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We will not describe the metatarsophalangeal and interphalangeal joints here, because they are identical to the joints of the fingers of the hand, with the exception of some functional differences. So, in the metacarpophalangeal joints, the amplitude of flexion is greater than the extension, and in the metatarsophalangeal joints, on the contrary, the extension exceeds the flexion:

• the amplitude of active extension in the metatarsophalangeal joints ranges from 50° to 60°, and flexion is only 30–40°;
• the amplitude of passive extension (Fig. 72), which plays a significant role in the last phase of the step, reaches 90 ° and may even exceed this figure, while passive flexion remains within 45-50 °.

Lateral movements of the toesoccur in the metatarsophalangeal joints within much smaller limits than the corresponding movements of the fingers. The big toe of the human foot, as opposed to thumb monkeys, lost the function of opposition as a result of the transition to movement on two legs.

Active toe extensionIt is provided by three muscles: two external ones - the long extensor of the thumb and the long extensor of the fingers - and one internal muscle of the foot - the short extensor of the fingers.

Short finger extensor(Fig. 73) is located completely on the back of the foot. It originates from the calcaneal floor of the tarsal sinus and from the trunk of the lower retinaculum of the extensor tendons, divides into four fleshy bellies, which are attached by tendons to the outer sides of the corresponding tendons of the long extensor of the fingers, with the exception of the tendon belonging to the first metatarsal bone, which is attached directly to dorsal surface of the first phalanx of the thumb; the fifth finger does not receive any tendon from this muscle at all. Thus, the short extensor of the toes is the extensor of the metatarsophalangeal joints of the first four fingers (Fig. 74).

Long extensor toes and extensor thumb longuslocated in the anterior case of the lower leg, their tendons end at the phalanges.

extensor toe longus tendon(Fig. 75) passes anterior to the ankle joint, deeper than the outer half of the upper retinaculum of the extensor tendons, then posterior to the trunk of the lower retinaculum, after which it is divided into four tendons going to the II-V fingers, passing under the lower plate of the anterior annular ligament. Therefore, the V finger is unbent only due to the action of the common long extensor. This muscle, as its name implies, is an extensor of the toes, but in addition, it serves, very importantly, as a flexor of the ankle joint. Its extensor action on the fingers is only seen in its purest form when its function as an ankle flexor is balanced by an antagonist extensor (mainly the triceps, shown as a white arrow). The tendon of the long extensor of the first finger (Fig. 76) passes deeper than the upper retinaculum of the tendons of the extensor muscles and then penetrates both legs of the lower retinaculum. It is attached to the back surface of both phalanges of the thumb: along the edges of the rear of the first phalanx and to the back surface of the base of the distal phalanx. Therefore, this muscle is not only the extensor of the thumb, but also, no less important, the flexor of the ankle joint. As with the extensor digitorum longus, its thumb extension action only occurs after its function as an ankle flexor is balanced by its antagonist. Duchenne de Boulogne states that the extensor digitorum brevis is the only true extensor.


"Lower limb. Functional anatomy"
A.I. Kapanji

Injury to extensor hallucis longus within the terminal phalanx. This damage does not differ from similar damage to the extensor of the remaining fingers. In the presence of damage localized proximal to the main joint, there are conditions for applying a primary tendon suture, however, after 3-4 weeks, a secondary tendon suture is not feasible due to the reduction of the ends of the tendon.

To fix a defect free tendon graft required or better to apply tendon transposition. During transposition, the tendon of the common extensor of the second finger is used, to which the distal end of the extensor tendon of the thumb is sutured.

extensor longus tear occurs quite frequently. This damage is divided into the following types:
1. direct or indirect rupture caused by trauma;
2. spontaneous rupture:
a) professional hazards,
b) tendon changes,
c) rupture due to damage to the limb.

tendon rupture due to direct trauma and the result of his treatment by tendon transposition are shown in the figure (own observation).

"Spontaneous" tendon ruptures due to occupational hazards, were described at the end of the last century by military doctors (Zander). The left hand of the army drummers, when holding the drumstick, was in a position of pronounced dorsiflexion, due to its unnatural position, tendovaginitis developed, degeneration of the tendons, which led to a "spontaneous" rupture.

A hand injury as a result of a fall of a log in a 47-year-old bricklayer, there is no active extension of the thumb of the right hand (a).
Immediately after the injury, only the skin was sutured. Transposition of the tendon of the own extensor of the index finger was performed in conditions of scar tissue. The result of the intervention is shown in photo b.

Wurtenau described 59 cases of rupture tendons the drummers of the Prussian army. These typical breaks are known in the literature as "drummer's palsy" ("Trommerlahmung" or "Drummer's palsy").

