Bone structure of the leg. Other joints of the foot and their ligamentous apparatus

The ankle is the support of the human skeleton at the bottom of it. It is on him that we rely when we walk, run or do sports. A weight load falls on the foot, and not a moving one, as on the knees. Therefore, it is required to understand the structure of a person's foot, presenting a diagram of it with the designation of ligaments and bones.

This area of ​​the body is considered the distal sphere of the leg - the limb located below. This is a complex articulation of the smallest bones that form a strong arch and serve as a support when we move or stand. The anatomy of the foot, its structure will become clearer if you know the diagram of its structure.

The bottom side of the foot that touches the ground is commonly referred to as the sole, the foot. The reverse side of it is called the back. It is divided into three components:

• digital phalanges;
• metatarsus;
• tarsus.

The arched structure and the abundance of joints give the foot tremendous reliability and strength, moreover, elasticity with flexibility.

Ligaments of the foot

The ligamentous apparatus of the foot and lower leg holds all bone structures between them, protecting the joint and limiting its movement. Anatomically, these structures are divided into three sets.

The first of them includes fibers that connect the shins to each other. The interosseous is the region of the membrane located below, stretched between the shin bones in its entire length. The posterior lower one is designed to impede the internal movements of the bones. The anterior peroneal lower goes to the ankle, located outside, from the tibial bone, holding the ankle from turning outwards. The transverse ligament fixes the foot against inward movement. These fibers attach the fibula to the tibia.

The external ligaments are represented by the anterior and posterior talus peroneal, as well as the calcaneofibular. They go from the outer region of the fibula, scattering in all possible directions to the parts of the tarsus. Therefore, they are called the "deltoid ligament". They are designed to reinforce the outer edge of the area.

The next group includes the internal ligaments that run to the side of the joint. The tibial scaphoid, tibial ligament of the heel, posterior and anterior tibial talus ligaments were introduced here. They start at the ankle from the inside. Designed to restrain the tarsal bones from displacement. The most powerful bunch does not stand out here - they are all quite strong.

Foot bones

The foot ligaments are always attached to the bones. From the rear of the tarsus, the calcaneal with the ram is placed, in front - the three wedge-shaped, cuboid and scaphoid. The talus bone is located between the calcaneus and the distal end of the tibia, connecting the foot to the lower leg. She has a head with a body, between them, in turn, a narrowing, a neck.

On top of this body is the articular region, a block that serves as a connection to the tibia. A similar surface is present on the head, in front of it. It articulates it with the scaphoid bone.

It is curious that on the body, outside and inside, articular elements are found that articulate with the ankles. There is also a deep furrow in the lower area. It separates the articular elements that articulate it with the calcaneus.

The calcaneus refers to the posterior inferior part of the tarsus. Its shape is somewhat elongated and flattened on the sides. It is considered the largest in this area. The body and the bump are distinguished in it. The latter is well felt.

There are articular components on the bone. They articulate it with bones:

• from the ram - at the top;
• with a cuboid - in front.

From the inside on the calcaneus there is a protrusion that serves as a base for the talus bone.

The scaphoid is located near the inner end of the foot. It is located in front of the ram, inside cuboid and wedge-shaped bones. On its inner area, a tuberosity was found, looking down.

Feeling well under the skin, it is an identifying point that allows you to determine the height of the inner region of the longitudinal foot arch. It is convex anteriorly. There are articular areas here as well. They articulate with nearby bones.

The cuboid bone is located at the outer part of the foot, articulating:

• in front - with the 5th and 4th metatarsal;
• behind - with a heel;
• from the inside - from the outer wedge-shaped and scaphoid.

A furrow runs along it from the lower side. This is where the peroneal longus tendon is located.

In the tarsus, the anteroposterior compartment includes the wedge-shaped bones:

• lateral;
• intermediate;
• medial.

They are located in front of the scaphoid, behind the 1st triplet metatarsal and inwardly relative to the cuboid bone.

In the five metatarsal bones, each is tubular. All stand out:

• head;
• body;
• base.

Any representative of this group with a body resembles an outwardly 3-sided prism. The longest in it is the second, the first is the thickest and shortest. On the bases of the metatarsal bones are the articular areas, articulating them with other bones - the nearest metatarsal, as well as the tarsal.

On the heads there are areas of joints articulating them with the proximal phalanges located in the fingers. Any of the metatarsal bones can be easily felt from the back. Soft tissues cover them with a relatively small layer. All of them are located in different planes, creating a vault in the transverse direction.

In the foot, the toes are divided into phalanges. Like a hand, the first toe has a pair of phalanges, and the rest have three phalanges. Often, in the fifth finger, a pair of phalanges grow together into a single whole and, ultimately, not a three, but a pair remains in its skeleton. Phalanges are divided into distal, middle and proximal. The fundamental difference between them on the legs is that they are shorter than on the arms (distal in particular).

Like the hand, the foot has sesamoid bones - and much more pronounced. Most of them are observed in the area where the 5th and 4th metatarsal bones are associated with the proximal phalanges. Sesamoid bones enhance the transverse vaultedness in the anterior part of the metatarsus.

The ligaments in the foot also attach to the muscles. A pair of muscles is located on its back surface. We are talking about short extensors of the fingers.

Both extensors start from the inner and outer spheres of the calcaneus. They are attached to the proximal digital phalanges, which correspond to them. The main work of these muscles is to extend the toes on the foot.

