Muscles of the limbs. Muscles acting on the human shoulder joint Which muscles do not act on the shoulder joint

pectoralis major muscle massive, fan-shaped, occupies a significant part of the anterior chest wall. According to the places of its beginning, the clavicular part starts from the medial half of the clavicle; the sternocostal part originates from the anterior surface of the sternum and the cartilages of the upper six ribs; the abdominal part (weakly expressed), starts from the anterior wall of the vagina of the rectus abdominis muscle. The bundles of parts of the pectoralis major muscle, converging noticeably, pass in the lateral direction and are attached to the crest of the greater tubercle of the humerus. The pectoralis major muscle is separated from the deltoid muscle by a well-defined deltoid-pectoral groove, which passes upward and medially into the subclavian fossa. Located superficially, this muscle, together with the pectoralis minor muscle, forms the anterior wall of the axillary cavity and limits the axillary fossa with its lower edge. The muscle of the raised arm lowers and leads to the body, while turning it inward. If the arm is strengthened in a raised position, it lifts the ribs and sternum (auxiliary respiratory muscle), contributing to the expansion of the chest.

pectoralis minor muscle flat, triangular in shape, located directly behind the pectoralis major muscle. Starts from 2-5 ribs, near their anterior ends. Heading upward and laterally, it is attached by a short tendon to the coracoid process of the scapula. The muscle tilts the scapula forward; with a strengthened shoulder girdle, it raises the ribs, contributing to the expansion of the chest.

subclavian muscle small in size, occupies a slit-like gap between 1 rib and clavicle. It starts from the cartilage of the 1st rib, passes in the lateral direction and is attached to the lower surface of the acromial end of the clavicle. The muscle pulls the collarbone down and forward, helping to strengthen the sternoclavicular joint.

Serratus Anterior wide, quadrangular, adjacent to the chest from the side, forms the medial wall of the axillary cavity. It starts with large teeth from the upper eight to nine ribs and is attached to the medial edge and lower angle of the scapula. Its upper and middle bundles lie horizontally, the lower ones are oriented obliquely and pass from front to back and from bottom to top. The lower 4-5 teeth of the serratus anterior, where they begin, go between the teeth of the external oblique muscle of the abdomen. The muscle moves the scapula, especially its lower angle, forward and laterally; the lower bundles contribute to the rotation of the scapula around the sagittal axis, as a result of which the lateral angle of the scapula moves upward and the medial arm rises above the horizontal. With a reinforced shoulder blade, the anterior serratus muscle raises the ribs, contributing to the expansion of the chest.

1. Anterior muscle. Beginning - fills the entire supraspinatus fossa, covered by the trapezius and brachio-atlantic muscles. It bifurcates over the supraarticular tubercle of the scapula into two tendons - lateral and medial.

Function- flexes the shoulder joint.

blood supply:

2. Deltoid muscle. It is located on the lateral (lateral) surface of the scapula and shoulder joint. Consists of the scapular and acromial parts.

a) The scapular part starts from the scapular spine and from the infraspinatus muscle.

b) The acromial part originates from the infraspinous joint and ends at the deltoid roughness of the humerus.

Function

blood supply: posterior circumflex humeral artery, thoracoacromial artery.

3. The occipital muscle. Fills the infraosseous fossa of the scapula, covered by the deltoid muscle, proximally has a tendon bursa.

Function- limb abduction.

blood supply:

4. Small round muscle. Lies under the deltoid muscle, goes from the lower third of the caudal edge of the scapula to a small round roughness.

Function- flexes and rotates the shoulder joint outward.

blood supply: artery that circumflexes the scapula.

5. Large round muscle. It goes from the caudal angle of the scapula to a large round roughness.

Function- flexes and rotates the shoulder joint.

blood supply: subscapular artery.

6. Coracobrachial muscle. It begins on the coracoid process of the scapula.

Function- helps to straighten the shoulder joint.

blood supply: anterior and posterior arteries surrounding the humerus.

7. Subscapularis muscle. It goes from the subscapular fossa to the medial muscular tubercle of the humerus.

Function- leads the thoracic limb.

blood supply: subscapular artery.

muscles shoulder girdle, their blood supply, topography and functions.

The muscles of the shoulder girdle connect the trunk with the thoracic limb.

1. Trapezius muscle. It goes from the spine to the outer surface of the scapula (awn).

Functions

blood supply: transverse artery of the neck, suprascapular, occipital arteries, posterior intercostal arteries.

2. Rhomboid muscle. Lies under the trapezius muscle. Goes to the cartilage of the scapula.

Functions: holds the scapula on the body.

blood supply: deep cervical and transverse cervical arteries.

3. The latissimus dorsi muscle starts from the primordial to the last lumbar vertebrae on the humerus (on the inside).

Functions: pulls back the chest limb.

blood supply: thoracic artery, posterior circumflex artery, posterior intercostal arteries.