AT Literature describes tendon ruptures due to various diseases. Thus, ruptures due to suppuration, gout, syphilis, tuberculous tendovaginitis (10 cases of Mezon), gonorrhea (Melchior), polyarthritis (Lederich, Herris) and rheumatism (Wadstein).

At post-traumatic tendon rupture from the moment of injury to tendon rupture, there is a latent period lasting from several days to several years. Linder (1885) and Geinicke (1913) first drew attention to the rupture of the tendon of the long extensor of the thumb after a fracture of the radius. Mek Master in 1932 collected a total of 27 such cases from the literature.

F. Steppelmore in 1940 he wrote a generalizing report on 148 cases already known. In 1955, G. Strendell, including his own 14 observations, reports 60 new cases of these injuries. Thus, 208 cases of post-traumatic tendon rupture are known in the literature. This type of injury prevails in women in 67-37%. In most cases, ruptures occur with a dislocation or fracture of the radius without displacement of the fragments. The frequency of rupture of the tendon of the long extensor of the thumb, according to different authors, is different.

The frequency of this complications after fracture of the beam according to Gauk 6:100, according to Moore 3:500, according to Steppelmore 3:1000, according to Markus 4:2134, according to Böhler 1:500.

Long extensor thumb begins on the dorso-radial surface of the middle third of the ulna and on the interosseous membrane. Its tendon at the level of the wrist passes in a separate tendon sheath. This space, the third dorsal tendon sheath, is essentially a canal to the bone. It is deeper and narrower than the other extensor sheaths. The tendon runs obliquely and, intersecting with the long and short radial extensors of the hand, forms the ulnar edge of the "anatomist's snuffbox".

extensor tendon within the proximal phalanx of the thumb, it expands and attaches to the base of the distal phalanx. The main function of the long extensor of the thumb is to extend it at the terminal, main and saddle joints. In addition, this muscle contributes to the retroposition of the thumb, is involved in dorsiflexion of the hand and, together with the adductor muscle of the thumb, in bringing the latter. Its most important function is to fix the saddle joint.

In view of the fact that the condition for good capture is fixation muscles of the centrally lying joints, the loss of the function of the long extensor of the thumb leads to an almost complete loss of the function of gripping the thumb.

overwhelming most post-traumatic tears, a long time after the moment of injury, occurs not as a result of unusual efforts, but in the process of habitual daily movements. Tendon rupture in these cases is not accompanied by pain. After a rupture, the thumb hangs down, the distal phalanx assumes a bent position and cannot be actively extended. Retroposition and adduction of the thumb may not be feasible. The contours of the ulnar edge of the "anatomical snuffbox" are smoothed out.

In view of the lack stabilization of the saddle joint the grip is not strong enough, so the patient is unable to use scissors, write, or button up.

Usually gap localized at the level of the distal edge of the dorsal transverse carpal ligament. Above this level, rupture is rare, occurring in about 7% of cases. The distal end of the tendon is felt over the first metacarpal bone in the form of a knot. The proximal end of the tendon contracts and moves quite far in the central direction. The tendon sheath collapses.

In a relationship pathogenesis of long extensor tendon rupture thumb, the opinions of the authors agree. Emphasis is placed on the special role of the canal and the course of the tendon. Levy and Cohen consider Lister's tubercle, which forms the radial edge of the canal, as a hypomochlion, over which the tendon elongates and deflates during movement.

The value of fractures of the radius for subcutaneous rupture of the extensor thumb has been studied by many authors. According to most researchers, the callus formed after a fracture of the radius narrows the tendon canal, and the existing bone fragments, gradually damaging the tendon, can contribute to its rupture.

According to Rau and Weigel, in tendon rupture, worsening of tendon vascularization at the age of over 25-30 years is of decisive importance, since in adults there are no longitudinal intratendinous vessels, and the external vasculature may suffer from different kind injuries. Strendell believes that the occurrence of a post-traumatic rupture of the tendon is associated with a violation of its blood supply due to trauma (hematoma, thrombosis, degenerative changes in the connective tissue), and the rupture occurs at the point of least resistance, that is, within the vagina.
Complete transection of the tendon with a sharp bone fragment is considered only in rare cases.

Treatment of post-traumatic rupture of the tendon of the long extensor of the thumb must always be operational. According to their principle, operations are divided into two groups, namely: methods of direct connection of the ends of the tendon and methods of tendon transposition - connection of the distal end of the torn tendon with another adjacent extensor tendon.

Method of direct joints of tendon ends, due to stump reduction and tendon degeneration, is now rarely used. Methods for replacing tendon defects also did not lead to satisfactory results (free tendon grafting, replacement of the defect with fascia or artificial material, etc.).