The muscles and ligaments of the foot are diverse. There are three muscle groups located on the surface of the sole. The internal group includes the following muscles that are responsible for the work of the thumb:

• the one that takes him away;
• short flexor;
• the one that leads him.

All of them, starting from the bones of the tarsus and metatarsus, are attached to the big toe - the base of its proximal phalanx. The functionality of this group is clear from the definitions.

The outer muscle group of the foot is everything that affects its fifth toe. We are talking about a pair of muscles - the short flexor, as well as the one that abducts the little finger. Each of them is attached to the 5th toe - namely, to its proximal phalanx.

The most important among the groups is the middle one. Includes muscles:

• short flexor for the fingers, from the second to the fifth, attached to their middle phalanges;
• square plantar, attached to the tendon;
• worm-like;
• interosseous - plantar and dorsal.

The direction of the latter is to the proximal phalanges (from the 2nd to the 5th).

These muscles start on the metatarsal bones from the tarsus on the plantar region of the foot, except for the worm-like muscles, which start from the long digital flexor tendons. All muscles are involved in various finger movements.

In the plantar region muscle stronger than the back. This is due to different functional features. In the plantar region, the muscles hold the arches of the foot, to a large extent ensuring its spring qualities.

A total of 26 bones in the foot + from 2 sesamoid (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, metatarsus, metatarsus, its central section and fingers, digiti, representing the distal section.

Bones of the foot.

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

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 departs from the head - the neck, collum tali, connecting the head to the body. The protruding part of the body with three articular surfaces is called a block, trochlea tali. Of these three articular surfaces, the upper, 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 behind the block of the talus. It is divided by the sulcus tendon of the long flexor of the big toe, sulcus tendinis T. 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 back, facies articularis calcanea posterior, and the front, facies articularis calcanea anterior.

Talus.

Calcaneus calcaneus, is the most massive of the bones of the foot. In it, a body is distinguished, corpus calcanei, ending in the back with a heel tuber, 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 the posterior and anterior articular surfaces corresponding to those of the talus, facies articularis talaris posterior et anterior, while the anterior, 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 tarsal sinus, sinus tarsi, which opens on the body of the bone from the lateral side. Sustentaculum tali departs from the body of the calcaneus from the medial side. It supports the head of the talus. On its lower surface there is the already mentioned groove, sulcus tendinis T. 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 peroneal block, trochlea peronealis. Under it passes the groove of the tendons of the peroneal muscles, sulcus tendinis v. peronei. At the front end of the body there is another articular platform for articulation with the cuboid bone, facies articularis cuboidea.

Calcaneus.

Scaphoid, os naviculare, so named because it resembles a boat in shape, 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 to the three sphenoid bones. This surface is divided by ridges into three unequal articular sites 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 posterior tibial 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.

Internal, median, external sphenoid bones.

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

Os cuneiforme intermedium is the smallest of the three sphenoid bones in size, and the shape most closely matches the wedge. Unlike the previous bone, its base faces the back of the foot, and the 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 adjacent wedge-shaped ones.

Os cuneiforme laterale - in comparison with the previous ones, it is medium in size, has a regular wedge-shaped shape, with the base facing the back of the foot, and the top towards the sole. It has the following articular platforms: behind - for os naviculare, in front - for os metatarsale III, with inside- for os cuneiforme intermedium and os metatarsale II, from the outside - for os cuboideum.

Internal, median, external wedge-shaped and cuboid bones.

Cuboid, os cuboideum, is located along the lateral edge of the foot between the heel bone in the back, IV and V metatarsal bones in front, therefore there are two articular platforms on its front surface, and one on the back. The inner surface is in contact with the lateral sphenoid and scaphoid bones, therefore it 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 the articular surfaces. On the plantar side there is a tuberosity, tuberositas ossis cuboidei, in front of which there is a groove for the passage of the tendon of the long peroneal muscle, sulcus tendinis musculi peronei longi.

Bones are metatarsus... Metatarsus, tarsus, consists of five short tubular bones with a body, corpus, head, caput, and base, basis. The bones of the metatarsus are similar in shape and structure, but differ in size: the first metatarsal bone (located on the side of the thumb) 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, significantly compressed from the sides. The bodies are prismatic, curved in the sagittal plane, convex to the rear. The bases of the metatarsal bones are articulated with the bones of the distal row of the tarsus and are provided with characteristic articular surfaces. The os metatarsale I head is divided from the plantar side by a ledge 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, on the base there is tuberosity, tuberositas ossis metatarsalis I. The bases of os metatarsale II and III resemble a wedge, with the tip facing downward. 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 short peroneal muscle is attached.

1, 2, 3, 4, 5 metatarsal bones.

The bones of the metatarsus and tarsus do not lie in the same plane, but form longitudinal arches, convex upward. As a result, the foot rests on the ground only with some points of its lower surface: behind the fulcrum is the calcaneal tubercle, in front - the heads of the metatarsal bones. The phalanges of the fingers only touch the support area. According to the bones of the metatarsus, there are five longitudinal arches of the foot. Of these, the arches do not touch the support plane under load on the foot, I-III arches, therefore, they are spring; IV and V - adjacent to the support area, they are called support. In connection with different forms and the convexity of the longitudinal vaults, the lateral edge of the foot (IV-V vaults) descends to the support area, the medial edge (I-III vaults) has a pronounced arched shape.

In addition to the longitudinal vaults, there are two transverse vaults (tarsal and metatarsal), located in the frontal plane, convex 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 vault, the support planes touch the heads of only the first and fifth metatarsal bones.