4. Atlantoacromial muscle. It is located on the lateral surface of the neck between the wing of the atlas and the acromion of the scapula.

Functions: turns the head to the sides and lowers it down.

blood supply: transverse cervical and common carotid arteries.

5. Superficial and deep pectoral muscles located between the sternum and limb.

Functions: bring the limbs to the body.

blood supply: deep thoracic artery.

6. Ventral serratus muscle. It goes from the ribs and cervical vertebrae to the shoulder blade in the form of a fan.

Functions: the main holder of the torso between the limbs.

blood supply: dorsal scapular (transverse cervical) and intercostal arteries.

7. The sternocleidomastoid muscle. Extends along the lateral surface of the neck from the humerus to the head.

Function: brings the limb forward.

blood supply: vertebral and common carotid arteries.

Muscle. Chemical composition, physical properties and functions.

Muscles are a typical parenchymal organ. The parenchyma is the first structure, the main working part, characterizing the organ from the functional side. Represented by bundles of skeletal striated muscle tissue, function reduction.

The second structure - the stroma (skeleton) is a connective tissue structure, in the form of a shell and performs a protective function. Each muscle is tightly surrounded on the outside by a connective tissue sheath in the form of a case and is called the external peremizium. Contains a small amount of fat. Blood, lymphatic vessels and nerves penetrate into the muscle from the side of the external truncation. And they are also introduced into the connective tissue layers - the internal peremisium. Separating the muscle in the form of partitions into a number of large sections located along the fibers. Layers depart from the internal remysium - endolisium, which divides into smaller sections. As a result, the cross section of the molecules has a mosaic appearance.

In the fusiform muscles, the tendon has a light yellow color, consists of dense connective tissue, the fusiform muscles are located closer to the head, and the tail is located closer to the moving point. The tendons are a non-fatiguing part, the elasticity softens the jerks and makes the movements smooth. In some cases, on the trunk, the muscles pass into wide lamellar tendons; this is called aponeuroses.

Chemical composition:

75% water, 25% organic matter, 20% protein, 2% fat. After slaughter, an obligatory companion - fat, which is deposited in connective tissue formations, is a necessary plastic material, the main source of water. The melting point of fat varies from animal to animal. Physical properties:

1. extensibility - the ability to change length under the influence of an applied force

2. elasticity - the ability of a muscle to restore its original shape after the cessation of the forces that cause its deformation.

3. muscle strength - the maximum load that the muscle can still lift.

4. muscle work - the product of the lifted load by the height of the lift.

Functions: extensor, rotation - outward, inward, dilator, constrictor, adductor, abductor, tensioner, lifter.

The functions of the muscles of the shoulder girdle are associated with the functions of the muscles of the chest and partly of the back. Therefore, the distinction between the trunk and the shoulder girdle is very arbitrary. With a change in the outlines of the muscles, the outlines of the back, neck and chest also change.

The muscles of the shoulder girdle include:

  • shoulder muscle
  • Subscapularis
  • Coracobrachial muscle

The shoulder joint is spherical. It is formed by the head of the humerus and the glenoid cavity of the scapula. This joint allows you to perform flexion (raising the arm forward) and extension (pulling the arm back) of the arm in the shoulder joint, adduction (movement of the arms in a horizontal plane at shoulder level forward) and breeding (movement of the arms in a horizontal plane at shoulder level back) of the arms, rotation arms in and out, abduction (to the side) and adduction (to the lateral surface of the body) of the arm.

Deltoid

The deltoid muscle has the shape of a triangle with the apex facing down. The muscle consists of three bundles, each of which is responsible for the movement of the hand in different directions. Accordingly, three parts of the deltoid muscle are distinguished: clavicular, acromial and scapular. Starting with a wide tendon located above the shoulder joint, three bundles of the deltoid muscle converge into one tendon, which is attached to the humerus. good development deltoid muscle affects the width of the shoulders, despite the fact that their bone base can be quite fragile. All three parts of the deltoid muscle can contract independently of each other.


front beam the deltoid muscle is attached to the collarbone and raises the arm forward (flexion of the arm at the shoulder joint), side beam(lateral) attaches to the acromion of the scapula and raises the arm to the side (arm abduction). Back beam deltoid muscle is attached to the scapula and takes the arm back (extension of the arm in the shoulder joint).


Rotator cuff

The rotator cuff is a group of four muscles that form a protective sleeve around the shoulder joint. Although these muscles are hardly visible, they are extremely important for stability and strength of the shoulder. All four muscles start from the scapula and, passing around the shoulder joint, are attached to the humerus.


Supraspinatus muscle covered for the most part trapezius muscle, but since the latter is rather thin in this part, it cannot completely hide the outline of the supraspinatus muscle. The supraspinatus muscle is located in the supraspinatus fossa of the scapula and is attached to the greater tubercle of the humerus and is responsible for abduction to the side. upper limb and rotating it outwards.


infraspinatus muscle starts from rear surface scapula and attaches to the humerus. teres minor muscle is a synergist of the subscapularis muscle and the scapular part of the deltoid muscle. The infraspinatus and small round muscle are located behind the joint. They raise their arm to the side and take it back, rotating the shoulder outward (supination).