Currently dominated tendon transposition method. This method was first applied by Duplay (1876). He attached the distal end of the long extensor of the thumb to the long radial extensor of the hand. The extensor tendons that can be used in transposition are shown in the table.

For transpositions As a rule, it is best to use a tendon whose direction of pull and amplitude of sliding does not differ from the tendon-muscle motor being replaced. When considering the extensor tendon from these two points of view, it turns out that the requirements are best met, first, by the tendon of the extensor extensor of the index finger, and secondly, by the tendon of the long radial extensor of the hand.

The first of these was first used for this purpose by Mensch (1925), and in the recent past its use has been recommended by many authors (Bunnell, Pulwertaft, Christoph) and especially J. Böhler. The advantage of the long radial extensor is its anatomical proximity to the rupture site and the fact that the direction of its thrust acts from the ulnar side. Given its anatomical location, the tendon is recommended for transposition by Schlatter and Fett. The disadvantage of this tendon is that it has less movement than the extensor pollicis longus tendon.

Transposition of the tendon of the own extensor of the index finger Strendell performs as follows: the tendon of the own extensor of the index finger is crossed over the head of the II metacarpal bone through a transverse skin incision of 1 - 2 cm. The distal end of the tendon is attached to the tendon of the common extensor of the index finger so that when the finger is straightened, it resists the rotation of the index finger. Within the wrist, according to the location of the tendon, a longitudinal skin incision is made, through which the cut tendon of the own extensor of the index finger is removed.

Then, using new cut at the level of the middle of the I metacarpal bone, the stump of the tendon of the long extensor of the thumb is released, and then it is connected "end to end" with the tendon of the own extensor of the index finger, held under the skin.

Rupture of the tendon of the long extensor of the thumb due to a fracture of the radius

Case of own observation: B. I., a 28-year-old teacher, received a fracture of the radius in a typical place with a slight displacement of the fragments. After reposition, four weeks of fixation and three weeks of functional therapy following the removal of the plaster cast (Fig. a), the patient felt healthy. However, on the eighth week, while cleaning the apartment, in the absence of any strong movements, the patient felt a crunch in her thumb, after which it became impossible to straighten it. The position of the thumb, typical for a rupture of the extensor tendon, is shown in Fig. b.

• The long extensor of the thumb (lat. Musculus extensor hallucis longus) is the muscle of the lower leg of the anterior group.

  Lies between the anterior tibial muscle (lat. M. tibialis anterior) and the long extensor of the fingers (lat. M. extensor digitorum). The upper two-thirds of the long extensor of the finger is covered by these muscles.

  The muscle originates from the medial surface of the middle and lower thirds of the fibula and the interosseous membrane of the lower leg and, heading down, passes into a narrow long tendon, which passes under the lat along the middle canal. retinaculum mm. extensorum inferius to the big toe. It attaches to the distal phalanx. Part of its bundles fuses with the base of the proximal phalanx.

Related concepts

References in literature

long extensor thumb brushes. Along the radial edge of the forearm, it reaches the ulnar fold, then rising to the outer-posterior surface of the shoulder to the acromial process of the scapula and further to the seventh cervical vertebra. From this point, the meridian goes to the supraclavicular region, from where one of its branches goes deep into the body to the large intestine, and the second - along the neck, crossing the lower jaw in front of its angle. There he makes a turn, moving to the opposite side. In the nasolabial groove, it intersects with an identical meridian running along the other side of the body. There are 20 points along the meridian.

2. Meridian of the large intestine. Pair meridian. Refers to the Yang system. It starts from the nail bed of the index finger, runs along its radial edge, then goes between the first and second metacarpal bones and between the tendons of the short and long extensor thumb brushes. Along the radial edge of the forearm, it reaches the ulnar fold, then rising to the outer-posterior surface of the shoulder to the acromial process of the scapula and further to the seventh cervical vertebra. From this point, the meridian goes to the supraclavicular region, from where one of its branches goes deep into the body to the large intestine, and the second - along the neck, crossing the lower jaw in front of its angle. There he makes a turn, moving to the opposite side. In the nasolabial groove, it intersects with an identical meridian running along the other side of the body. There are 20 points along the meridian.

Related concepts (continued)

The pectoralis major muscle (Latin musculus pectoralis major) is a large superficial fan-shaped muscle located on the anterior surface of the chest. Under it is a triangular small pectoral muscle.

Round pronator (lat. Musculus pronator teres) is the thickest and shortest muscle of the surface layer. Two heads are distinguished in it: a large humeral head (lat. caput humerale), which starts from the medial epicondyle of the humerus, medial intermuscular septum of the shoulder and fascia of the forearm, and a smaller ulnar head (lat. caput ulnare), lying under it and originating from medial edge of the tuberosity of the ulna. Both heads form an abdomen somewhat flattened from front to back, which ...