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

Phalanges of toes... The skeleton of the toes is similar to the skeleton of the fingers of the hand, that is, it consists of phalanges, phalanges digitorum pedis, the number, shape and names of which are the same as on the hand (I toe, hallux, also has only two phalanges). The phalanges of the first toe are thicker; in the rest of the fingers their sizes are much smaller, especially the short phalanges in the fourth and fifth fingers. In the little finger, the middle and distal (nail) phalanges often grow together. The body of the proximal phalanges is much thinner in comparison with the middle and distal ones, and is close to a cylinder in shape.

On the foot, as well as on the hand, there are sesamoid bones. They are located permanently in the metatarsophalangeal joints of the thumb and little finger, and in the interphalangeal joint of the thumb. In addition to the named sesamoid bones, there are also inconsistent bones in the tendons of m. peroneus longus et m. tibialis posterior.

FOOT BONE CONNECTIONS

All joints 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) the joints between the bones of the tarsus - articulationes subtalaris, talocalcaneonavicularis, calcaneocuboidea, cuneonavicularis, intertarseae;

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

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

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

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

The medial (deltoid) ligament, ligamentum mediale, includes four parts: the tibial-navicular part, pars tibionavicular, the anterior and posterior tibial-talus parts, partes tibiotalares anterior et posterior, and the tibial-calcaneal part, pars tibiocalcanea.

On the lateral side, the joint capsule is reinforced with 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 ankle joint is typical block-shaped in shape. In it, movements around the frontal axis are possible: plantar flexion; extension (dorsiflexion). Due to the fact that the talus block at the rear is narrower, lateral swinging movements are possible with maximum plantar flexion. Movements in the ankle joint are combined with movements in the subtalar and talocalcaneal-navicular joints.

BONE CONNECTIONS ARE PRELIMINARY. The joints of the tarsal bones are represented by the following joints: subtalar, talocalcaneonavicular, calcaneal-cuboid, 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 and the posterior talar articular surface, facies articularis talaris posterior, on the calcaneus. The joint is cylindrical, movements are possible in it only around the sagittal axis.

The talocalcaneonavicular joint, articulatio talocalcaneonaviculars, has a spherical shape. The articular head and cavity are distinguished in it. 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 articular cavity is formed by the posterior articular surface, facies articularis posterior, scaphoid bone and anterior talar articular surface, facies articularis talaris anterior, calcaneus. The articular capsule is attached along the edges of the articular surfaces.

Subtalar, talocalcaneal-navicular, calcaneo-cuboid, 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 is involved in the formation of the glenoid cavity. When it is stretched, the head of the talus is lowered and the foot is flattened. On the dorsal surface, the joint is strengthened by the talonavicular ligament, ligamentum talonavicular. This ligament connects the dorsum of the talus neck and the scaphoid. On the sides, the joint is reinforced with 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 ribbon, has an oblique direction of fibers and goes 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 tarsal sinus, sinus tarsi, is filled with a very strong interosseous talocalcaneal ligament, ligamentum talocalcaneum interosseum.

Despite the fact that the talocalcaneonavicular joint is spherical in the 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 (somewhat lower and posterior to the place of attachment of the ligamentum calcaneofibulare). This axis also serves as an axis for the articulatio subtalaris. Consequently, both joints function as a combined talo-tarsal joint, articulatio talotarsalis. In this case, the talus remains motionless, and together with the calcaneus and scaphoid bones, the entire foot moves.

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

Thus, during foot movements, 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 in the first year of life), the foot is in a supinated position, therefore, when walking, the child places the foot on its lateral edge.

The ankle joint (supratar joint), subtalar and talocalcaneonavicular joints (articulatio talotarsalis) can function independently. In the first, flexion and extension prevail, 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 heel-cuboid joint, articulatio calcaneocuboidea, is formed by articular surfaces: facies articularis cuboidea calcanei and fades articularis posterior ossis cuboidei.

The articular surfaces are saddle-shaped. From the medial side, the articular capsule is thick, strong and taut, from the lateral side it is thin and free. The capsule is reinforced with ligaments, which are especially developed from the plantar side. The most durable of these is the long plantar ligament, ligamentum plantare longum. This ligament starts from the bottom roughness of the calcaneus and consists of several layers. Its deep tufts attach to the 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 attach to the bases of 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 the areas of the plantar surfaces of the calcaneus and cuboid bones.

The calcaneal-cuboid joint is saddle-shaped in shape, but functions as a uniaxial rotational joint, combined with the talocalcaneal-navicular and sub-talar joints.

From a surgical point of view, articulatio calcaneocuboidea and articulatio talonavicularis (part of the articulatio talocalcaneonaviculars) are considered as one joint - the transverse joint of the tarsus articulatio tarsi transversa (Choparov 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 dissect a special bifurcated ligament, the ligamentum bifurcatum (Choparov's key of the joint), which holds the calcaneus, scaphoid and cuboid bones relative to each other. Ligamentum bifurcatum (bifurcated ligament) begins at the upper edge of the calcaneus and is divided into two ligaments: calcaneonavicular, ligamentum calcaneonaviculare, and calcaneo-cuboid, ligamentum calcaneocuboideum. The calcaneonavicular ligament is attached at the posterolateral edge of the os naviculare, and the calcaneal-cuboid ligament is attached to the dorsum of the cuboid bone.

