The anatomy of the human leg is a complex system of interconnected muscles, bones and ligaments. The development of the lower leg muscles determines their structure, as is the case with the muscular system of the thigh or pelvic region - all these areas are responsible for the ability to walk upright, and this type of movement implies a high load. The entire muscular complex of the lower leg, intermuscular septa and fascia of the leg (FG) is responsible for the correct functioning of the knees, ankles and feet.

Calf muscles: location, functions

This zone is included in the leg and runs from the knee to the foot. The skeletal foundation of the site is built on only two components - the tibia and fibula. The muscles cover them on 3 sides. Complex functionality:

• implementation of movement;
• flexion/extension of joint mechanisms.

Tibial segment

Classified as part of the anterior calf muscle group. This system controls the area of ​​the skeletal apparatus of the limb in question. The tibialis anterior muscle (TAM) begins to develop on the outer plane of the bone of the same name. Subsequently, it moves further than the lower and upper retinaculum, which extend the fibers, which are enlarged processes of the ankle and foot fascia and develop on the lower leg. The PBM is then attached to the base of the growth of the first metatarsus, as well as to the medial cuneiform bone.

The muscle is easy to feel through the skin, this is especially noticeable in the place where the foot begins, because the connecting tendon of the fiber protrudes outward. It works as an extensor of the lower leg muscles and additionally serves as an instep support.

Extensor digitorum (long)

The DRP is localized on top of the previously mentioned element in the initial segment. Growth starts from the tip of the tibia and the frontal marginal surface of the fibula, from the FG and the interosseous membrane. At the foot level, fiber separation occurs into 5 tendons (T):

• 4 are attached to toes 2 to 5;
• the latter - to the beginning of the 5th metatarsal bone.

The extensor digitorum longus also performs the function of the foot, which is clear from its name. Thanks to the tendon attachment to the outside of the foot, the element also has the ability to pronate.

Extensors of the thumbs

Between the middle of the PBM and the side of the DRP, in some places covered in the anterior region by these muscles, there is a long extensor pollicis. It is formed in the second third of the frontal surface of the fibula and the joints of the lower leg elements. The tendons belonging to the muscle move towards the heel, spreading behind the holders mentioned above in a separate synovial sheath, after which they join the distal phalanx of the big toe as a whole, and optionally to the one next to the nail. The task of the muscle of the anterior surface of the shin is to straighten the ankle joint and ensure the motor ability of the foot area in the ankle.

Flexor digitorum

The flexor digitorum longus (flexor digitorum longus) arises from the dorsum of the tibia and moves toward the sole, sliding behind the medial malleolus in a special channel that lies below the fixator.

Near the plantar surface, the Digitorum longus runs through the tendon that flexes the big toe; the quadratus muscle is attached to it, which subsequently disperses into 4 striated muscles connected to the DF (distal phalanges) from the second to 5th toes.

The element supinates the foot and causes the toes to clench. The task of the quadratus muscle is to balance the impact, which is necessary because... the divided part of the chipboard performs flexion and also balances the limb to the midplane of the body. The attached muscular structure pulls outward, the adductive effect weakens, and flexion occurs rather in the vertical plane of the body.

Triceps surae muscle

Belongs to the muscles of the back of the lower leg. The name is due to its structure, because has three muscle ends (heads):

• the first and second are closer to the dermis and form the calves;
• the third lies deeper in the limbs and makes up the soleus muscle, holding the area on the talus without moving it forward.

The processes connect to form the Achilles tendon, which is attached to the tubercle of the calcaneus.

The medial and lateral condyles of the femoral region are the starting point for calf growth. The second head is less developed than the first, descending a little further. They have two bending tasks:

• in the knee;
• ankle joint.

The soleus head grows from the dorsal part of the upper third of the BB bone and from the tendon between the tibia and fibula of the skeleton. Located behind the subtalar joint and ankle, the fiber regulates the flexion of the medial edge of the foot.

In the superficial visible part, the triceps surae muscle is visually distinguished and can be examined by touch without difficulty. It is characterized by a maximum range of rotation perpendicular to the ankle joint due to the fact that the ligaments on the heel in the rear of the foot stand out behind the mentioned axis.

The diamond-shaped popliteal fossa is formed by the heads of the gastrocnemius muscle. The rhombus is limited by the posterior group of muscles of the lower leg, as well as:

1. The anterosuperior part is the biceps femoris muscle.
2. Back and top – semimembranosus muscle.
3. In the lower part are the plantaris muscle and the ends of the gastrocnemius.
4. The bottom is the capsule of the knee joint and the thigh.

Along the bottom are threads of nerve endings and arteries that feed and control muscle and bone tissue.

Flexor pollicis

The most powerful muscle in the lower leg - hallucis longus - develops from the bottom of the dorsal section of the ankle joint and the dorsal membrane. Near the sole, the muscle lies in the middle of the components of the flexor muscle minor and grows from the beginning of the distal phalanx of the first finger.

The purpose of the existence of the long flexor tendon of the thumb, or first, finger in the body is to compress it and the foot.

Due to partial fusion with the flexor tendon, the position of the second and third fingers is affected. There are 2 sesamoid bones near the metatarsophalangeal joint; thanks to them, the torque of the DSBP increases.