The quadriceps femoris muscle (lat. Musculus quadriceps femoris) - occupies the entire front and partly the lateral surface of the thigh. Consists of four heads.

The muscles of the upper limbs provide freedom and a wide variety of arm movements. The muscles of the upper limb are usually divided into the following groups: 1) muscles shoulder girdle; 2) muscles of the free upper limb - shoulder, forearm and hand.

The sartorius muscle (Latin musculus sartorius) is the muscle of the anterior thigh group. It is the most long muscle human body.

The latissimus dorsi (lat. musculus latissimus dorsi) is a superficial muscle that occupies the entire lower part back, the upper bundles in the initial part are covered by the trapezius muscle.

The small round muscle (lat. Musculus teres minor) is an oblong, somewhat rounded cord, the muscle bundles of which are parallel to each other.

The triceps muscle of the shoulder (triceps; lat. musculus triceps brachii) is the extensor muscle of the posterior group of the shoulder, occupies the entire back side of the shoulder, consists of three heads - long (caput longum), lateral (caput laterale) and medial (caput mediale).

The large round muscle (lat. Musculus teres major) is flat and elongated in shape. All over in the back section is covered latissimus dorsi back, in the outer section - the long head of the triceps muscle of the shoulder, deltoid muscle, and in the middle section - a thin fascia.

The biceps muscle of the shoulder (biceps, lat. musculus biceps brachii) is a large muscle of the shoulder, clearly visible under the skin, due to which it is widely known even among people who are new to anatomy.

The coracobrachialis muscle (lat. Musculus coracobrachialis) is flat, covered throughout by the head of the biceps brachii. The muscle starts from the top of the coracoid process of the scapula and is attached below the middle of the medial surface of the humerus along the crest of the lesser tubercle.

The gluteus maximus muscle (lat. Gluteus maximus) is the largest muscle of the three gluteal muscles, which is closest to the surface. It makes up the bulk of the form and appearance buttocks.

In terms of location, action and number, the muscles of the toes are almost similar to the muscles of the fingers of the hand, but, as already indicated, depending on the little developed activity of the toes, the muscles of the rear of the foot are more related to movement in the ankle joint, and the muscles of the plantar side are involved in strengthening the arch of the foot.

Extensors and flexors of the toes

Between the extensors of the fingers (dorsal flexors) and their flexors (plantar flexors) we find long and short extensors, as well as long and short flexors. The first are located on the front surface of the lower leg and on the back of the foot, the second - on the back surface of the lower leg and on the sole.

Among the extensors we have the extensor digitorum longus and the extensor hallucis longus, which have already been described above; it remains for us to disassemble only the short extensors of the fingers.

Short finger extensor(m. extensor digitorum brevis, Fig. 72-11) begins on the dorsum of the calcaneus; its innermost part stands out under the name short extensor thumb (m. extensor hallucis brevis, Fig. 72-22). At the level of the metatarsal bones, the muscle fibers pass into the tendons of the first four fingers. All of them obliquely fit (outside inwards) to the outer side of the tendons of the long extensor and merge with them at the base of the first phalanx, except for the tendons of the thumb. The tendon of the short extensor of the thumb is attached directly to the first phalanx.

The short extensor of the fingers mainly acts on the first phalanges. The oblique arrangement of its tendons allows the abduction of the fingers outward in the metatarsophalangeal joint. Acting simultaneously with the long extensor of the fingers, the short extensor produces pure extension of the fingers at the metatarsophalangeal joint. The tendon of the short extensor of the first finger, attaching directly to the first phalanx, produces its extension.

Innervation: deep peroneal nerve (n. peroneus profundus, L IV-V and S I).

Among the flexors of the fingers, there are: a long flexor of the thumb and a common long flexor of the fingers with an additional head starting from the calcaneus, a square muscle of the sole and a short common flexor of the fingers. In addition, there is a short flexor for both the thumb and little finger.

flexor digitorum longus(m. flexor digitorum communis longus, Fig. 66-7) is located in the deepest layer of the lower leg. It starts from two-thirds of the posterior surface of the tibia, in addition, part of its fibers originate from the tendon arch formed by the fascia. tibialis muscle.