The wedge-shaped 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 areas of the sphenoid, cuboid and scaphoid bones facing each other. The joint cavity has the form of a frontal gap, from which one process moves back (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 along 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 wedge-shaped ligaments, ligamenta cuneonavicularia plantaria et dorsalia, interosseous intercuneiform ligaments, ligamenta intercuneiformia interossea, dorsal and plantar intercuneiform ligaments, ligamenta intercuneiformia dorsalia etplantaria. The interosseous ligaments can only be seen on a horizontal cut of the foot or on an exposed joint when the articulating bones are pushed apart. The joint is typically flat, with little movement between the bones.

PREPOSITAL JOINTS. The joints between the tarsal and metatarsal bones (articulationes tarsometatarseae) are flat joints (only in the articulation of the first metatarsal bone there are weakly expressed saddle surfaces). There are three of these joints: the first is 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 from a surgical point of view are combined into one joint - the Lisfranc joint, which is also used to isolate the distal part of the foot. Joint capsules are reinforced with 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 sphenoid-metatarsal ligament, which is stretched between the medial sphenoid bone and the second metatarsal bone, is the key of the Lisfranc joint. The tarsometatarsal joints are flat in shape, inactive.

The intermetatarsal joints, articulationes intermetatarseae, are formed by the surfaces of the metatarsal bones facing each other. Their capsules are reinforced with the dorsal and plantar metatarsal ligaments, ligamenta metatarsea dorsalia et plantaria. There are also interosseous metatarsal ligaments, ligamenta metatarsea interossea.

On the foot, as well as on the hand, it is possible to distinguish a solid base, that is, a complex of bones that are connected to each other almost motionlessly (movements are minimal here). The solid base of the foot includes a greater number of bones (10): os naviculare; ossa cuneiformia mediale, intermedium, laterale; os cuboideum; 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 fossa of the bases of the proximal phalanges. The articular surfaces of the ossa metatarsalia II-V heads have an irregular spherical shape: the plantar part of the articular surface is significantly flattened. The articular fossa of the phalanges are oval in shape. The capsule of the joints is free, attached at the edge of the articular cartilage; on the back, it is very thin. From the lateral and medial sides, the joints are supported by collateral ligaments, ligamenta collateralia. On the plantar side, the joints are reinforced with plantar ligaments, ligamenta plantaria (these ligaments sometimes contain the inclusion of fibrous cartilage and sesamoid bones). Here is the deep transverse metatarsal ligament, ligamentum metatarseum transversum profundum. It is a fibrous cord, which is located transversely between the heads of the I-V metatarsal bones and grows together 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 differs in some peculiarities: two sesamoid bones are permanently enclosed in the plantar part of the capsule of this joint, which correspond to two grooves on the articular surface of the head of os metatarsale I. Therefore, the metatarsophalangeal joint of the thumb functions as a blocky joint. It carries out flexion and extension around the frontal axis. The joints of the other four fingers function as ellipsoidal. In them, flexion and extension around the frontal axis, abduction and adduction around the sagittal axis are possible, and in a small volume - a circular motion.

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

The human ankle joint is the pivot point of the bone skeleton of the lower limb. It is this articulation of a person that accounts for the weight of the body while walking, playing sports, running. The foot of the leg, in contrast to the knee joint, holds the load with weight, not movement, this is reflected in the features of its anatomy. The structure of the ankle joint of the leg and other parts of the foot is of great clinical importance.

Human foot anatomy

Before considering the structure of different parts of the foot, it must be said that in this part of the leg, muscle elements, ligamentous structures and bones interact organically.

In this case, the bone skeleton of the foot is divided into phalanges of fingers, metatarsus and tarsus parts... The bones of the tarsus are connected in the ankle joint with the elements of the lower leg.

In the tarsus, one of the largest bones is the talus. On the top is a ledge called block... This element is connected from all sides to the tibia and fibula.

In the lateral elements of the articulation are bony outgrowths called the ankles. The outer is part of the fibula, and the inner is the tibia. Each surface of the bone joint has hyaline cartilage, which plays a shock-absorbing and nourishing role ... The articulation is:

• By the process of movement - biaxial.
• It is block-shaped in shape.
• The structure is complex (more than 2 bones).

Ligaments

Restriction of movements in the human joint, protection, retention of bone structures with each other are possible due to the presence of ligaments of the ankle joint of the leg. The description of these elements must begin with the fact that these structures in anatomy are divided into three groups... The first group includes the fibers that connect the shin bones to each other:

• Lower posterior ligament- the part that prevents the internal rotation of the lower leg bones.
• The interosseous ligament is the lower part of the membrane, which is stretched between the bones of the lower leg along its entire length.
• The transverse ligament is a small fibrous part that provides fixation of the foot from turning inward.
• Inferior anterior peroneal ligament. The fibers in this part are directed from the outer ankle to the tibia and help keep the foot from turning outward.

In addition to the above functions of the fibers, they also provide anchoring of the powerful tibia to the fragile fibula. The next group of human ligaments are outer side fibers:

• Calcaneal fibular.
• Posterior talus peroneal.
• Anterior talus peroneal.

These ligaments begin at the outer peroneal malleolus of the bone and diverge in different directions towards the tarsal parts, therefore they are summarized by such a term as "deltoid ligament". The function of these structures is to reinforce the outer edge of a given part.

The third group is lateral internal ligaments:

• Tibial calcaneus.
• Tibial scaphoid.
• The talar posterior tibial.
• Talon anterior tibial.

Similar to the anatomy of the above fiber groups, these ligaments keep the tarsal bones from displacement and start at the inner ankle.