Tibialis posterior muscle

It is localized deeper than the triceps muscle between the flexor muscles of the leg. The beginning is the back side of the interosseous septum and the adjacent parts of the tibia. After passing through the medial malleolus, the muscle attaches to the tubercle of the scaphoid and sphenoid bones, to the metatarsus. The tibialis posterior muscle, which belongs to the adductor muscles of the leg, is responsible for the following actions:

• bringing the foot into motion;
• supination;
• flexion.

The fiber is separated from the soleus muscle by a canal, the so-called. tibial-popliteal, in front appearance resembling a thin slit. In its bed lie nerve fibers and blood vessels.

Second division of tibial fibers

It begins to form in the same place as the muscle described above and is located in a mass of tissue, unlike the triceps muscle. Attached to the metatarsal, sphenoid and navicular bones. This fragment of the lateral group of muscles of the lower leg, together with the CL, bends and moves the foot.

Popliteal segment

Consists of a complex of interconnected small fibers lying near the surface of the knee. They go through:

• from the lateral femoral condyle;
• deeper than the calf area and knee synovial bursa;
• rise above the soleus muscle and are attached to the tibia.

Since the muscle strips are partially attached to the knee bursa, the bursa is pulled back during flexion.

The functional tasks performed by the popliteus muscle include:

• ensuring leg mobility;
• her natural pronation.

Long fibular segment

A distinctive feature of the site is its feathery structure. The muscle lies on top of the MB of the bone, is attached to its 2 thirds from the outer part, growing from:

• its head part;
• partially – fascia;
• condyle LBC.

When the peroneus longus muscle contracts, 3 types of movement are provided at once:

• lead;
• pronation (bending);
• the leg bends at the foot.

The tendon of this fiber wraps around the lateral part of the ankle behind and below. Near the heel they meet the extreme retinaculum. Having moved further and being surrounded by the muscles of the sole, the element spreads along a groove running along the lower surface of the cuboid bone of the foot and ends on its inner side.

Short fibular fibers

It is this subtype of flat muscular formations that raises the lateral edge of the foot, does not allow it to turn with the plantar side inward and clubfoot, and performs plantar flexion.

The short MB fiber is formed by the fusion of the crural septa and the fibula on its superficial side facing the skin. As the tendon moves downward and is released from the peroneus brevis muscle, it fits around the malleolar lateral structure from the dorsal lower edge, after which it is attached to the tuberosity of the last metatarsal bone.

Common malformations

In addition to serious but rare anomalies such as the absence of one of the limbs or some of their parts, fusion together and other global defects, among the pathologies of the formation of bones and muscles of the leg there are:

1. Curvature of the leg in the frontal plane - may go away on its own after the baby learns to walk independently, and no treatment is required.
2. Native subluxation or dislocation is often bilateral; it is accompanied by a change in the shape of the knees and contracture. The type of deformity diagnosed depends on the strength and nature of the changes. The changes are due to the fact that the muscles are not attached in the places where they should, due to the underdevelopment of the femur and shin bones. This pathology may be accompanied by problems with the structure and function of the ankle, insufficient development or complete absence of the tibia.
3. Hypoplasia (underdevelopment and small size) of elements.
4. The presence of false joints, constriction of the ligaments of the feeding nodes.

Even with the correct development of leg structures, abnormalities may appear as they grow, caused by deficient bone mineralization, inflammation in the joints and muscles, excessive or insufficient loads, injuries, improper selection of shoes or poor nutrition.

The lower leg is a complex structure consisting of many finely adjusted components, so this part of the body can be subject to pathological changes. High permanent load increases the risk of developing diseases and defective conditions. It needs to be given attention in general health care, especially in infants in the initial stages of postnatal development and in older people due to the vulnerability of joints and fragility of bone tissue. When eating, it is necessary to maintain the level of beneficial microelements for the human skeleton by periodically taking a complex of vitamins. It is also necessary to monitor the condition of the joints,, if possible, reduce the load on the limbs with the help of specialized orthopedic devices and develop muscles.

Superficial layer (calf muscles):

1. M. triceps surae, triceps surae muscle, forms the main mass of the calf elevation. It consists of two muscles - m. gastrocnemius, located superficially, and m. soleus, lying under it; both muscles below have one common tendon.

M. gastrocnemius, gastrocnemius muscle, starts from the facies poplitea of ​​the femur behind both condyles with two heads, which, with their tendon origin, fuse with the capsule of the knee joint. The heads pass into the tendon, which, merging with the tendon m. soleus, continues into the massive Achilles tendon, tendo calcaneus (Achillis), attached to the posterior surface of the tubercle of the calcaneus.

At the point of attachment between the tendon and the bone there is a very permanent synovial bursa, bursa tendinis calcanei (Achillis).

M. soleus, soleus muscle, thick and meaty. It lies under the calf muscle, occupying a large area on the bones of the lower leg. The line of its origin is located on the head and on the upper third of the posterior surface of the fibula and descends along the tibia almost to the border of the middle third of the tibia with the lower one. In the place where the muscle spreads from the fibula to the tibia, a tendon arch is formed, arcus tendineus m. solei, under which the popliteal artery and n. tibialis. Tendon sprain m. soleus merges with the Achilles tendon.