So start it muscle fibers reaches the fibula. The posterior tibial muscle, approaching the formed tendon of the long flexor, crosses it and is located directly near the inner ankle. The tendon of the long flexor of the fingers, going down, is located closer to the midline of the lower leg and passes to the sole. On the sole, it receives a tendon stalk from the long flexor of the thumb and, in addition, from the lower and inner surface heel bone, a short additional head is attached to it - square muscle soles(m. quadratus plantae, s. sago quadrata Sylvii, Fig. 66-23). Then, at the level of the base of the metatarsal bones, the common tendon of the long common flexor of the fingers splits into four bundles, which immediately give rise to the so-called vermiform muscles, leaving from the inside (from the side of the first finger) side of its tendons. Moving further forward, each tendon of the common long flexor lies in a channel formed by the bifurcation of the corresponding tendon of the short flexor, just as it was on the hand of the superficial and deep flexors of the fingers. Located together with the short common flexor "of the fingers in the bone-fibrous sheath of the fingers, the tendons of the long flexor end, attaching to the third (nail) phalanges of the fingers -

The long common flexor of the fingers flexes the third phalanges over the second and the second over the first; at the maximum of its contraction, it can somewhat bend the first phalanx over the metatarsal bone; in addition, it informs the IV and V fingers of some deviation inwards, which is especially evident in the position of their nail phalanges. This last action is explained by the oblique (inside outward) direction of the tendons of the IV and V fingers on the sole. If the action of its accessory head and the action of the short common finger flexor are added to the action of the general long flexor of the fingers, then this deviation is destroyed.

Duchenne and Poirier completely deny the action of the long common flexor of the fingers on the ankle joint during the upper support. Braus, on the other hand, believes that with the upper support, the common long flexor of the fingers can produce plantar flexion, supination (turning the sole inside) and abduction medially (from the midline of the foot), with supination most pronounced, plantar flexion the least, and abduction medially corresponds to the action posterior tibial muscle. When a person is in a standing position, the long flexor of the fingers strengthens the arches of the foot and can extend the lower leg (plantar flexion) when raising the torso on toes.

Innervation: tibial nerve (n. tibialis, L V and S I).

Short common finger flexor(m. flexor digitorum communis brevis, Fig. 74) starts from the lower surface of the calcaneal tubercle, from the posterior third of the upper surface of the plantar aponeurosis and from the intermuscular septa. At the level of the base of the metatarsal bones, it forms four tendons, which split longitudinally at the level of the first phalanges and, having passed the corresponding tendons of the long

the common flexor of the fingers, pass through the bone-fibrous sheath and are attached to the sides of the second phalanges, reaching their articulations with the third. Their attitude and construction are quite consistent with the attitude and construction of the superficial and deep flexor of the fingers, which were described above. The tendon of the flexor of the fifth finger is sometimes very thin and is not pierced by the tendon of the common long flexor of the fingers, sometimes it is completely absent.

The short common flexor of the fingers flexes the second (phalanges) and almost does not show 4 its action on either the first or third phalanges. With a lower support, its main action is to strengthen the longitudinal arch of the foot (Fig. 74) and plantar aponeurosis.

Innervation: plantar internal nerve (n. plan-taris medialis, L V and S I).

flexor thumb longus(m. flexor hallucis longus, Fig. 66-19, 15) is the most external muscle deep posterior muscle layer of the lower leg; it begins on the middle lower third of the posterior surface of the fibula; going down and inside, it passes into the tendon, located in the groove located on the posterior surface of the talus, fits under the internal process of the calcaneus (sustentaculum tali) and goes to the inner edge of the foot.

On this path, the tendon of the long flexor of the thumb crosses with the tendon of the long common flexor of the fingers, connects to it with a tendon bundle and then, passing between both parts of the short flexor of the thumb and both sesamoid bones of the metacarpophalangeal joint of the thumb, reaches its nail phalanx, where it attached (Fig. 74-4).

The long flexor thumb strongly flexes the second phalanx and has little effect on the metatarsophalangeal joint. Duchenne completely rejects its influence on the ankle joint. According to Braus, the flexor hallucis longus plays a large role in pushing the foot off the ground. It is also necessary to note its importance in relation to the movements of the entire foot. It is predominantly a plantar flexor, but at the same time, with the upper support, it abducts the foot inwards and supinates it. With lower support, the long flexor of the big toe strengthens the arch of the foot in the longitudinal direction and counteracts the formation of a flat sole (pes planum).

Innervation: tibial nerve (n. tibialis, L V and S I-II).

Flexor thumb short(m. flexor hallucis brevis, Fig. 74-2; 75-1) is divided into two parts. Both of its parts start from the sphenoid bones, from the ligamentous apparatus connecting the plantar surface of the calcaneus and metatarsal bones, and from the plantar aponeurosis. Heading towards the thumb along the metacarpal bone, the short flexor of the thumb is divided into two parts and attached to the tubercle of the first phalanx: one on the outside, the other on the inside. Both tendons have sesamoid ossicles.