Muscle

Additional fastening of elements, movements in the joint are achieved with the help of muscle elements that surround the ankle joint of the leg. Any muscle has a specific anchor point on the foot and its purpose, but the structures can be arranged in groups according to the main function.

The muscles that are involved in flexion are the plantar, tibial posterior, long flexors of the thumb, triceps. The extensor longus of the thumb and the anterior tibial muscle are responsible for the extension function.

The third group is called pronators - these fibers rotate the ankle joint inward towards the middle part. These muscles are the long and short peroneal muscles. Their antagonists are the peroneal anterior muscle, the long extensor of the thumb.

Achilles tendon

The ankle in the posterior region is fixed by the largest Achilles tendon in the human body. The joint is formed when the soleus and calf muscles at the bottom of the lower leg.

A powerful tendon stretched between the calcaneal tuberosity and the muscle abdomen has an important function while driving.

An important clinical point is the likelihood of sprains and ruptures of this structure. At the same time, in order to restore function, the traumatologist is obliged to carry out complex treatment.

Blood supply

Metabolic processes, recovery of elements after injury and stress, the work of muscles in the joint is possible due to the special anatomy of the blood supply that surrounds the connection. The arrangement of the ankle arteries is similar to the blood supply to the knee of the leg.

The posterior and anterior peroneal and tibial arteries branch out in the region of the inner and outer ankles and capture the joint from all sides. Due to this device, the arterial network occurs normal work this is the anatomical part.

Venous blood departs from this part along the internal and external networks, which form important connections: tibial and saphenous internal veins.

The rest of the ankle joints

The ankle connects the bones of the foot to the lower leg, but small parts of the lower limb are also connected to each other connected by small joints:

Such a complex anatomy human foot helps her to maintain a balance between support function and leg mobility, which is important for a person's direct walking.

Functions

The ankle structure of the leg is primarily aimed at achieving the mobility that is required when walking. Due to the well-coordinated work in the muscle joint, movement can be performed in two planes. Ankle joint in the frontal plane does extension and flexion... V vertical axis rotation can occur: in a small volume outward and inward.

In addition, due to the soft tissues of this area, which keeps the bone structures intact, the movements are cushioned.

Diagnostics

In the ankle joint, the legs can undergo various pathologies. To visualize a defect, identify it, correctly establish a diagnosis, there is different ways diagnostics:

• Ultrasound... Today it is rarely used, because, unlike the knee joint, the cavity of the ankle joint is small. But this method is distinguished by the absence of a negative effect on the tissue, by the speed of its implementation, and by its efficiency. You can define foreign bodies, edema and accumulation of blood in the joint capsule, visualize the ligaments.
• Atroscopy... Low-traumatic and minimally invasive procedure, including the introduction of a video camera into the capsule. The doctor will be able to look at the surface of the bag with his own eyes and identify the focus of the disease.
• X-ray... The most affordable and economical survey option. In different projections, images of the ankle joint are taken, where it is possible to identify a tumor, dislocation, fracture and other processes.
• MRI... This procedure is better than any other to determine the condition of the Achilles tendon, ligaments, articular cartilage. The method is quite expensive, but the most effective.
• CT scan ... This method is used to assess the condition of the articular skeletal system. With arthrosis, neoplasms, fractures this way is the most accurate in terms of diagnosis.

Instrumental methods are complemented by results laboratory research and medical examination, based on this information, the specialist determines the diagnosis.

Ankle joint pathologies

Alas, even a strong ankle is prone to injury and disease. The most common diseases of the ankle joint are:

• Arthritis.
• Osteoarthritis.
• Achilles tendon ruptures.
• Injuries.

How to identify the disease? What to do and which doctor should I contact? It is necessary to understand all the listed diseases.

With this disease, due to a lack of calcium, trauma, frequent overstrain, degeneration of cartilaginous structures and bones develops. Over time, outgrowths are formed on the bones - osteophytes, which disrupt the range of motion.

Disease manifested by mechanical pain... This means that symptoms increase in the evening, decrease at rest, and increase after exertion. Stiffness in the morning is absent or short-term. There is a gradual decrease in the mobility of the ankle.

With these signs it is necessary to contact a therapist. If complications develop, he will send for a consultation with another doctor.

Arthritis

Inflammatory processes of the joint can occur during the development of rheumatoid arthritis or infection in the cavity. Also, the ankle can become inflamed with gout as a result of the deposition of uric acid salts.

The disease manifests itself joint pain in the morning and towards the end of the night... When moving, the pain subsides. Symptoms are removed with the help of anti-inflammatory drugs (Diclofenac, Nise, Ibuprofen), as well as after the application of gels and ointments to the area of ​​the ankle joint. You can also determine the pathology by the simultaneous defeat of the joints of the hand and knee joint.

This disease is dealt with by rheumatologists, they recommend basic drugs to eliminate the symptoms of the disease. Each disease has its own drugs designed to stop the inflammatory process.

The most important thing is to distinguish infectious arthritis from other causes... As a rule, it manifests itself with severe symptoms with edema syndrome and intense pain. Pus collects in the joint cavity. Hospitalization of the patient is often necessary, bed rest is required, and treatment is carried out with antibiotics.

Trauma

During a direct trauma to the ankle at work, in an accident, in sports, various tissues of the articulation can be damaged. Damage can cause a violation of the integrity of the tendons, ligament rupture, bone fracture.

Common features are: swelling, pain after injury, inability to step on lower limb, decreased mobility.

After an ankle injury, it is necessary to ensure the rest of the limb, apply ice to this place, and then consult a doctor. After examination and research, a traumatologist will prescribe a set of medical procedures.