2. M. plantaris, plantaris muscle. It originates from the facies poplitea above the lateral condyle of the femur and from the capsule of the knee joint, soon passing into a very long and thin tendon that stretches in front of the m. gastrocnemius and attaches to the calcaneal tubercle. This muscle undergoes reduction and in humans is a rudimentary formation, as a result of which it may be absent.

Function. All muscles m. triceps surae (including m. plantaris) produces flexion at the ankle joint both with the free leg and with support on the end of the foot. Since the line of pull of the muscle passes medially to the axis of the subtalar joint, it also causes adduction of the foot and supination. When standing, the triceps surae (especially the m. soleus) prevents the body from tipping forward at the ankle joint.

The muscle has to work primarily when burdened by the weight of the whole body, and therefore it is strong and has a large physiological diameter; m. gastrocnemius, as a biarticular muscle, can also flex the knee when the lower leg and foot are strengthened. (Inn. m. triceps surae and m. plantaris - LV - SII. N. tibialis.)

Deep layer, separated from the superficial by the deep fascia of the leg, is composed of three flexors, which oppose the three extensors lying on the anterior surface of the leg.

3. M. flexor digitorum longus, long flexor of the fingers, the most medial of the deep layer muscles. It lies on the posterior surface of the tibia, from which it originates. The tendon of the muscle descends behind the medial malleolus, in the middle of the sole it is divided into four secondary tendons, which go to the four fingers I-V, pierce the tendon m. flexor digitorum brevis and are attached to the distal phalanges.

Function in terms of finger flexion, it is small; the muscle mainly acts on the foot as a whole, producing flexion and supination when the leg is free. She also, together with m. triceps surae is involved in placing the foot on the toe (walking on tiptoes). When standing, the muscle actively helps strengthen the arch of the foot in the longitudinal direction. When walking, presses fingers to the ground. (Inn. LV - SI. N. tibialis.)

4. M. tibialis posterior, posterior tibialis muscle, occupies the space between the bones of the leg, lying on the interosseous membrane and partly on the tibia and fibula. From these places the muscle receives its initial fibers, then with its tendon it bends around the medial malleolus and, reaching the sole, is attached to the tuberositas ossis navicularis, and then by several bundles to the three wedge-shaped bones and the bases of the II-IV metatarsal bones.

Function. Bends the foot and brings it together with m. tibialis anterior. Together with other muscles also attached to the medial edge of the foot (m. tibialis anterior et m. peroneus longus), m. tibialis posterior forms a kind of stirrup, which strengthens the arch of the foot; stretching its tendon through the lig. calcaneonavicular, the muscle supports the head of the talus together with this ligament. (Inn. LV - SI. N. tibialis.)

5. M. flexor hallucis longus, long flexor of the big toe, the most lateral of the deep layer muscles. Lies on the posterior surface of the fibula, from which it originates; the tendon runs in a groove on the processus posterior of the talus, approaches under the sustentaculum tali to the big toe, where it attaches to its distal phalanx.

Function. Flexes the thumb, and also due to a possible connection with the tendon of the m. flexor digitorum longus can act in the same sense on fingers II and even III and IV. Like the rest of the posterior muscles of the leg, m. flexor hallucis longus produces flexion, adduction and supination of the foot and strengthens the arch of the foot in the anteroposterior! direction. (Inn. N. tibialis.)

Anatomy of the lower leg

Shin bones

The shin has a fairly simple structure. This part of the leg consists of two bones of different sizes, which are called the tibia and fibula. The tibia of the lower leg connects to the femur at the knee joint and is the second largest bone in the human leg.

The tibia connects to the fibula below the knee joint.

The foot has a much more complex structure. It consists of more than twenty-six bones and thirty-three joints. The structure of the foot is in many ways similar to the structure of the hands, but the foot serves to bear much more weight. Therefore, her muscles and bones are stronger, but less mobile.

1 - Tibia; 2 - Fibula; 3 - Foot bones

Calf muscles

The lower leg contains approximately 20 muscles. They are responsible for raising and lowering the leg and moving the toes. A sufficient number of muscles that move the legs begin at the back of the knee and end at the foot.

The lower leg contains three muscle groups: the anterior (muscles responsible for extending the feet and toes), the outer (the peroneal muscle group, responsible for moving the outer edge of the foot) and the posterior (the muscles responsible for flexing the feet and toes).

The calf muscle is among others the most powerful. It begins at the heel bone of the foot, attaching to it through the Achilles (heel) tendon.

On the back of the lower leg are the calves, consisting of two muscles: the gastrocnemius (a large muscle that forms bulges visible under the skin) - it is formed by two parts or heads, due to which its diamond-shaped shape is achieved, and the soleus - a type of flat muscle located under the gastrocnemius .