Rice. 75. deep muscles feet. (Poirier.) 1 - short flexor of the thumb, 2 - transverse head of the adductor thumb muscle, 2 "- oblique head of adductor muscle of the thumb, 3 - short flexor of the V finger, 4 - muscle opposing the V finger, 5 - tendon of the long peroneal muscle - its course along the plantar surface and attachment

The short flexor thumb flexes the thumb at the metatarsophalangeal joint, which is especially important when standing on toes. Acting with separate heads, the short flexor of the thumb can abduct the first phalanx to one side and the other (from the midline of the foot). Starting from the deep ligamentous apparatus of the foot and to the side of the plantar aponeurosis, it strengthens, together with other muscles, the internal longitudinal arch of the foot.

Fifth finger flexor short(m. flexor digiti quinti, Fig. 75-3) starts from the fibrous sheath of the long peroneal muscle, from the crest of the lower surface of the cuboid bone, from the base of the metatarsal bone of the fifth finger and is attached to the base of the first phalanx of the fifth finger. It flexes the V finger at the metatarsophalangeal joint, and also strengthens the outer longitudinal arch of the foot through the plantar aponeurosis.

Innervation: external plantar nerve (n. plantaris lateralis, S I-II).

Muscles that abduct the toes to kick three and outward from the midline of the foot

Abduction, which is possible in the metatarsophalangeal joints, is performed in the same way as on the hand, by means of the interosseous and vermiform muscles, and in the thumb and small fingers, also by specially abducting muscles. Only the opposing muscle of the thumb is missing here; as for the same muscle of the fifth finger, it is sometimes observed. On the foot, as well as on the hand, in this group there should be 10 abductor and adductor muscles. Of these, the muscles that abduct and adduct the thumb, as well as the abductor of the thumb, are located on the sole, and the rest are between the metatarsal bones, which is why they, like the muscles of the hand, are called interosseous. The vermiform muscles, which were mentioned in the description of the long common flexor of the fingers, being located on the inside of its tendons, also take part in the abduction of the II finger and the adduction of the III, IV and V fingers.

On the foot, the middle line, towards which adduction (adductio) will be performed and away from which abduction (abductio) will be performed, coincides with the middle line of the second finger. Thus, only the second finger will have two interosseous muscles that abduct to both sides of the midline, while the remaining fingers will have interosseous muscles that abduct from the midline and lead to it.

At the thumb, we have an independent muscle that abducts the thumb and an independent adductor.

Abductor thumb muscle(m. abductor hallucis, Fig. 74-3) lies superficially under the fascia on the inner edge of the foot and forms an elevation of the thumb. The abductor muscle starts directly from the lower part of the inner surface of the calcaneal tubercle, as well as from the ligamentous apparatus of the foot and plantar aponeurosis; it is attached by a well-developed tendon to the inner edge of the first phalanx, fusing with the tendon of the inner head of the short flexor of the thumb. Sometimes the abductor thumb muscle sends a tendon extension to the extensor tendon of the thumb. It produces the abduction of the thumb from the midline of the foot, in which it is partly helped by the inner head of the short flexor of the thumb.

The muscle that abducts the thumb can be attributed to a static type: pinnate arrangement of fibers (powerful tendon). Its main value is to strengthen the inner arch of the foot. Abduction of the thumb is weakly expressed.

Innervation: internal plantar nerve (n. plantaris medialis, L V and S I).

adductor thumb muscle(m. adductor hallucis, Fig. 75-2, 2 ") consists of two heads. One of them, obliquely located, starts from the cuboid bone, from the third sphenoid, second and third metatarsal bones, and also from the fibrous sheath of the long peroneal muscle and goes obliquely from the middle of the foot to the first finger.The second head, transversely located, starts from the head of the metatarsal bone of the fourth finger and, on the way to the first finger, crosses the heads of all other metacarpal bones in the transverse direction, receiving separate muscle bundles from them and from the intermetatarsal ligaments.

The obliquely located head, approaching the first finger, fuses with the outer head of the short flexor of the thumb and together with it will bring the thumb to the midline of the foot. The transversely located head of the adductor thumb muscle is more independent than was observed on the hand, and some (Lebuk) even indicate that this muscle has an independent attachment on the first phalanx: on the one hand, it sends a continuation to the rear of the thumb to its extensor , on the other hand, part of the fibers, passing through the attachment of the oblique head of the adductor muscle of the thumb and its short flexor, ends at the bone-fibrous sheath of the thumb. The oblique head has the strongest adductor effect on the first phalanx of the big toe and, as Duchene points out, is an active ligament that does not allow the heads of the metatarsal bones to diverge, and thus strengthens the transverse arch of the foot.

Innervation: internal and external plantar nerves (n. n. plantares medialis et lateralis, S I-II).