Subscapularis broad, thick, triangular in shape. Occupies almost the entire costal surface of the scapula. It is placed in front of the joint and rotates the arm inward (pronation), while bringing the shoulder to the body.

In the region of the pectoral limbs, the muscles are located: 1) the shoulder girdle; 2) shoulder joint; 3) elbow joint; 4) carpal joint and 5) finger joints.

Rice. one. Distribution scheme muscle groups on the chest (A - from the lateral surface, B - from the medial):

1 - extensors of the shoulder joint; 2- abductors of the shoulder joint; 3 - extensors of the elbow joint; 4, - wrist extensors; 5 - finger extensors; 6 - flexors of the shoulder joint; 7 - wrist flexors; 8 - finger flexors; 9 - adductors of the shoulder joint; 10 - flexors of the elbow joint.

Shoulder muscles

In the shoulder multiaxial joint, extension and flexion, abduction and adduction are possible, as well as, albeit to a weak degree, pronation and supination of the free limb.

Extensors (extensors) pass through the top of the shoulder joint, flexors (flexors) are located inside the angle of the joint. The abductors lie on the lateral surface of the scapula, and the adductors lie on the medial surface of the scapula.

Flexors help latissimus dorsi back, the long head of the triceps brachii, and the deep pectoral muscle. The pectoral muscles help the adductors, and the rhomboid muscle helps the abductor. Pronators are assisted by the brachiocephalic and thoracic superficial muscle and the latissimus dorsi (Fig. 2 and 3).

Extensors:

1. Prespinous muscle - m. supraspinatus (Fig. 2-4) - pinnate in structure, fills the entire supraspinatus fossa, laterally covered by the trapezius muscle. It ends with two legs on the lateral and medial tubercles of the humerus.

Function - unbends the shoulder joint.

Flexors:

1. Deltoid -m. deltoldeus (13) - flat, fleshy, triangular in shape, lies behind the scapular spine. It covers the infraspinatus muscle, with which it is firmly fused with its initial tendon, as well as the small round muscle and partially the triceps muscle of the shoulder. Consists of scapular and acromial parts.

The scapular part begins with a wide lamellar tendon (aponeurosis) from the scapular spine.

The acromion originates from the acromion. Both parts end on the deltoid roughness of the humerus.

Function - flexes and supinates the shoulder joint.

2. teres minor muscle - m. teres minor (6) - lies behind the infraspina; laterally covered by the deltoid muscle. It starts from the distal third of the caudal edge of the scapula. Ends on the elbow line.

Function - flexes the shoulder joint and supinates it.

3. teres major muscle - m. teres major (7). It starts from the proximal half of the caudal edge of the scapula. It ends on the rounded roughness of the humerus along with the latissimus dorsi muscle.

F u n to c and I - flexes the shoulder joint and pronates it.

Abductors:

1. infraspinalis muscle - m. infraspinatus (5) - fills the infraspinal fossa; covered from the surface by the deltoid muscle. Begins in the posterior fossa. It ends on the lateral tubercle of the humerus.

Adductors:

1. Subscapularis - t. subscapulars (3 - 9) - multi-pinnate, fills the subscapular fossa, in which it is fixed. It ends on the medial tubercle of the humerus.

2. coracobrachial muscle - m. coracobrachial (Fig. 3- 8) . It begins on the coracoid process of the scapula. It ends distally with a round roughness.

Function - helps adductors.

Fig.2. Muscles of the scapula and shoulder from the lateral surface:

A - dogs; B - horses; B - scheme of fixing muscles on bones. 1 - brachiocephalic muscle; 2 - trapezoid m.; 3 - the widest m. of the back; 4 - preosnaya m.; 5 - transverse m; 6 - small round m.; 7 - large round m; 8 - coraco-humeral m.; 9 - subscapular m.; 10 - elbow m.; 11 - tensile fascia of the forearm 12 - biceps m. of the shoulder; 13 - deltoid m., its scapular part; 13 "- deltoid m., its acromial part; 14 - three-headed m. of the shoulder, its long head; and 14" - its lateral head; 16 - dentate ventral m.; 17 - shoulder m.; 18-beam flexor of the wrist.


Rice. 3. Muscles of the scapula and shoulder from the medial surface:

A - dogs; B - horses; D - scheme of fixing muscles on the bones.

Elbow muscles

In a uniaxial elbow joint, only flexion and extension are possible, and in a dog, in addition, rotation of the forearm.

Extensors:

1. Triceps brachii - m. triceps brachii (14) - very powerful, fills the triangular space between the scapula, humerus and olecranon. It consists of three heads: long (two-articular), lateral and medial (single-articular).