Typically, therapy includes immobilization(immobilization of the joint), as well as the appointment of painkillers and anti-inflammatory drugs. Sometimes it may be required surgery, it can be performed using arthroscopy or the classical way.

Achilles tendon rupture

With a direct impact on the back surface of the ankle, with a fall on the leg, during sports loads, a rupture of the Achilles tendon can occur. In this case, a person cannot straighten his foot, stand on his toes. In the area of ​​the leg injury, blood accumulates, edema forms. Joint movements are very painful.

In the end, I would like to note that the control of the leg muscles occurs due to nervous system... If the joints and muscles are without stress, then they gradually atrophy, while when the joints work for a long time without rest, then their fatigue inevitably comes. After resting, the joints of the legs are toned, and their working capacity is restored. Therefore, doctors recommend taking breaks more often between heavy physical work.

The foot, which not everyone knows, performs important functions. If it deforms, then people cannot move normally, their capabilities are limited. Knowing, you can determine what exactly hurts in case of any damage. And this can make it easier to carry out first aid.

The human foot is formed by three sections: the tarsus, metatarsus and toes. The anatomy of each section is special and consists of several bones.

The tarsus consists of the talus, calcaneal navicular, cuboid and sphenoid bones. The talus serves as the connection between the leg and foot. It has the following structure: body, head and neck. The talus block is needed to connect the tibia and tarsus. The calcaneus, the lower back of the tarsus, is the largest of all bones in the foot. The scaphoid bone makes it easier to determine the height of the arch of the foot. The cuboid bone connects all the bones of the tarsus. The anterior section consists of sphenoid bones.

The metatarsus is formed by five bones. They all have a tubular shape. The second is the longest and the first is the thickest. They are easy to feel, as they are covered with a thin skin layer on top.

The fingers are composed of phalanges. The thumb is formed by two phalanges, and the rest by three. Sometimes the phalanges of the little finger grow together, so only two phalanges are visible on the x-ray.

Ligamentous apparatus

The mobility of a human foot is due to the fact that it consists of several joints: ankle, subtalar, talocalcaneonavicular, tarsometatarsal, metatarsophalangeal and interphalangeal. Each of these joints has a specific function.

Ankle joint

The structure of the ankle joint is as follows: it also consists of the talus. It has a block-like shape. The structure scheme allows him to perform the following movements: flexion and extension. Moreover, the angle between the two extreme points reaches 90 °.

At the back of the joint, the talus block narrows slightly, so during flexion of the foot, it is adducted and abducted. The surface of the ankle is covered with many ligaments and tendons that perform it protective function... From the inside, there are ligaments extending from the medial ankle. But outside the ankle is strengthened with the help of the ligaments coming from the fibula.

The anatomy of this joint has its own characteristics. So, at birth, it bends more strongly towards the back of the foot, and in adults, on the contrary, into the plantar.

It consists of the heel and talus. It has a cylindrical shape. Has a low degree of mobility. From above it is covered with ligaments, due to which the joint is protected from various injuries.

Talocalcaneonavicular joint

The anatomy of this joint is as follows: includes the talus, calcaneus and scaphoid bones. The movements occur simultaneously with the subtalar joint, since they are articulated with the help of ligaments. With age, the arch of the foot descends. Therefore, it is not uncommon for a one-year-old child who is just starting to walk, placing the foot not on the entire surface, but only on the front toes.

Tarsometatarsal joints

The diagram of the human foot shows that such joints are located between the bones of the metatarsus and tarsus. They are small in size, predominantly flat in shape. Their mobility is limited. Due to the fact that numerous ligaments pass along the surface of each joint, the bones of the metatarsus are almost tightly connected to each other, forming a solid base of the foot.

Metatarsophalangeal joints

The diagram of the structure of the human foot also includes the metatarsophalangeal joints, which have spherical shape and low mobility. Their formation occurred as a result of the fusion of the heads of the bones of the metatarsus and the bases of the phalanges. The need for such a joint is that it provides flexion and extension of the fingers. Top they are covered big amount ligaments. The interphalangeal joints are located between the phalanges of the fingers. If on the hands they have conditional mobility, then on the legs such joints are practically motionless.

Muscle

It consists not only of bones and joints, but also muscles. They are attached with tendons to various bones on the surface of a person's foot. As a rule, the beginning of the muscles of the foot occurs from the lower leg. The upper part of the foot consists of two muscles, and each of them has its own functions: one extends the toes, the other extends the big toe. They take their origin from the inner surface of the heel.

The plantar side of the foot includes several muscles: internal, external and middle. The need for internal muscles is that they condition the movement of the big toe of a person's foot. The origin of the muscles comes from the bones of the metatarsus.

The peculiarity of the external muscles is that they act on the fifth toe of the foot - the little finger. They include two muscles: one - removes the finger, the second - bends it. They are attached to the phalanx of the last toe.

The middle muscle group includes the most important and important muscles. Indeed, with their help, several fingers are set in motion at once (2, 3, 4). The function of the muscles is the process of flexion, pinching and spreading of the toes.

Why does flat feet develop?

The anatomy of the foot includes a huge number of bones and muscles. And if at least one of them is deformed, then various violations occur in the work of a person's foot. Flat feet is a disorder caused by deformation of the arches. With this disease, the arches of the feet become flat, and the surface of the heel deviates towards the outer region.