1 - Peroneus longus muscle; 2 - Extensor digitorum longus; 3 - Peroneus brevis muscle; 4 - Tendon of the long extensor pollicis; 5 - Tibia; 6 - Tibialis anterior muscle; 7 - Superior retinaculum of the extensor tendons; 8 - Inferior extensor retinaculum

1 - Inner head of the gastrocnemius muscle; 2 - Heel (Achilles) tendon; 3 - Plantaris muscle; 4 - External head of the gastrocnemius muscle; 5 - Soleus muscle

When a person walks, runs or jumps, the calf muscle creates tension on the heel, and this helps move forward.

The Achilles tendon is considered one of the most important parts of the lower leg. With its help, three muscles are attached to the heel bone at once: the plantar, gastrocnemius and soleus.

The Achilles tendon allows a person to run, jump and engage in other physical activities.

Vessels and innervation of the leg

The lower leg is supplied with blood through the tibial arteries: posterior and anterior, which begin in the popliteal artery. Veins of the same name run along the corresponding arteries and end in the popliteal vein.

The lower leg is innervated by the tibial and peroneal nerves.

Arteries and veins of the leg:
1 - Popliteal artery; 2 - Medial head of the gastrocnemius muscle; 3 - Tendinous arch of the soleus muscle; 4 - Posterior tibial artery; 5 - Flexor digitorum longus; 6 - Tibialis posterior muscle; 7 - Deep peroneal nerve; 8 - Lateral head of the gastrocnemius muscle; 9 - Soleus muscle; 10 - Tibial nerve; 11 - Peroneal artery; 12 - Flexor hallucis longus; 13 - Heel (or Achilles) tendon

1 - Peroneus longus muscle; 2 - Common peroneal nerve; 3 - Superficial peroneal nerve; 4 - Peroneus brevis muscle; 5 - Cutaneous branches of the superficial peroneal nerve; 6 - Sural nerve; 7 - Fascia of the leg; 8 - Anterior tibial vein; 9 - Tibialis anterior muscle; 10 - Tibial artery; 11 - Deep peroneal nerve; 12 - Extensor digitorum longus; 13 - Long extensor of the big toe; 14 - Neurovascular bundle in the lower leg

1 - Fibula; 2 - Soleus muscle; 3 - Tibia; 4 - Plantaris tendon; 5 - Medial head of the gastrocnemius muscle; 6 - Small saphenous vein of the leg

Among the muscles of the lower leg, there are anterior, lateral and posterior muscle groups. The anterior group includes mainly the extensors of the foot, the lateral group includes the flexors and pronators of the foot, and the posterior group includes the flexors and supinators of the foot.

Rice. 135. Muscles of the lower leg (front view):

1 - peroneus longus muscle; 2 - medial head of the gastrocnemius muscle; 3 - anterior tibial muscle; 4 - soleus muscle; 5 - short peroneus muscle; 6 - extensor digitorum longus; 7 - upper extensor retinaculum; 8 - tendon of the anterior tibialis muscle; 9 - lower extensor retinaculum

Front group

The anterior tibialis muscle (m. tibialis anterior) (Fig. 90, 135, 142, 146) extends and adducts the foot, raising its medial edge. A long, narrow, superficial muscle whose origin is located on the lateral condyle of the tibia and the interosseous membrane. The attachment site is located on the plantar surface of the medial sphenoid bone and on the base of the first metatarsal bone. The subtendinous bursa of the tibialis anterior muscle is also located here (bursa subtendinea m. tibialis anterioris).

The long extensor digitorum (m. extensor digitorum longus) (Fig. 90, 135, 141, 142, 146) extends the II–V fingers, as well as the foot, lifting its lateral (outer) edge together with the third peroneal muscle. The muscle begins from the upper epiphysis of the tibia, the head and anterior edge of the fibula and the interosseous membrane. The muscle passes into a long, narrow tendon, which divides into five thin individual tendons. Four of them are attached to the back of the II–IV fingers in such a way that the middle bundles of tendons are attached to the base of the middle phalanx, and the lateral bundles to the base of the distal phalanx. The fifth tendon attaches to the base of the fifth metatarsal bone.

The long extensor hallucis longus (Fig. 136) extends the big toe, as well as the foot itself, raising its medial edge. Partially covered by the two previous muscles, located between them. Its point of origin is the lower part of the medial surface of the body of the fibula, and the point of attachment is the base of the distal phalanx. Part of the tendon bundles fuses with the base of the proximal phalanx.

Lateral group

The long peroneus muscle (m. peroneus longus) (Fig. 135, 137, 138, 139, 144, 146) abducts and flexes the foot, lowering its medial edge. Located on the lateral surface of the lower leg. The muscle begins from the head and upper part of the body of the fibula and is attached to the medial sphenoid bone and the base of the I–II metatarsal bones.

The short peroneus muscle (m. peroneus brevis) (Fig. 135, 136, 138, 139, 140) abducts and flexes the foot, raising its lateral edge. This long and thin muscle is located on the outer surface of the fibula. It is covered by the peroneus longus muscle. Its point of origin is located on the lower half of the lateral surface of the body of the fibula and the intermuscular septum. The attachment point is the tuberosity of the fifth metatarsal bone.

Back group

The posterior group includes two muscle groups.