Long head - caput longum. It starts from the caudal edge of the scapula, ends on the ulnar tubercle, having underneathtendinous bursa . Helps to flex the shoulder joint.

The lateral head - caput laterale and the medial head - caput mediale start from the proximal third of the humerus, each on its own side. They end on the elbow tubercle.

.2. Elbow muscle - m. anconaeus (10) - lies under the lateral head of the triceps muscle of the shoulder and is firmly fused with it. It starts along the edges of the cubital fossa; ends on the lateral surface of the ulnar tubercle.

3. Tensioner fascia of the forearm - m. tensor fasciae antebrachii (Fig. 3- 11) , lies on the medial surface of the long head of the triceps brachii, along its caudal edge. It starts from the caudal edge of the scapula, ends on the ulnar tubercle and in the fascia of the forearm.

Function - unbends the elbow joint, helps to bend the shoulder joint.

Flexors:

1. Biceps brachii - m. biceps brachii (20) - lies on the anterior surface of the humerus.

It starts from the tubercle of the scapula, approaches in the intertubercular groove of the humerus. In the area of ​​the block of the humerus under the tendon Has a synovial cavity . The muscle ends on the roughness of the radius.

2. shoulder muscle -m. brachialis internus (17) - located directly on the humerus. It starts under the neck of the humerus, ends at the roughness of the radius.

Muscles of the wrist

The carpal joint in domestic animals is uniaxial and allows only flexion and extension.

The abdomens of the muscles acting on the carpal joint are located proximal to the joint and lie at the ends of the forearm, and between the extensors of the wrist are the extensors of the fingers, and between the flexors of the wrist are the flexors of the fingers. (Fig. 86, 87).

Extensors:

1. extensor carpi radialis - m. extensor carpi radialis (Fig. 86- 18) - lies on the dorsal surface of the forearm. It forms the dorso-medial contour of the forearm; begins on the crest of the lateral epicondyle of the humerus, ending at the roughness of the III metacarpal bone.

In the area of ​​the distal quarter of the forearm and on the wrist there is synovial sheath of the tendon - vagina synovialis tendinis.

2. Long thumb abductor - m. abductor pollicis longus (3). It begins on the lateral surface of the radius, crossing the tendon of the radial extensor of the wrist from the dorsal surface, and ends on the head of the II metacarpal bone.

Flexors:

1. Elbow extensor wrists - m. extensor carpi ulnaris (5) . It begins on the extensor epicondyle of the humerus (laterally). It ends on the accessory bone of the wrist.

Function. Only in the dog, the extensor carpi ulnaris extends the wrist, while in ungulates it acts as a wrist flexor.

2. flexor carpi radialis - m. flexor carpi radialis (Fig. 87- 11). It begins on the medial (flexion) epicondyle of the humerus, ends on the head of the metacarpal bone.

The tendon in the wrist is covered with a synovial sheath - vagina synovialis tendinis.

3 . Flexor carpi ulnaris - m. flexor carpi ulnaris (4) - begins on the medial (flexion) epicondyle of the humerus, immediately behind radial flexor wrist, ends in a common tendon on the accessory bone of the wrist.

Muscles of the fingers

Among the muscles acting on the fingers, there are: long digital extensors and flexors, and short finger flexors. The long digital extensors include the common digital extensor and the lateral digital extensor. The abdomens of these muscles lie on the dorsolateral surface of the bones of the forearm, between the extensors of the wrist, and their tendons go to the fingers: from the common digital extensor to the third phalanges of the fingers, and from the lateral digital extensor to the third and second phalanges of the fingers.

The long flexors of the fingers are located on the medio-volar surface of the bones of the forearm, also between the flexors of the wrist; these include superficial and deep digital flexors. Their tendons are directed from the deep flexor of the fingers to the third phalanges, and from the superficial flexor of the fingers to the second phalanges.

Since the long finger muscles are fixed on the epicondyles of the humerus and pass through the ulnar, carpal, metacarpophalangeal, interphalangeal joints, they are polyarticular muscles. Therefore, the extensors of the fingers help the flexors of the elbow joint, extensors of the metacarpus and unbend the metacarpophalangeal joints. The finger flexors, on the other hand, help the elbow extensors, the metacarpus flexors, and each other.

Short digital flexors are located on the volar surface of the metacarpal bones and act on the metacarpophalangeal joints. These muscles in ruminants and horses have evolved into ligaments that suspend the sesame bones.

Extensors:

1. General extensor fingers - m. extensor digitalis communis. It originates on the extensor epicondyle of the humerus and inserts on the extensor process of the distal phalanx.

In the area of ​​​​the wrist there is a synovial sheath of the tendon - vagina tendinis synovitis.

Ruminants have two heads with independent tendons. The medial head adjoins directly to the radial extensor of the wrist and is called the special extensor of the third finger (6).

Function - acts on several joints; it extends the fingers, helps the extensors of the wrist and flexors of the elbow joint.

