will affect the muscles. Excessive relaxation of the muscles of the foot and lower leg can lead to flat feet.

Tendons and ligaments

Bones are attached to muscles through tendons - elastic tissues that take on excess load when the muscles are stretched. A tendon that is stretched too far can become inflamed.

Ligaments surround the joint, maintaining its integrity. This fabric is quite flexible, but not elastic. A rupture or sprain of a ligament can cause swelling of the injured limb, severe pain and hemorrhage, and limited mobility. Due to ignorance, symptoms can be confused with signs of other types of injuries.

Lack or complete absence of blood supply to the bones leads to osteonecrosis - destruction of bone substance due to the death of “starving” cells. The consequence may be degenerative arthritis.

The large arteries of the leg are the dorsal and posterior tibial. Veins – large (on the inside of the leg), small (on the outside), as well as deep-lying tibial veins. Arteries fill tissues with blood, and veins drain it. Smaller vessels provide blood circulation in individual areas, capillaries connect them to each other. Impaired blood flow leads to tissue depletion of oxygen. The distance from the heart is the reason that the feet are the first to feel the consequences.

Blood supply problems are diagnosed by changes in skin tone, cooling, and the presence of edema. Symptoms often worsen in the late afternoon or after heavy exercise. Varicose veins are also a common disease.

Cartilage

The substance of cartilage smoothes the articular surfaces, providing smooth movements and preventing inflammation that is inevitable due to friction.

Diseases

The foot undergoes regular loads: static when standing or shock during movement. It's no wonder that her injuries and pathological changes so not uncommon. In addition to inevitable pain, a symptom of the disease can also be a visible violation of the norm - enlargement of individual epiphyses, swelling, curvature of the fingers. The deformation is especially evident with X-rays. The most common pathologies are discussed below.

The cause of arthrosis is the loss of elasticity of cartilage, which occurs when metabolic processes in the joint are disrupted. Symptoms of the disease: pain when working the joint, a characteristic crunch, swelling around the affected area, disruption of the anatomy of the fingers.

Among the causes of arthrosis are the following:

• systemic connective tissue diseases: lupus erythematosus, scleroderma, etc.;
• infectious diseases;
• allergic reactions;
• consequences of dislocations, synovitis (fluid accumulations in the joint cavity), bruises;
• metabolic disorders;
• tuberculosis, syphilis.

One of the characteristic types of the disease is arthrosis of the first toe. Its development goes through 3 stages.

• At the end of or after prolonged exercise, pain occurs, which fades after a long rest. There may be some deviation in the shape of the thumb, which is still minor. When moving, you can hear a crunching sound.
• To eliminate increasing pain, take painkillers and anti-inflammatory drugs. The big toe is severely curved, which makes choosing shoes difficult.
• The pain does not disappear even after using analgesics. The deformity affects the entire foot, impairing its supporting ability.

Another “favorite” place for arthrosis is the ankle. On late stages The cartilage tissue is affected and the joint is deformed.

It is possible to slow down the development of arthrosis without resorting to surgical intervention only in the early stages. Establish control over potential reasons diseases, optionally prescribe physiotherapeutic measures. Advanced disease is treated surgically: endoprosthetics or more gentle methods - resection of formations, arthroplasty.

Arthrosis, which affects exclusively the joints, resembles another disease with a similar name - arthritis, due to which the body as a whole suffers, and joint diseases are complicating.

Arthritis

Depending on whether the joint is damaged or its pain is caused by other reasons, primary and secondary arthritis are distinguished. The pathology is caused by the same reasons as arthrosis.

Main symptoms of arthritis:

• pain;
• the affected area or the lower part of the limb swells, the skin turns red;
• limb deformity;
• in some cases, an increase in temperature is observed, a rash forms, and fatigue overcomes.

Treatment of arthritis is based on eliminating the root cause of the disease, which requires accurate diagnosis and control of specialists. For example, treatment methods systemic diseases joints and connective tissue may require a different approach: medication (drugs like Depos), physiotherapeutic, manual, etc.

There are intermediate conditions between arthrosis and arthritis, bearing symptoms of both, characterized by pain, predominantly aching in nature.

Foot deformities

Pathological changes can be acquired or congenital. The most common distal leg deformities are described below.

The flattening of the foot leads to a weakening of its spring function. The disease may be congenital or develop over time. The causes of acquired flat feet include the following:

• excess load, excess weight;
• diseases of nerve endings;
• past or active diseases: rickets, osteoporosis;
• injuries;
• poor quality shoes.