Surface layer

The triceps surae muscle (m. triceps surae) flexes the lower leg at the knee joint, flexes and rotates the foot outward. When the foot is in a fixed position, the lower leg and thigh are pulled posteriorly. The muscle consists of the superficial gastrocnemius muscle and the deep soleus muscle. The gastrocnemius muscle (m. gastrocnemius) (Fig. 90, 132, 133, 134, 135, 137, 138, 146) has two heads. The medial head (caput mediale) starts from the medial epicondyle of the femur, and the lateral head (caput laterale) starts from the lateral epicondyle. Both heads are connected into a common tendon and attached to the calcaneal tubercle. The soleus muscle (m. soleus) (Fig. 90, 135, 137, 138, 139, 146) is covered by the gastrocnemius muscle, starts from the head and upper third of the posterior surface of the body of the fibula and from the line of the soleus muscle of the tibia. The muscle is attached to the calcaneal tubercle, fused with the tendon of the gastrocnemius muscle. The common tendon in the lower third of the leg forms the heel tendon (tendo calcaneus) (Fig. 137, 138), the so-called Achilles tendon. The mucous bursa of the heel tendon (bursa tendinis calcanei) is also located here.

The plantaris muscle (m. plantaris) (Fig. 134, 137, 138) stretches the capsule of the knee joint when flexing and rotating the tibia. The muscle is rudimentary and unstable, has a spindle-shaped shape. Its point of origin is located on the lateral condyle of the femur and the bursa of the knee joint, and its attachment point is on the calcaneus.

Rice. 136. Muscles of the leg and foot (front view):

1 - articular muscle of the knee; 2 - quadratus femoris muscle; 3 - short peroneus muscle; 4 - long extensor of the big toe; 5 - short extensor of the big toe; 6 - tendon of the long extensor of the big toe; 7 - extensor digitorum brevis

Rice. 137. Muscles of the lower leg (back view):

1 - plantaris muscle; 2 - gastrocnemius muscle: a) medial head, b) lateral head; 3 - soleus muscle; 4 - fascia of the leg; 5 - tendon of the posterior tibial muscle; 7 - flexor digitorum longus tendon; 8 - calcaneal tendon (Achilles tendon)

Rice. 138. Muscles of the lower leg (back view):

1 - plantaris muscle; 2 - popliteal muscle; 3 - soleus muscle; 4 - tendon of the plantaris muscle; 5 - gastrocnemius muscle: a) medial head, b) lateral head; 6 - tendon of the long peroneus muscle; 7 - tendon of the posterior tibial muscle; 8 - short peroneus muscle; 9 - flexor digitorum longus tendon; 10 - calcaneal tendon (Achilles tendon)

Rice. 139. Muscles of the lower leg (back view):

1 - popliteus muscle; 2 - soleus muscle; 4 - peroneus longus muscle; 5 - flexor digitorum longus; 6 - flexor pollicis longus; 7 - short peroneus muscle; 8 - flexor retinaculum; 9 - superior retinaculum of the peroneus longus and brevis muscles

Rice. 140. Muscles of the leg and foot (back view):

1 - popliteus muscle; 2 - short peroneus muscle; 3 - tibialis posterior muscle; 4 - short flexor of the big toe; 5 - short flexor of the little toe; 6 - flexor digitorum longus tendon; 7 - interosseous muscles

Deep layer

The popliteus muscle (m. popliteus) (Fig. 138, 139, 140) flexes the lower leg, rotating it inward and retracting the capsule of the knee joint. A short flat muscle, located on the posterior surface of the knee joint capsule, starts from it and from the lateral condyle of the femur, and is attached to the posterior surface of the body of the tibia.

The long flexor of the fingers (m. flexor digitorum longus) (Fig. 90, 137, 138, 139, 140, 143, 146) bends the distal phalanges of the II–V fingers and takes part in the outward rotation of the foot, raising its medial edge. It is located on the posterior surface of the tibia, starting from the middle third of the posterior surface of the body of the tibia and from the deep sheet of the fascia of the leg. The muscle tendon is divided into four tendons, which are attached to the base of the distal phalanges of the II–V fingers.

The long flexor of the thumb (m. flexor hallucis longus) (Fig. 139, 143, 146) flexes the thumb, takes part in the flexion of fingers II–V thanks to fibrous bundles, which are a continuation of the tendon, and also flexes and rotates the foot. The muscle starts from the lower two-thirds of the posterior surface of the body of the fibula and from the interosseous membrane, and is attached to the base of the distal phalanx of the thumb.

The tibialis posterior muscle (m. tibialis posterior) (Fig. 137, 138, 139, 140, 146) flexes and adducts the foot, rotating it outward. It is located on the interosseous membrane between the two previous muscles and is partially covered by the flexor pollicis longus. Its point of origin is on the posterior surfaces of the bodies of the tibia and fibula, and its attachment point is on the wedge-shaped bones of the foot and the tuberosity of the navicular bone.

The lower leg muscles form three groups - anterior, posterior and lateral. (see Fig. 157, 158; Fig. 161).