2. Lateral extensor of fingers - m. extensor digitalis lateralis (1), or in ruminants - a special extensor of the IV finger - lies between the common extensor of the fingers and the ulnar extensor of the wrist. Ends on 2 phalanges of fingers.

Function - unbends fingers and wrist.

Flexors:

1. Superficial finger flexor - m. flexor digitalis superficialis (Fig. 87-9)

It starts just behind the flexor carpi ulnaris and may have 1 or 2 heads. It ends at the distal end of the I and proximal end of the II phalanx of the corresponding finger.

Function - flexes the fingers and wrist, helps the extensors of the elbow joint.

2. Deep finger flexor - m. flexor digitalis profundus (Fig. 87-8) - lies directly on the volar surface of the bones of the forearm. It originates tendinously on the medial epicondyle of the humerus, along with the superficial flexor digitorum. Beneath the tendon is the bursa. On a polydactyl limb, the tendon gives off separate branches for each finger. In the horse, it is attached to the flexor surface of the coffin bone. It is separated from the navicular bone by a mucous bag (bursa).

Function - flexes the fingers and wrist, helps the extensors of the elbow joint.

3. Interosseous muscles - m. interosseus (21) - lie on the volar surface of the metacarpal bones. They start from the common volar ligament of the wrist; terminate in two branches on the sesamoid bones of the metacarpophalangeal joints of each finger.

Muscles of the forearm and paw from the lateral surface.

A - B - dogs; B - pigs; G - cows; D - horses; E - fixing muscles on bones.

1 - lateral extensor of the fingers, 2 - common extensor of the fingers, 3 - long abductor of the thumb, 4 - ulnar flexor of the wrist, 5 - radial extensor of the wrist, 6 - extensor of the 3rd finger, 7 - extensor of the 4th finger, 8 - deep flexor of the fingers, 9 - superficial flexor of the fingers, 10 - ulnar muscle, 17 - brachial m., 18 - radial extensor of the wrist, 21 - interosseous muscle, 21 / - its tendon to the common extensor of the fingers.

Before starting the article, it is necessary to separate two concepts: the shoulder and the shoulder joint. The shoulder is the area of ​​the arm from the elbow to armpit, and the shoulder joint is the articulation of the bones with which the arm is attached to the body. The shoulder joint has a unique structure. This article is devoted to the features of this articulation.

Bones

The structure of the shoulder joint (articulatio humeri) is quite complex. The articulation itself consists of the humerus and scapula. The bone ends with a round head, which is located in the scapular cavity. Such a connection is called a ball joint.

The junction of the humerus and scapula is enclosed in a joint capsule. The surface of the head and the scapular cavity are lined with cartilaginous tissue, which ensures unhindered sliding. Inside the joint capsule is synovial fluid, which nourishes the cartilage tissue and prevents it from being erased.

It should be noted that the head of the humerus is almost 3 times larger than the scapular cavity. This results in excellent mobility in all directions. The scapular bone remains practically motionless, and all movements are carried out by the bone of the upper limb. In addition to the two main bones, the shoulder joint includes the clavicle, which is involved in two joints: the acromioclavicular and sternoclavicular.

Ligament apparatus

The structure of the human shoulder joint involves not only bone components. Around each joint are ligaments and tendons. They are necessary in order to limit movement, thereby preventing dislocations and other injuries.

Since the shoulder “hinge” has many degrees of freedom (that is, it can rotate in several directions), there are also many ligaments surrounding this joint. There are 6 large ligaments in the joint of the shoulder, and there are also tendons. The tendon-ligamentous conglomerate maintains the connection in proper condition, protecting it from injury.

muscles

Several large muscles and many small ones are attached to the joint of the shoulder. IN muscular framework includes some muscles of the back, upper limb and neck. Around the joint are the following muscles:

In addition to the three muscles that protect the joint, there are muscles that form the rotator cuff. These are 4 muscles that provide a wide range of motion of the upper limb in any direction.

These include: subscapular, infraspinatus, supraspinatus, small round. If you carefully delve into the detailed structure of the shoulder joint, it turns out that it consists of many moving elements. How can they move among themselves without interfering with each other? This is helped by synovial bags located between the components of the shoulder. They are filled with synovial fluid that reduces friction. The number of bags for each person is different, but the largest ones are always present: subscapular, subcork-shaped, intertubercular, subdeltoid.

Functioning

The anatomical structure of the shoulder joint allows you to perform many functions. There are 3 axes of joint movement: vertical, sagittal and frontal. Movement around the frontal axis is flexion and extension of the joint. Outward and inward movements are carried out along the vertical axis. And along the sagittal axis, the joint is abducted and adducted. Due to the many degrees of freedom, the shoulder connection becomes fragile and very easy to damage under improper loading.

Pathologies

There are many diseases of the shoulder belt. Below are the most common:

This was a list of the most common injuries and diseases, but there are other pathologies that are less common.