There are two types of flat feet.

• Transverse is characterized by a decrease in the height of the corresponding arch. All metatarsal heads are in contact with the floor, when only I and V should be.
• With longitudinal flatfoot, the entire sole is in contact with the surface. In addition to increased fatigue and pain in the lower extremities, human organs suffer from excessive shock loads.

Clubfoot

In most cases, pathology accompanies a person from birth. Subluxation of the ankle joint leads to a pronounced supinator position of the foot. Its length is shortened. The causes of deviations acquired during life can be injuries to the lower extremities, paralysis, and paresis. Clubfoot, which is congenital, is diagnosed upon examination.

Disease Prevention

The development of pathologies can be partially or completely prevented by taking into account the following recommendations.

• Warm-up exercises will prepare the limbs for the upcoming load.
• Participating in gentle sports (skiing, cycling, swimming) will help keep the complex system of leg muscles in good shape, which in itself is a good prevention of diseases.
• Walking on pebbles, sand, and grass has a beneficial effect on the soles of your feet.
• Giving up uncomfortable shoes will benefit your limbs and overall well-being.
• Reducing the frequency of wearing high heels will reduce the risk of complications.
• Wearing appropriate footwear for sports will reduce the impact on all body systems. These shoes should be changed periodically.
• Feet need regular rest, just like the rest of the body.

Some threats to well-being are not obvious, including the dependence of the health of internal organs on the choice of sneakers for a morning run. Some cases require a mandatory visit to the doctor, but to preserve your own health, sometimes it is enough to avoid obviously harmful situations.

Since a person moves in an upright position, the lion's share of the load falls on the lower extremities. Therefore, it is important to monitor your body weight, making it easier for the bones of the foot to work.

The structure of the ankle joint in humans is represented by the articulation of the bones of the foot with the shin bones, ensuring the performance of complex functions.

Human ankle joint

The bones are clearly shown in the diagram and classified into groups.

These include:

1. Articulation of the bones of the lower leg with the bones of the foot.
2. Internal articulation of the tarsal bones.
3. Articulations between the bones of the metatarsus and tarsus.
4. Articulations of the proximal phalanges with the metatarsal bones.
5. Articulation of the phalanges of the fingers with each other.

The anatomical abilities of the foot suggest high level motor activity. For this reason, a person can perform heavy physical activity.

Both the foot and the entire leg are designed to help a person move freely in the environment.

The structure of the foot is divided into 3 working parts:

1. Bones.
2. Ligaments.
3. Muscles.

The skeletal base of the foot includes 3 sections: toes, metatarsus and tarsus.

The design of the toes includes phalanges. Just like the hand, the big toe consists of 2 phalanges, and the remaining 4 fingers - of 3.

There are often cases when the 2 components of the 5th fingers grow together, forming a finger structure of 2 phalanges.

The structure has proximal, distal and middle phalanx. They differ from the phalanges of the hand in that their length is shorter. A clear expression of this is seen in the distal phalanges.

The tarsal bones of the posterior section have talus and calcaneal components, and the posterior section is divided into cuboid, scaphoid and sphenoid bones.

The talus lies at a distance from the distal end of the tibia, becoming the bony meniscus between the bones of the foot and knee.

It consists of a head, neck and body, and is designed to connect with the shin bones, ankle bones and calcaneus.

The calcaneus is part of the posterior lower lobe of the tarsus. It is the largest part of the foot and has a laterally flattened, elongated appearance. At the same time, the calcaneus is the connecting link between the cuboid and talus bones.

The navicular bone is located on the inside of the foot. It has a convex forward appearance with articular components connecting to nearby bones.

The cuboid part is located on the outer side of the foot, articulating with the calcaneus, navicular, cuneiform and metatarsal bones. At the bottom of the cuboid bone there is a groove in which the tendon of the elongated peroneus muscle is laid.

The composition of the sphenoid bones includes:

• Medial.
• Intermediate.
• Lateral.

They lie in front of the scaphoid, inward from the cuboid, behind the first 3 metatarsal fragments and represent the anterior inner part tarsals.

The skeleton of the metatarsus appears in tubular segments, consisting of a head, body and base, where the body is similar to a triangular prism. At the same time, the most long bone- the second, and thickened and short - the first.

Bases of the metatarsal bones equipped with articular surfaces, serving as a connection with the bony components of the tarsus. In addition, it articulates with the adjacent bones of the metatarsus. At the same time, the heads equipped with articular surfaces are connected to the proximal phalanges.