Anterior calf muscle group

The anterior group of leg muscles, which are extensors in function, includes three muscles: the tibialis anterior muscle, the extensor digitorum longus muscle and the extensor pollicis longus muscle. The anterior calf muscles, located in the front of the lower leg, attach to the bones of the foot, in particular to the phalanges (digit extensors). These muscles are laterally separated from the lateral group of muscles of the lower leg by the anterior intermuscular septum of the lower leg. The medial muscles of the anterior group are adjacent to the lateral surface of the tibia, and at the back - to the interosseous membrane of the leg.

Tibialis anterior muscle (t. Tibialis anterior) long, tapering downward, located superficially and centrally.

Start: from the lateral process and the upper half of the lateral surface of the body of the tibia, as well as from the upper part of the interosseous membrane and fascia of the leg.

The muscle is directed from top to bottom, bordering on the side with the long extensor muscle of the fingers (at the top) and with the long extensor muscle of the thumb (in the lower parts of the leg). At the level of the lower third of the leg, the belly of the anterior tibialis muscle passes into a long, thin and flat tendon, passing in the synovial sheath in front of the ankle joint under the upper and lower holders of the extensor muscle and the b.

Attachment: Having rounded the middle edge of the foot, the muscle tendon is attached to the hyposuture surface of the middle wedge-shaped bone and the base of the metatarsal bone. Under the tendon at the place of its attachment is located tendon bursa of the tibialis anterior muscle (bursa subtendinea musculi tibialis anterioris).

Function: extends the foot at the ankle joint and distracts it (supinate), raises the middle edge of the foot and rotates the foot outward, strengthens the longitudinal arches of the foot. With a fixed foot, the lower leg tilts forward, helping to maintain the body in an upright position.

Blood supply:

Innervation:

Extensor digitorum longus muscle(t. Extensor digitorum longus) is a flat, unipennate muscle located lateral to the tibialis anterior muscle.

Start: from the lateral process of the tibia, the head and anterior edge of the fibula, as well as from the upper third of the interosseous membrane, the anterior intermuscular septum and the fascia of the leg.

The muscle is directed downwards, its tendon passes under the upper and lower holders of the extensor muscles. At the level of the ankle joint, the muscle tendon divides into four tendons located in the common synovial sheath under the extensor muscle holders.

Rice. 161. Deep muscles of the right leg and foot. A- front view, B- back view

Attachment: each tendon at the level of the proximal phalanges of the II-V fingers is divided into three tendon bundles. The middle bundle is attached to the base of the middle phalanx, and the two lateral bundles are attached to the base of the terminal phalanx. The inconstant fifth tendon of this muscle is attached to the base of the fifth metatarsal bone.

This tendon often fuses with the inconstant third peroneal muscle, i.e. Fibularis (peroneus) tertius, which begins from the lower third of the fibula and interosseous membrane of the leg, and attached to the base of the fifth metatarsal bone.

Function: extends the II-V fingers in the midphalangeal and metatarsophalangeal joints, extends the foot at the ankle joint, raises its lateral edge and slightly adducts the foot. Tilts the shin with a fixed foot. The third peroneal muscle raises the lateral edge of the foot.

Blood supply: anterior tibial artery.

Innervation: deep peroneal nerve (L4-S1).

Extensor pollicis longus muscle (t. Extensor hallucis longus) flat and single-pinnate. The cilium is located between the tibialis anterior muscle (anteriorly) and the extensor digitorum longus muscle (laterally), which partially covers this muscle in front.

Start: from the middle third of the anterior surface of the fibula and the interosseous membrane of the leg. Next, the muscle is directed from top to bottom, passes into a tendon, which passes to the dorsum of the foot under the upper and lower holders of the extensor muscles in a separate synovial sheath.

Attachment: on the dorsum of the foot, the tendon of the long extensor muscle of the big toe is located medially (palpated under the skin) and is attached to the base of the terminal phalanx of the big toe. Individual tendon bundles of the muscle can also attach to the base of the proximal phalanx. Between the tendon and the head and metatarsal bone is located bursa musculi extensoris hallucis longi.

Function: extends the big toe at the midphalangonal and metatarsal-phalangeal joints, straightens the foot at the ankle joint, and raises its middle edge. If the foot is fixed, the lower leg tilts forward.

Blood supply: anterior tibial artery.

Innervation: deep peroneal nerve (L2-S1).

Posterior calf muscle group

The muscles of the posterior group of the lower leg, located in its posterior section, consist of two parts - superficial (gastrocnemius) and deep, which are separated by a sheet of fascia (see Fig. 128). In the superficial part lies the powerful triceps calf muscle and plantaris muscle. The deep part contains the popliteus, flexor digitorum longus, flexor pollicis longus, and tibialis posterior muscles.

Superficial (gastrocnemius) part of the posterior muscle group of the lower leg

Triceps calf muscle(t. Triceps surae) forms the convex roundness of the posterior part of the leg - the calf, it consists of two separate muscles. Superficially located is the gastrocnemius muscle, and deeper is the soleus-like muscle. The gastrocnemius muscle extends over the knee and ankle joints, and the soleus muscle extends only through the supracalcaneal and ankle joints. Both muscles share a thick calcaneal tendon ( Achilles tendon), which is attached to the calcaneus.

Calf muscle (t. Gastrocnemius) flat and wide, has two massive heads: squat and lateral, which border the popliteal fossa from below.