Shoulder Anatomy, Shoulder Anatomy

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The shoulder joint is a rather complex mechanism, thanks to which we can carry out various movements. Due to the peculiarities of its device, the shoulder joint is quite vulnerable and prone to various injuries. Let's take a closer look at what the human shoulder joint is.

Shoulder girdle:

  • shoulder blade
  • Collarbone
  • Brachial bone

The deltoid muscle, which will be discussed below, is attached with the help of tendons to the skeleton, thanks to the bones, the names of which were announced in the list above. A wide range of arm movement is achieved precisely thanks to this muscle.

The shoulder joint consists of layers:

  • Bone - has the deepest layer
  • Nerves
  • Vessels
  • Tendons
  • Bundles
  • muscles
  • Skin covering

Due to the nerves, special signals are transmitted that go from the brain to the muscles, thus ensuring the process of moving the shoulder joint, and only then, the nerves transmit the signal back to the brain, reporting pain, pressure, and other factors affecting the muscles . If you roughly imagine how the shoulder works, you can distinguish it as a ball joint, in which the ball itself is represented by the head of the humerus. A little higher is the acromion region - the upper part of the shoulder joint, and next to it is the acromion - clavicular joint.

  • Brachial
  • Acromial-clavicular
  • Sterno-clavicular

Deltoid muscle device:

  • Front beam - allows you to bend the shoulder and turn it inward. Raises his outstretched hand
  • Medium beam - allows you to take your hand back
  • Posterior bundle - allows you to perform extension of the shoulder and turns it outward. Raised hand lowers down

The deltoid muscle has a triangular shape, and it is also quite thick. It covers our shoulder joint, and some of the shoulder muscles. The bundles of this muscle converge to the top of the triangle, as if fan-shaped, and are directed downward. The deltoid muscles tend to contract both in individual bundles and as a whole, while developing impressive strength.

Deltoids are a type of feathery muscle. This condition allows you to more productively generate efforts and contribute to better stabilization, however, there is a small minus - a certain amount of flexibility is lost.

Other muscles of the shoulder girdle:

  • teres major and minor muscles
  • supraspinatus muscle
  • infraspinatus muscle
  • Subscapularis

The rotator cuff of the shoulder acts as the primary and important stabilizer during shoulder movement. Its strength ensures the stability of our entire shoulder joint, reducing the possibility of various injuries during physical activity with weight. Consists of the four muscles indicated in the figure above, which take part in the rotational movements of the shoulders. It is worth paying attention to the fact that, before starting a workout, it is necessary to pay due attention to warming up and warming up the rotator cuff of the shoulder in order to avoid injuries.

Shoulder joint:

In our body, the shoulder joint has the greatest mobility. With it, we can rotate our arms in various positions. Agree that it is freedom of movement that provides us with a feeling of the fullness of life.

In the shoulder joint, a special classification of tissues can be distinguished, which are referred to as "soft". These tissues are responsible for joint mobility and also stabilize the joint. Soft tissues are very vulnerable and often subject to wear and tear, causing injury to the shoulder joint.

Soft tissues include:

  • joint capsule
  • Shoulder ligaments
  • Upper articular lip
  • Long head of biceps tendon
  • Rotator cuff
  • Bursa

The head of the humerus performs a very important function - it is responsible for maintaining the stability of the entire joint, and it is located in the very center of the articular capsule. The humerus is held in position by ligaments, tendons, and anterior muscles.

Acromio-clavicular joint:

Its function is to allow the hand to connect with the chest area. According to their specificity, the acromio-clavicular ligaments act as an important horizontal stabilizer. In turn, the coracoid-clavicular ligaments act as a vertical stabilizer of the clavicle. The largest number of rotations occurs precisely in the clavicle, and only 10% of rotations occur at the junctions of the acromio-clavicular joint itself.

The sternoclavicular joint:

This joint allows us to raise our arms up, bring them over our heads, and it also allows us to perform rotational movements in the shoulders. If there is an injury to this joint, or a disease, the movements in the shoulder joint become limited, and full use becomes impossible.

If we talk about the progress of the muscles of the shoulder joint in sports, then, perhaps, the deltoid muscle is the best subject to development and growth. For a more significant result, experts recommend training all 3 bundles of the deltoid muscle.

Exercise examples:

These are not all types of exercises that develop the deltoid muscle. In the Exercises section, we will look at more types of exercises for the deltoid muscles.

Shoulder joint anatomy video:

I suggest you familiarize yourself with the anatomy of the muscles of the back

Shoulder muscle anatomy. We swing correctly.

My respects to the honest fraternity of the ABC of Bodybuilding project! Today we have nudity on the agenda - this is how I described the new series of articles on the anatomy of muscle groups, which will now be published on Sundays. In it, we will not reveal any secret chips, but we will try to examine in as much detail as possible, without water, all the “muscular insides” and the kinesiology of movements. Today on the agenda is the anatomy of the muscles of the shoulders.