The metatarsal bones are easily palpated due to the fairly thin covering soft tissues. They are placed in multi-angle planes, creating a vault in a transverse line.

Circulatory and nervous systems of the foot

Nerve endings and blood arteries are considered an important component of the foot.

Distinguish 2 main arteries of the foot:

• Rear.
• Posterior tibial.

Also circulatory system includes small arteries that distribute to all tissue areas.

Due to the distance of the arteries of the feet from the heart, circulatory disorders are often recorded due to oxygen deficiency. The results of this manifest themselves in the form of atherosclerosis.

The longest vein that carries blood to the heart area is located at the point of the big toe, extending inside the leg. It is commonly called the great saphenous vein. In this case, the small saphenous vein runs along the outside of the leg.

Placed deep into the legs tibial anterior and posterior veins, and small ones drive blood into large veins. Moreover, small arteries supply tissues with blood, and tiny capillaries connect veins and arteries.

A person suffering from circulatory disorders notes the presence of edema in the afternoon. In addition, varicose veins may appear.

As in other parts of the body, nerve roots in the foot read all sensations and transmit them to the brain, controlling movement.

The nervous system of the foot includes:

1. Superficial fibular.
2. Deep fibula.
3. Posterior tibial.
4. Calf.

Tight shoes can compress any nerve, causing swelling, which will lead to discomfort, numbness and pain.

Diagnostic measures

At the moment when alarming symptoms arise in the foot area, a person comes to an orthopedist and traumatologist, who, knowing complete structure ankle joint, can determine a lot by external signs. But at the same time, specialists prescribe the examination necessary for a 100% correct diagnosis.

Examination methods include:

• X-ray examination.
• Ultrasonography.
• Computed and magnetic resonance imaging.
• Athroscopy.

Detecting pathologies using x-rays is the most cost-effective option. Pictures are taken from several sides, recording possible dislocations, tumors, fractures and other processes.

Ultrasound helps to detect concentrations of blood, find foreign bodies, a possible swelling process in the joint capsule, and also check the condition of the ligaments.

Computed tomography provides a complete examination bone tissue, for neoplasms, fractures and arthrosis. Magnetic resonance imaging is an expensive research technique that provides maximum reliable information about the Achilles tendon, ligaments and articular cartilage.

Athroscopy– a minimally invasive intervention that involves inserting a special camera into the joint capsule, through which the doctor will be able to see all the pathologies of the ankle joint.

After collecting all the information with instruments and hardware, examining doctors and receiving the results of laboratory tests, a accurate diagnosis with the determination of treatment methods.

Pathologies of the ankle and feet

Frequent pain, external changes, swelling and impairment motor functions can serve as signs of foot ailments.

Typically, a person may experience the following diseases:

• Arthrosis in the ankle joint.
• Arthrosis of the toes.
• Valgus change of the thumb.

Arthrosis of the ankle joint is characterized by crunching, pain, swelling, and fatigue during running and walking. This is due to the course of the inflammatory process, which damages the cartilage tissue, leading to typical deformation of joint tissue.

The causes of the disease can be constant increased loads and injuries, provoking the development of dysplasia, osteodystrophy and negative changes in statics.

Treatment is carried out based on the degree of arthrosis with means that reduce pain, restore blood circulation and block the spread of the disease. In difficult cases surgery is performed, relieving the patient of damaged joint segments, restoring mobility and eliminating pain.

Arthrosis of the toes is noted as a result of disruption of metabolic processes and typical blood circulation in the metatarsophalangeal joints. This is facilitated by a lack of moderation in exercise, uncomfortable narrow shoes, injuries, excess weight and frequent hypothermia.

Symptoms of the disease include swelling, deformation of the structure of the fingers, pain during movement and crunching.

On initial stage arthrosis of the fingers, measures are taken to avoid deformation and relieve pain. If an advanced stage is detected, in most cases the doctor prescribes arthrodesis, endoprosthesis replacement or surgical arthroplasty, which should completely solve the problem of the disease.

Hallux valgus, better known as a “bump” at the base of the big toe. This disease is characterized displacement of the head of one phalangeal bone, inclination of the big toe towards the other four, weakening of the muscles and resulting deformation of the foot.

Treatment that inhibits the development of the disease is determined by prescribing baths, physiotherapy, and physical therapy. When the form of changes becomes obvious, an operation is performed, the method of which is determined by the attending orthopedist, taking into account the stage of the disease and general health patient.