Moreover, the deformation of the foot occurs in such a way that the metatarsal bone deviates, so the position of the big toe changes. And if you wear too tight shoes, your toes will start to overlap. As a result, a common disease appears, which is popularly called the "bone" of the thumb. To check for flat feet, a special circuit or tests can be used.

So, it is necessary to check the height of the longitudinal arch. It can be easily felt at the top of the inner vault. In addition, you should determine the approximate angle of deflection of the thumb. The degree of deformation largely depends on this angle.

You can also check to see if your foot is shaped like a bear's paw. To do this, wet the foot and step on a dry place with it. If the print is solid, without bending, then most likely you have flat feet.

Flat feet also have a number of symptoms. Often, people with this disease get tired very quickly, even after a five-minute walk. Calluses and corns often appear on the surface of the foot, which pass rather slowly. Pain and discomfort may be felt in the foot. It is hard for women to walk in high-heeled shoes. If you suspect the development of flat feet, you should definitely contact a specialist.

Indeed, otherwise, a number of pathologies may occur. If the foot deviates, this can cause the lower leg to rotate. In addition, it plays an important role in shaping posture. Usually, a person with flat feet has scoliosis or even kyphosis.

Thus, the diagram of the structure of the human foot includes not only bones, but also ligaments, tendons, muscles. Each of them performs specific functions. If there is a deformation of some part, then the work of the entire foot may be disrupted.... Therefore, you must definitely go to an appointment with a specialist.

In the tarsus region, tarsus, are represented by the following bones: talus, calcaneus, scaphoid, three sphenoid bones: medial, intermediate and lateral, and cuboid. The metatarsus, metatarsus, includes 5 metatarsal bones. Phalanges, phalanges, toes are named the same as the phalanges of the fingers.

Tarsal bones, ossa tarsi, are arranged in two rows: the talus and calcaneus belong to the proximal, and the scaphoid, cuboid and three sphenoid bones to the distal. The bones of the tarsus are articulated with the bones of the lower leg; the distal row of tarsal bones articulates with the metatarsal bones.

Talus, talus, - the only one of the bones of the foot, which articulates with the bones of the lower leg. Its posterior section is the body of the talus, corpus tali. Anteriorly, the body passes into a narrowed area of ​​the bone - the neck of the talus, collum tali; the latter connects the body to the forward head of the talus, caput tali. The talus bone from above and on the sides in the form of a fork is covered by the bones of the lower leg. An ankle joint, articulatio talocruralis, is formed between the bones of the lower leg and the talus. Accordingly, the articular surfaces are: the upper surface of the talus, facies superior ossis tali, having the shape of a block - the talus block, trochlea tali, and lateral, lateral and medial, ankle surfaces, facies malleolaris lateralis et facies malleolaris medialis. The upper surface of the block is convex in the sagittal direction and concave in the transverse direction.

The lateral and medial malleolar surfaces are flat. The lateral ankle surface extends to the upper surface of the lateral process of the talus, processus lateralis tali. The posterior surface of the body of the talus from top to bottom is crossed by the groove of the long flexor of the big toe sulcus tendinis m. flexoris hallucis longi. The groove divides the posterior edge of the bone into two tubercles: the larger medial tubercle, tuberculum mediale, and the smaller lateral tubercle, tuberculum laterale. Both tubercles, separated by a groove, form the posterior process of the talus, processus posterior tali. Lateral tubercle of the posterior process of the talus

bone sometimes, in the case of its independent ossification, is a separate triangular bone, os trigonum.

On the lower surface of the body in the posterolateral region there is a concave posterior calcaneal articular surface, facies articularis calcanea posterior. The anteromedial parts of this surface are limited by the groove of the talus, sulcus tali, which runs here from behind to front and laterally. Anterior and outward of this groove is the middle calcaneal articular surface, facies articularis calcanea media. Anterior calcaneal articular surface, facies articularis calcanea anterior, lies in front of it.

Through the articular surfaces, the lower part of the talus articulates with the calcaneus. On the front of the head of the talus there is a spherical scaphoid articular surface, facies articularis navicularis, through which it articulates with the scaphoid bone.

Heel bone, calcaneus, located downward and posterior to the talus. The posterior lower part of it is formed by a well-defined tubercle of the calcaneus, tuber calcanei. The lower parts of the tubercle from the lateral and medial sides pass into the lateral process of the tuberosity of the calcaneus, processus lateralis tuberis calcanei, and into the medial process of the tuberosity of the calcaneus, processus medialis tuberis calcanei. On the lower surface of the tubercle there is a heel tubercle, tuberculum calcanei, located at the anterior end of the line of attachment of the long plantar ligament, lig. plantare longum.

On the front surface of the calcaneus there is a saddle-shaped cuboid articular surface, facies articularis cuboidea, for articulation with the cuboid bone.

In the anterior part of the medial surface of the calcaneus, there is a short and thick process - the support of the talus, sustentaculum tali. The groove of the long flexor tendon of the big toe, sulcus tendinis m, runs along the lower surface of this process. flexoris hallucis longi.

On the lateral surface of the calcaneus, in the anterior section, there is a small peroneal block, trochlea fibularis, behind which passes the groove of the tendon of the long peroneal muscle, sulcus tendinis m. peronei (fibularis) longi.

On the upper surface of the bone, in the middle section, there is an extensive posterior talar articular surface, facies articularis talaris posterior. In front of it lies the groove of the calcaneus, sulcus calcanei, which runs from back to front and laterally. Anterior to the groove, along the medial edge of the bone, there are two articular surfaces: the middle talar articular surface, facies articularis talaris media, and in front of it - the anterior talar articular surface, facies articularis talaris anterior, corresponding to the surfaces of the same name on the talus. When the talus is applied to the calcaneus, the anterior sections of the talus groove and the calcaneus groove form a depression - the tarsal sinus, sinus tarsi, which is felt as a slight depression.