So, sit down, my dear, let's start gesturing.

Anatomy of the muscles of the shoulders: what, why and why?

To be honest, I put off writing such notes until the last, and all because they give away too much theory and little practice in them, and readers rarely like such publications, because they give them bread and circuses :). However, on the other hand, no self-respecting project simply can exist without such a theoretical section, because this is its foundation, the backbone on which it must stand. Therefore, I will try to cover anatomical issues as painlessly and boringly as possible, and I am sure this cycle will become your favorite on the project.

Why are such articles important? Well, firstly, they allow the athlete to meaningfully approach the exercises with a full understanding of the essence of all ongoing processes. This eliminates the possibility of thoughtless pulling of the glands. Secondly, it is always useful to keep the correct movement mechanics in mind and scroll through them as the exercise progresses. Well, and thirdly, to show off your mind in front of your colleagues in the hall is also worth a lot. Actually, stop pouring water, let's get to the point.

Shoulders (deltas) are the most mobile joint of the human body, with the widest and most varied range of motion. The shoulder joint is the most unstable articular joint, and therefore it is easy to dislodge and damage it. It is more correct to talk about the shoulder in the context of not one joint, but complex complex bones, ligaments, muscles and tendons called the shoulder girdle. The main function of the latter is to provide strength and range of motion to the hands.

The deltoid muscles are named after the Greek letter delta for its triangular shape.

The shoulder girdle consists of three bones:

  • shoulder blades (scapula);
  • clavicle (clavicle);
  • humerus (humerus).

The deltoid muscle is attached by tendons to the skeleton with the help of the three bones mentioned above, and its contraction leads to a wide range of arm movement.

In the context of the shoulder joint (delta) consists of layers:

  • bone is the deepest layer;
  • nerves and blood vessels;
  • tendons, ligaments and muscles;
  • skin covering.

Nerves carry (in one direction) signals from the brain to the muscles to move the shoulder and (in the opposite direction) carry signals from the muscles to the brain about pain, pressure exerted on them, and so on.

The shoulder itself is a ball joint, the ball of which is the head of the humerus. Above the “ball” is the acromion ( top part shoulder). Next to them is the acromioclavicular joint.

In total there are three joints of the shoulder girdle:

  1. shoulder joint (GH) - connects the humerus (arm) with chest(breast) . The most important and formative of the joints.
  2. acromioclavicular (AC) ;
  3. sternoclavicular (SC).

The roundness that we see on our shoulder (or do not see yet :)) consists of 3 individual muscles/heads:

  • front (anterior delt);
  • middle (medial delt);
  • back (posterior delt).

The deltoid muscles are feathery (attached at an angle to the tendons), which contributes to better power generation and stabilization, but there is a certain loss in flexibility.

Anatomy of the muscles of the shoulders: features of the joints

No. 1. shoulder joint

The most mobile joint, providing most of the movements of the shoulder girdle. It allows you to move your arm forward/backward, from side to side to rotate it in and out, move it along the body from front to back, counterclockwise and clockwise rotation. All of the above is shown in the figure.

Despite such an extensive range of motion, there are certain positions in which the shoulder joints feel uncomfortable, in particular, these include lowering the arms behind the head (for example, lowering the barbell behind the head).

The shoulder joint has a separate class of tissues called soft tissues that keep it stable and provide mobility. These soft tissues are most exposed to wear (their structures become thinner, the lubrication of the synovial fluid is consumed, which allows the articular cartilage to slide) and are the first to fail, leading to a shoulder injury.

Soft tissues include:

  • joint capsule;
  • shoulder ligaments;
  • upper articular lip - increases the depth of the articular bag by 50% ;
  • long head of the biceps tendon;
  • rotator cuff of the shoulder (rotator cuff muscles);
  • bursa - a small sac of lubricating fluid that protects the tendons of the rotator cuff.

The stability of the joint depends on the preservation of the head of the humerus, located in the center of the articular capsule. The humerus itself is held in place by ligaments, tendons, and anterior muscles (mainly the rotator cuff).

In general, it is worth saying that many athletes do not pay any attention to training the muscles of the rotator cuff, and in fact the stability of the entire shoulder joint and, as a result, the likelihood of injury while working with weights depends on its strength. The rotator cuff is the primary stabilizer during shoulder movement. Four of its muscles are involved in all rotational and overhead movements of the shoulders. Therefore, it is critically important before training delts to warm up the rotator cuff using the following exercises.

No. 2. acromioclavicular joint

Helps connect the arm to the chest area. The acromioclavicular ligaments (superior AC) are the most important horizontal stabilizer. The coracoclavicular ligament helps in vertical stabilization of the clavicle. A significant part of the rotation occurs in the clavicle and around 10% at the junction of the acromioclavicular joint.