The hypodermis smoothes out the unevenness of the organs located under the skin and also has a softening (shock-absorbing) effect. On the other side subcutaneous tissue serves as the body's fat depot and, in addition, since fat is a poor conductor of heat, it helps maintain body temperature. Another function of the hypodermis is to provide mobility to the skin.

The dermis has two layers:

• Reticulate
• Papillary

They are separated by a capillary network.

Located in the dermis sebaceous glands. Between 2 and 6 sebaceous glands surround each hair, depending on the part of the body. Together with the sweat glands, they form a protective film on the surface of the skin (water-lipid mantle), the acidity level of which is slightly shifted to the acidic side - 5.5 (in newborns - 6.5; with physical activity– 4.5). There are no sebaceous glands on the palms and soles.

The dermis and epidermis are separated by a basement membrane - a formation that has a convoluted configuration, thereby providing mechanical adhesion (papillae and processes). The epidermis on the sole contains 5 layers:

• Basal - one row of cylindrical cells lying directly on the basement membrane. These are cells that are in a constant process of division. This layer contains melanocytes - cells that produce the pigment - melanin.
• Prickly - 6 - 8 rows of prismatic to spindle-shaped cells.
• Granular - 2 - 5 rows of spindle-shaped cells.
• Shiny (eleidine) - a layer that is expressed only on the palms and soles.
• Horny - cells are devoid of cellular structures and are completely filled with keratin. They are loosely interconnected and the last row peels off.

The cell cycle (i.e., the time from the formation of a cell in the basal layer to its exfoliation from the surface of the skin) is 20-30 days.

Skin functions:

1. Barrier (from external factors, chemicals, ultraviolet radiation, electricity, infections)
2. Sense organ (deep pressure, touch, cold, heat, UV rays)
3. Thermoregulation (sweating, evaporation, heat transfer)
4. Metabolism (accumulation of substances in the dermis)
5. Breathing (permeability). Human skin, being in water, according to the concentration gradient, releases certain substances into the water. The duration varies depending on age: infants - 5 minutes, adolescents - 10 minutes, adults - 15 minutes.
6. Function of the immune system
7. Endocrine and exocrine function.

Foot structure

The foot is designed for support, acts as a shock absorber, helps maintain balance when changing position, and adapts to uneven ground surfaces. Based on the appearance of the toes, three types of feet are distinguished:

• 60% "Egyptian foot". The thumb is longer than all the others.
• 25% "Quadrangular". The thumb and second finger are the same length.
• 15% "Greek foot". The second finger is longer than the others.

The foot skeleton is divided into 3 sections:

Tarsus. The tarsal bones are seven spongy bones located in two rows, between the tibia and metatarsus. The posterior row is formed by the talus and calcaneus, and the anterior row by the scaphoid, cuboid and three sphenoid bones: medial, intermediate and lateral.

The heel bone is the largest bone in the foot. It is located under the talus and protrudes significantly from under it. The heel tubercle is the main fulcrum lower limb.

The talus tarsus bone, together with the bones of the lower leg, forms the ankle joint.

The metatarsus is made up of five tubular bones. The shortest and thickest is the first metatarsal bone, the longest is the second. The metatarsal bones are divided into a body, a head and a base. The bases of these bones are connected to the bones of the tarsus, and the heads are connected to the bases of the proximal phalanges of the fingers.

Phalanges of the fingers. The toes have three phalanges:

• Proximal.
• Average.
• Distal (end).

The exception is the thumb, the skeleton of which consists of two phalanges:

• Proximal.
• Distal (end).

Phalanxes are tubular bones. The base of each bone has a flattened fossa that forms a joint with a head corresponding to the metatarsal bone. The phalanges do not play a noticeable role in the support function, because they lightly touch the ground.

The tarsal and metatarsal bones do not lie in the same plane. The talus is located on the calcaneus, and the navicular is located above the calcaneus and cuboid. With this mutual arrangement, the arch of the foot is formed, which provides spring support for the lower limb. The arch of the foot has a convexity facing upward. The foot rests on the ground only at several points: at the back is the tubercle of the calcaneus, at the front are the heads of the 1st and 5th metatarsals.

The foot produces the following movements: flexion, extension, abduction, adduction, rotation inward and outward. The muscles of the foot are divided into the muscles of the dorsum of the foot and the muscles of the plantar surface. The muscles of the dorsum of the foot are extensors. The muscles of the sole are flexors.