Scaphoid, os naviculare, flattened in front and behind, lies in the area of ​​the inner edge of the foot. On the posterior surface of the bone there is a concave articular surface, through which it articulates with the articular surface of the head of the talus. The upper surface of the bone is convex. The anterior surface of the bone carries an articular surface for articulation with three sphenoid bones. The boundaries that define the places of articulation of the scaphoid with each sphenoid bone are small combs.

On the lateral surface of the bone there is a small articular surface - the place of articulation with the cuboid bone. The lower surface of the scaphoid is concave. In its medial section, there is the tuberosity of the scaphoid, tuberositas ossis navicularis.

Sphenoid bones, ossa cuneiformia, in the amount of three, I are located in front of the scaphoid. Distinguish between medial, intermediate and lateral sphenoid bones. The intermediate sphenoid bone is shorter than the others, therefore the anterior, distal, surfaces of these bones are not at the same level. They have articular surfaces for articulation with the corresponding metatarsal bones,
The base of the wedge (the wider part of the bone) in the medial sphenoid bone is directed downward, and in the intermediate and lateral - upward.

The posterior surfaces of the sphenoid bones have articular platforms for articulation with the scaphoid bone.
The medial sphenoid bone, os cuneiforme mediale, on its concave lateral side bears two articular surfaces for articulation with the intermediate sphenoid bone, os cuneiforme intermedium, and with the II metatarsal bone.

The intermediate sphenoid bone, os cuneiforme intermedium, has articular platforms: on the medial surface - for articulation with the medial sphenoid bone, os cuneiforme mediale, on the lateral side - for articulation with the lateral sphenoid bone, os cuneiforme laterale.

The lateral sphenoid bone, os cuneiforme laterale, also has two articular surfaces: from the medial side for articulation with the intermediate sphenoid bone, os cuneiforme intermedium, and the base of the II metatarsal bone, os metatarsale II, and from the lateral side - with the cuboid bone, os cuboideum.

Cuboid, os cuboideum, is located outwards from the lateral sphenoid bone, in front of the calcaneus and behind the base of the IV and V metatarsal bones.

The upper surface of the bone is rough, on the medial there are articular platforms for articulation with the lateral sphenoid bone, os cuneiforme laterale, and the scaphoid bone, os naviculare. On the lateral edge of the bone there is a downward tuberosity of the cuboid bone, tuberositas ossis cuboidei. Anterior to it, the groove of the tendon of the long peroneal muscle, sulcus tendinis m. peronei longi, which passes to the lower surface of the bone and crosses it obliquely behind and outside, anteriorly and inwardly, according to the course of the tendon of the muscle of the same name.

The posterior surface of the bone has a saddle-shaped articular surface for
Joints with the same articular surface of the calcaneus. The protrusion of the lower medial section of the cuboid bone, bordering the edge of this articular surface, is called the calcaneal process, processus calcaneus. It provides support for the anterior end of the calcaneus.
The anterior surface of the cuboid bone has an articular surface divided by a comb for articulation with IV and V metatarsal bones, os metatarsale IV et os metatarsale V.

Metatarsal bones
The metatarsal bones, ossa metatarsalia, are represented by five (I-V) thin long bones located in front of the tarsus. In each metatarsal bone, a body, corpus, and two epiphysis are distinguished: the proximal - the base, basis, and the distal - the head, caput.
Bones are counted from the side of the medial edge of the foot (from the thumb to the little toe). Of the 5 metatarsal bones, bone I is shorter, but thicker than the rest, bone II is the longest. The bodies of the metatarsal bones are triangular. The upper, dorsal, surface of the body is somewhat convex, the other two are the lower (plantar) surfaces, converge at the bottom, forming a pointed comb.
The bases of the metatarsal bones represent the most massive part of them. They have the shape of a wedge, which, with its expanded part, in the I-IV metatarsal bones, is directed upwards, and in the V metatarsal bone, in the medial direction. The lateral surfaces of the bases have articular platforms through which the adjacent metatarsal bones are articulated with each other.
On the posterior surfaces of the bases, there are articular surfaces for articulation with the bones of the tarsus. On the lower surface of the base of the I metatarsal bone is the tuberosity of the I metatarsal bone, tuberositas ossis metatarsalis primi. Have
V metatarsal bone in the lateral part of the base also has tuberosity
V metatarsal bone, tuberositas ossis metatarsalis quinti, which is well palpable. The front ends, or heads, of the metatarsal bones are compressed from the sides. The peripheral part of the heads has a spherical articular surface articulating with the phalanges of the fingers. On the lower surface of the head of the I metatarsal bone, on the sides, there are two small smooth platforms, to which the sesamoid bones, ossa sesamoidea, of the big toe are adjacent. The head of the I metatarsal bone is well palpable.
In addition to the indicated sesamoid bones in the area of ​​the metatarsophalangeal joint of the thumb, there is one sesamoid bone in the interphalangeal joint of the same toe, as well as non-permanent sesamoid bones in the thickness of the tendon of the long fibular muscle, in the area of ​​the plantar surface of the cuboid bone.
Between the bones of the metatarsus there are 4 interosseous spaces, spatia interossea metatarsi, which are filled with interosseous muscles.