No. 3. sternoclavicular joint

Most of the rotation occurs at the SC joint, and its stability depends on the soft tissues. The posterior sternoclavicular joint capsule is the most important structure to prevent forward and backward displacement of the medial clavicle.

Now let's move on to…

Shoulder muscle anatomy: what you need to know to build huge shoulders

I fit the whole theory into a capacious visual drawing, so let's stare :).

There is a clear division at the shoulders muscle fibers, and therefore, to give them a spherical shape, it is necessary to work out all three beams per workout.

Well, actually, that's all according to theory, now let's summarize all this information and draw the appropriate conclusions.

Delta FAQ

  • shoulders are a very mobile joint, they are directly and indirectly involved in many movements (for example, bench press);
  • beginners should not train deltas anymore 1 once a week (provided that there are only three workouts a week);
  • the most appropriate training strategy is to work out each beam 1-2 exercises;
  • it is best to start training with a lagging bundle of deltas, most often it is the back one;
  • shoulders require a good warm-up, so take 3-5 minutes to carry out the relevant work;
  • always try to include exercises to strengthen the rotator cuff in your delt workout, and it is better to start with them.

I have everything on the sim, it remains to wait.

Afterword

Today we mastered a theoretical note called "Anatomy of the muscles of the shoulders." I would like to remind you that although the article looks unprepossessing, it is archival and archival, because it will help you to approach the choice of exercises and their implementation much more thoughtfully.

So, in this spirit, in this section, see you soon!

PS. Friends, our project is included in the ranking of the best BB and fitness sites. Vote for the ABC of Bodybuilding, we deserve to be more!

P.P.S. Did the project help? Then leave a link to it in the status of your social network- plus 100 points to karma, guaranteed.

With respect and gratitude, Dmitry Protasov.

Shoulder joint

In the body, the shoulder joint is the most mobile joint of bones, providing a variety of movements. Human hands move in all directions and planes, while in animals its movements are limited by some anatomical features. To diagnose diseases, X-rays and MRIs are prescribed.

The structure of the shoulder and its topography

The joint occupies part of the upper thoracic limb. In a physically healthy person, the shoulder joint is not visible, because it is hidden by muscles. The area of ​​the scapula has the form of an elongated triangle. The outer surface of the human scapula has an awn that divides it into two parts. It is palpable in the scapular region and looks like a dense cord.

Topographic anatomy examines in depth the topic of the location of certain organs in the body.

Joint anatomy

According to the anatomical structure, the shoulder joint is simple: it consists of two bones, while in a complex structure, menisci and additional bones lie between the bones. In terms of movement, it belongs to multi-axis, so any motor axis is subject to it. The head of the humerus is like a ball, so the type is spherical.

Joint bones

The scapula, humerus, arches of muscles, many ligaments, muscle and tendon elements participate in the formation of the shoulder joint. Shoulder - flat bone triangular shape. On the dorsal side, it has a scapular cartilage lining the upper fornix. The medial part of the human scapula contains the articular cavity. The head of the shoulder bone is located in it, but their surfaces are not congruent - a property when the bone surfaces that form the joint do not coincide in shape with each other. The scapular bone is connected to the humerus by the muscles of the shoulder and forearm.

Near the head is a large tubercle of the humerus (it, like the transverse olecranon, limits the range of motion). Around the glenoid cavity is the lip of the joint, it strengthens the head of the shoulder. Its direct function is immobilization, but with strong jerks, even it is not able to protect the joint from dislocation. In humans, the scapula occupies a dorsal position, while in animals it is located on the sides of the body. This structure of the shoulder joint was formed in connection with walking on two legs. Its anatomical characteristics also differ from the human.

Periarticular tissues

In the formation of the shoulder joint, in addition to bones, various tissues play a role. Such tissues are called periarticular. They perform an auxiliary (supporting) function. These include the joint capsule, the lip of the joint, and many ligaments. They are very different in structure and function, but their goal is the same - to minimize the risk of injury and provide room for movement.

Shoulder ligaments

The ligaments of the shoulder girdle are the main component of the joint, in addition to the muscles. Thanks to them, it is tightly fixed to each other, while giving the bones mobility. A special place among the ligaments is occupied by the arch of the shoulder, which connects the processes of the bones. They are strong and tight, it is this property that is the main factor in their ruptures, since the lack of extensibility causes damage. Main weak spots ligaments - this is the impossibility of committing sudden movements and greater stress on the joint. Ligaments have corresponding Latin names.

Joint muscles

The muscles of the shoulder joint are the main structural component that provides mobility. The functions of the muscles of the humeroscapular joint are diverse: flexion, extension, rotation, abduction - these features of the movement are explained by the fact that the joint is multiaxial. The peculiar structure of the shoulder and muscles cause an abundance of movements:

  • Flexion provide deltoid muscles. A special role is given to the brachioradialis.
  • Adduction - chest and biceps shoulder.
  • The rotation function is provided by a round one.
  • The longissimus and brachialis muscles are involved in extension.
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