Abductor fifth finger muscle(m. abductor digiti quinti, Fig. 74-5), like the muscle that removes the thumb, is located superficially, but only on the outside. The muscle abducting the V finger begins from the lower surface of the posterior external tubercle of the calcaneus, from the inward surface of the plantar aponeurosis and from the intermuscular septum that separates it from the short flexor of the fingers. Heading forward along the metacarpal bone of the fifth finger, it ends on the outer surface of the base of the first phalanx of the fifth finger and on the lower surface of the bursal ligament of the metatarsophalangeal joint.

In most cases, the muscle that abducts the V finger is only a flexor of the first phalanx, and only in children can it still be abducted. Being located on the outside from the heel to the main phalanx of the fifth finger, it, of course, has a great influence on strengthening the outer arch.

Innervation: external plantar nerve (b. plantaris lateralis, S I-II).

The abduction and adduction of the remaining fingers is performed with the help of the interosseous muscles; they are located like the interosseous muscles of the hand, on the one hand, in the deepest layer on the sole (interosseous internal muscles), on the other hand, on the back of the foot (interosseous external muscles). As on the hand, there are three internal interosseous muscles on the foot, four on the outside; the inner ones will lead to the midline of the foot, the outer ones will lead away from the midline; you just need to remember that the midline of the foot passes through the second toe and therefore two abductors will be at the second toe, and not at the third, as we saw on the hand.

Adductor internal interosseous muscles(m. m. interossei interni, Fig. 76) start from the posterior third of the lower edge of each of the last three metacarpal bones (V, IV and III) and from the lower surface of their base. They lie more superficial than the interosseous spaces themselves, so that they completely cover the lower surface of the metacarpal bones. They end in a completely different way than the internal interosseous muscles of the hand: in most cases, they are attached only to the lateral internal (from the side of the thumb) part of the first phalanx and to the bursal ligament of its joint; they do not continue to the extensor tendon of the fingers.

According to their location and attachment, the internal interosseous muscles are the muscles leading to the midline of the foot III, IV and V fingers; the second finger has no adductor muscle, since it lies on the midline of the foot, and the big one has its own adductor, described above (Fig. 75-2).

Innervation: deep branches of the external plantar nerve (rami profundi n. plantaris lateralis, S I-II).

Abductor external interosseous muscles(m. m. interossei externi, Fig. 77) are located on the back of the foot, fulfilling all the gaps between the metacarpal bones. They are biceps and start from the lateral parts of the metacarpal bones facing each other, from the lower surface of their bases and the dorsal interosseous fascia. Starting from two opposite sides, they form pennate muscles, the tendons of which are attached to the base of the first phalanges and to the bursal ligament of the joint on the outside of the III and IV fingers and on both sides of the II finger. They do not continue to the extensor tendon of the fingers; rather, you can find continuations to the cartilaginous thickenings of the bag of the metatarsophalangeal joint.

The interosseous muscles of the IV, III and II fingers are abducting from the midline of the foot. These movements in the foot are very limited, as they are constantly constrained by shoes, and are most marked in children or people who do not wear shoes. Approaching the first phalanx from both sides, more from the plantar surface, and combining its action with the action of the internal interosseous muscles, the external interosseous muscles of the IV, III and II fingers bend the first phalanx; the same movement is produced by the abductor V finger in combination with the internal interosseous V finger.

Innervation: deep branches of the external plantar nerve (n. plantaris lateralis, S I-II).

vermiform muscles(m. m. lumbricales,) mentioned above when describing the long common flexor of the fingers, from the tendons of which they begin, also take part in the abduction of the fingers. Located on inside each tendon of the II, III, IV and V fingers, they are attached to the inside of the first phalanges of the same fingers, and, therefore, will contribute to the work of the interosseous muscles that produce abduction in their direction. In the second finger, they will produce abduction from the midline, and in the remaining (III, IV and V) fingers, they will lead to the midline.

The vermiform muscles, to a certain extent, can participate in the flexion of the first phalanges.

Innervation: internal plantar nerve (n. plantaris medialis); external plantar nerve (n. plantaris lateralis to the first, third and fourth, L V and S I-II).

To the muscles of the foot, one must also add a non-permanent muscle that opposes the fifth finger.

Opposite V finger muscle(m. opponens digiti quinti, Fig. 75-4). Man does not have an opposing muscle of the thumb, since the thumb, being one of the main points of support, has lost all significance for grasping. The opposing muscle of the fifth finger is important for adapting the sole to uneven ground. Even when it exists, it is poorly developed and not completely separable from the flexor brevis and abductor digit V. It differs from the muscles mentioned only in that it is attached not to the first, but to the metacarpal bone of the fifth finger. During its contraction, the muscle opposing the V finger pulls the metacarpal bone somewhat inward (towards the midline of the foot) downwards.