Beginning: lateral head (caput laterale) starts from the popliteal surface of the femur above its lateral condyle, and with an average head (caput mediale) also starts from the popliteal surface of the femur, but above the medial condyle.

Approximately in the middle of the lower leg, both heads join into a common abdomen, a little lower it turns into a wide flat tendon, gradually narrowing. Between each head of the gastrocnemius muscle and the capsule of the knee joint (at the level of the posterior surface of the corresponding process of the femur) is a synovial bursa: lateral And medial tendon and bursa of the gastrocnemius muscle (bursa subtendinea musculi gastrocnemii lateralis et bursa subtendinea musculi gastrocnemii medialis). Both bursae are often combined with the knee joint cavity.

soleus muscle (t. Soleus)- This is a thick and thin double-pinnate muscle with a powerful abdomen. The shape of the muscle corresponds to its name. Located in front of the calf muscle.

Start: from the head and posterior surface of the upper third of the fibula, the line of the soleus muscle, runs obliquely on the posterior surface of the upper third of the body of the tibia, and also from tendon arch Flounder-shaped knuckles (arcus tendines musculi solei), which is stretched obliquely between the fibula and tibia. The muscle goes down, passes into the flat tendon, connecting to the tendon of the gastrocnemius muscle

Attachment: the gastrocnemius and soleus muscles form one thick calcaneal tendon (tendo calcaneus) - Achilles tendon, which is attached to the calcaneal tubercle. Lies between the calcaneal tendon and the calcaneus calcaneal tendon bursa (bursa tendinis calcanei).

Function: bends the foot at the ankle joint, slightly adducts it and rotates it outward, promotes flexion of the lower leg at the knee joint, and raises the heel in a vertical position. If the foot is fixed, pull the shin and thigh back.

Blood supply:

Innervation: tibial nerve (L4-S2).

Plantaris muscle (t. Plantaris) unstable, has a small muscle belly of the fusiform (| crowd 3-7 cm long and a thin long tendon. The belly is located on the posterior surface of the upper third of the leg in front of the gastrocnemius muscle, and the soft muscle tendon runs down between the gastrocnemius and soleus muscles, near the medial edge of the calcaneal tendon .

Start: from the posterior surface of the lateral supra- lobe of the femur slightly above the beginning of the lateral head of the gastrocnemius muscle, as well as from the capsule of the knee joint.

Attachment: the thin tendon of the plantaris muscle predominantly fuses with the calcaneal tendon, sometimes independently attaching to the calcaneal tubercle.

Function: participates in flexion of the foot, stretches the capsule of the knee joint.

Blood supply: popliteal artery.

Innervation: tibial nerve (L4-S2).

Deep part of the posterior calf muscle group

Popliteus muscle (t. Popliteus) flat and short, lies in the popliteal fossa directly on the posterior surface of the knee joint capsule (see Fig. 158).

Start: a strong thick tendon from the lateral surface of the lateral process of the femur below the insertion of the bypass peroneal ligament and from the capsule of the knee joint.

Attachment: the muscle is directed downward and medially, slightly expanding, and is attached to the posterior surface of the tibia above the line of the soleus muscles.

Function: bends the lower leg, rotates it inward, stretches the capsule of the knee joint. Blood supply: popliteal artery.

Innervation: tibial nerve (L4-S2). Flexor digitorum longus muscle (τη. Flexor digitotvm longus) dvoperistny and has a fusiform shape, located on the posterior surface of the tibia behind and medially to the posterior tibial muscle.

Start: from the posterior surface of the body of the tibia below the line of the soleus muscles, the deep plate of the fascia of the leg and the posterior intermuscular septum of the leg.

The muscle is directed from top to bottom, its long strong tendon goes around the back and bottom of the squat bone and support of the supracalcaneal bone, passing to the sole in a separate synovial sheath under the flexor muscle holder. At this location, the flexor digitorum longus tendon is located between the tendons of the tibialis posterior (anteriorly) and the flexor pollicis longus tendon (lateral).

Attachment: On the plantar surface, the flexor digitorum longus tendon is located between the flexor digitorum brevis muscle (bottom) and the flexor pollicis longus tendon (top). The tendon is divided into four independent tendons, each of which passes between the two legs of the tendon of the short flexor muscle of the fingers and is attached to the plantar surface of the terminal phalanx of the II-V fingers. In the area of ​​the toes, the tendons pass through the synovial sheaths of the toes.

Function: bends the II-V fingers at the interphalangeal and metatarsal-phalangeal joints, flexes the foot at the ankle joint, rotates it outward, and helps strengthen the arches of the foot.

Blood supply: posterior tibial artery. Innervation: tibial nerve (L4-S2).

Flexor pollicis longus muscle (t. Flexor hallucis longus) is the largest of the deep muscles of the lower leg, has a double structure. Located laterally, partially covering behind the tibialis posterior muscle. In the middle and lower parts of the lower leg it borders on the lateral edge of the long flexor digitorum muscle. The flexor pollicis longus muscle is separated from the lateral group of muscles of the leg by the posterior intermuscular septum of the leg.

Start: from the posterior surface of the lower two-thirds of the body of the fibula, the interosseous membrane and the posterior intermuscular septum of the leg.