Despite the apparent simplicity of movement, flexion and extension of the toes requires the effort of several muscles. Their well-coordinated work allows not only to move the fingers, but also to raise the foot itself. Interestingly, there is a separate muscle for the thumb, while all the rest move synchronously.

What muscle flexes the fingers

Long extensor toes

The long extensor of the fingers is part of the anterior muscle group of the lower leg and is located along its lateral edge. This anatomical formation begins at the level of the upper third of the tibia, attaching to the anterior edge of the fibula.

Descending towards the foot, the muscular part is transformed into a thin but strong tendon.

It is it that is subsequently divided into four thinner tendon bundles, one for each finger.

The place of attachment is the proximal ("near") phalanx. At the place of fixation, it is additionally divided into three small beams, with which you can use any, even the smallest part of the foot.

The long extensor also has an additional purpose. Together with the synergistic muscle (the third peroneal), it raises the outer edge of the foot, the action is called pronation. If it is firmly fixed, it brings the lower leg closer to it.

Which muscle is responsible for finger flexion

Muscles of the foot: dorsal and plantar

The long finger flexor allows you to properly push off the surface when walking or running. Also, this muscle formation is involved in maintaining the balance of the whole body in a standing position.

This muscle belongs to the posterior group of the lower leg and starts from the posterior surface of the tibia. Descending to the foot through the calcaneus, it is attached from below to the distal phalanges of the 2nd, 3rd, 4th and 5th fingers.

But do not think that the function of this muscle is limited only to the movement of the fingers.

It plays a huge role in the flexion of the foot itself and its supination.

When putting on a toe and maintaining balance in this position, you can’t do without it!

The correct formation of muscle fibers, their normal tone allows the arch of the foot to occupy the correct anatomical position. This prevents the formation of flat feet.

How to check the performance of the flexor

Functional Muscle Tests

At various diseases the force of muscle contraction may weaken. In order to find out, there are a number of simple tests:

1. With one hand, the trainer or doctor holds the metatarsus in one position, and with the other, gently but firmly tries to bend the toes. The patient should try to straighten them, tensing the corresponding muscles as much as possible. If successful, muscle strength is assessed as 4 or 5 points (the maximum possible score).
2. The patient lies on his back, a soft roller is placed under his knee (you can roll up a towel). When forcibly holding the metatarsus, you must try to straighten your fingers. (2 or 3 points).
3. The situation is no different from the previous one. A trainer or physician palpates the extensor tendon. With a successful attempt to straighten the fingers, 1 point is assigned.

Normally, the muscle strength of a healthy person is estimated at 5 points. With insufficient nutrition or tissue innervation, it gradually decreases.

All exercises must be done carefully so as not to get an ankle sprain.

How does the thumb move?

Finger extensor stretch

The mechanics of his movements depends on several muscles at once. Such a complex anatomy is explained by the fact that it is this finger that largely ensures the balance of a person and makes him upright.

The long flexor of the thumb belongs to the posterior muscle group of the lower leg and, descending to the plantar part, is transformed into a tendon.

Interestingly, in the groove between the calcaneus and talus, the tendon of the pancake flexor of the thumb "gives" some of the fibers to the tendon of the long flexor.

Thus, this muscle is involved in the flexion of all toes to a greater or lesser extent.

The long extensor of the thumb belongs to the opposite, anterior muscle group of the lower leg. At the same time, going down, it passes into a thin, but very strong tendon of the long extensor.

Why muscle function can be impaired

Various diseases of muscle tissue and tendons can affect the quality of their work. A decrease in muscle tone can occur for several reasons:

• senile (age-related) atrophy due to metabolic disorders;
• failure of the endocrine system;
• chronic and systemic connective tissue diseases;
• fertentopathy, genetically determined diseases;
• polyneuritis, polyneuropathy of peripheral nerves;
• post-traumatic complications;

Separately, it is worth talking about tendinitis. With this disease, the tendon tissue of the long extensor of the big toe suffers, the cause is acute inflammation. Muscle structures of various sizes can also be involved in this pathological process. Dystrophic processes under certain favorable conditions can become chronic.

In diabetes mellitus, polyneuropathy of the lower extremities can lead to significant and serious tissue malnutrition at the local level.

A frequent complication of this disease is progressive lameness, problems with trophism up to the formation of dry gangrene.

With prolonged systemic use of certain medications, persistent pain in the foot may occur. This is due to the deposition of salts in the bone tissue, the formation of neoplasms or growths.

Valgus or varus deformity of the foot is one of the main non-surgical problems in traumatology. Its curvature with deviation inward or outward not only does not look aesthetically pleasing, but also significantly reduces the quality of life.