At the level of the lower third of the leg, the muscle continues into a long tendon, which bends around the posterior and inferior bones, passing in a separate synovial sheath on the side of the tendon of the long flexor digitorum muscle under the holder of the flexor muscles. The tendon of the flexor pollicis longus muscle runs forward in the groove of the same name on the posterior process of the supracalcaneal bone and further under the support of the supraccaneal bone. On the plantar surface, this tendon is located between the flexor digitorum longus tendon (bottom) and the bony base of the foot (top).

Attachment: The tendon of the flexor pollicis longus muscle, passing on the sole between the medial and lateral heads of the short flexor pollicis muscle, is attached to the plantar surface of the terminal phalanx of the thumb.

Function: flexes the big toe at the interphalangeal and metatarsophalangeal joints, flexes the foot at the ankle joint, and also adducts and distracts it (supinae), strengthens the longitudinal arch of the foot.

Blood supply: posterior tibial and peroneal arteries.

Innervation: tibial nerve (L4-S2).

Posterior tibialis muscle (t. Tibialis posterior) located deep in the posterior part of the leg, directly on the interosseous membrane of the leg, between the long flexor muscle of the fingers (in the middle) and the long flexor muscle of the thumb (lateral) and covered by these muscles. The upper part of this muscle is dvomerista, the lower part is unihyerista.

Start: from the lower surface of the lateral process and the upper two-thirds of the body of the tibia, as well as from the posterior surface of the body of the fibula and the interosseous membrane of the tibia.

The muscle is directed from top to bottom and above the medial malleolus passes into a powerful tendon, which is located in a separate synovial sheath under the holder of the muscle-spring in the groove on the posterior surface of the medial malleolus. At this point, the tendon passes in front of the tendon of the flexor digitorum longus muscle and then continues on the plantar surface of the foot.

Attachment: to the tuberosity of the scaphoid, as well as in separate bundles to the plantar surface of the three wedge-shaped bones, the bases of the II-IV metatarsal bones and the long plantar ligament.

Function: flexes the foot at the ankle joint, adducts and distracts the (supine) foot, tensions the long plantar ligament, strengthens the longitudinal arches of the foot.

Blood supply: posterior tibial artery.

Innervation: tibial nerve (L4-S2).

Lateral calf muscle group

The lateral muscle group of the leg includes two muscles: the long and short peroneus muscles, which are located in the lateral part of the leg between the anterior and posterior intermuscular septa of the leg under the plate of its own fascia. Both muscles lie in a separate lateral fascial bed.

Peroneus longus muscle [T. fibularis (peroneus) longus] - The CS is a flat, long dupperate muscle, located superficially in the lateral part of the leg (see Fig. 127). From above, the muscle is located directly on the fibula, and from below it covers the short peroneus muscle. The peroneus longus muscle with its anterior edge is adjacent to the long extensor digitorum myasa, and its posterior edge is adjacent to the soleus muscles, separated from them by the anterior and posterior intermuscular septa of the leg.

Start: the muscle begins with two heads - anterior and posterior: the anterior head begins from the head of the fibula, the lateral surface of the lateral process of the tibia and the fascia of the tibia, the posterior head - from the upper part of the lateral surface of the fibula. There remains a narrow gap between these heads - superior musculofibular canal.

The muscle belly in the lower third of the leg passes into a long tendon, which bends around the back of the lateral bone and is directed to the sole, first in the common synovial sheath with the tendon of the peroneus brevis muscle under the upper holder of the peroneus muscles, and then under the lower holder of the peroneus soft muscles in the groove of the tendon of the peroneus longus muscle on the heel bone. On the sole, the tendon of the peroneus longus muscle, located in its own synovial sheath, passes obliquely forward and gyris-medially in the groove of the same name on the lower surface of the cuboid bone.

Attachment: to the plantar surface of the bases of the first and second metatarsal bones and the iris-sphenoid bone.

In the area behind the lateral bone and cuboid bone, the direction of the tendon changes; in its thickness there is fibrocartilage and sesamoid bone.

Function: bends the foot at the ankle joint, lowers the middle edge of the foot, and raises its lateral edge, simultaneously abducting and attracting the foot (pronation), strengthens the transverse and longitudinal arches of the foot.

Blood supply: peroneal and lateral inferior genicular arteries.

Innervation:

Peroneus brevis muscle (t. Fibularis (peroneus) brevis] flat and double-pinnate, located on the fibula and covered by the peroneus longus muscle.

Start: from the lower two-thirds of the lateral surface of the fibula to the lateral bone, as well as from the anterior and posterior intermuscular septa of the leg.

The tendon of the muscle goes around the lateral bone behind, passes down and forward along the lateral surface of the calcaneus under its fibular block in the common synovial sheath with the tendon of the long peroneal muscle (in front of it) under the upper and lower holders of the peroneal muscles.

Attachment: to the tuberosity of the fifth metatarsal bone.

Function: bends the foot at the ankle joint and raises its lateral edge, simultaneously abducting and retracting the foot.

Blood supply: peroneal artery.

Innervation: superficial peroneal nerve (L4-S1).