Shoulder flexion and extension. Shoulder muscles. Movements of the shoulder girdle in the horizontal plane

60. Muscles that abduct and adduct the shoulder.

Shoulder abducted: deltoid muscle, supraspinatus muscle.

Deltoid

Supraspinatus muscle It starts from the supraspinatus fossa of the scapula and the fascia covering it, and is attached to the greater tubercle of the humerus and partly to the capsule of the shoulder joint. The function of the muscle is to abduct the shoulder and tighten the joint capsule of the shoulder joint.

Lead shoulder: large pectoral muscle, latissimus muscle back, subscapularis, infraspinatus.

Pectoralis major muscle

Latissimus dorsi muscle

Subscapularis muscle

Infraspinatus muscle

61. Muscles that supinate and pronate the shoulder.

Rotate the shoulder outward: deltoid muscle (posterior bundles), teres major muscle, infraspinatus muscle.

Deltoid starts from the clavicle (anterior part of the muscle), acromion (middle part) and the spine of the scapula ( rear end), and is attached to the deltoid tuberosity of the humerus. If the front and back parts alternately work, then movement occurs. upper limb forward and backward, i.e. flexion and extension. If the entire muscle tenses, then its front and back parts form a resultant force, the direction of which coincides with the direction of the fibers of the middle part of the muscle, helping to abduct the shoulder to a horizontal level.

Teres major muscle starts from the lower angle of the scapula and is attached to the crest of the lesser tubercle of the humerus, often by one tendon from the latissimus dorsi muscle. When contracting, the teres major muscle acts as a rounded eminence when the pronated shoulder is adducted. The function of the muscle is to adduct, pronate and extend the humerus.

Infraspinatus muscle starts from the infraspinatus fossa of the scapula. In addition, the origin of this muscle is the infraspinatus fascia. Attaches to the greater tubercle of the humerus. The function of the infraspinatus muscle is to adduct, supinate and extend the shoulder in shoulder joint.

Rotate the shoulder inward: deltoid muscle (anterior bundles), pectoralis major muscle, latissimus dorsi muscle, teres major muscle, subscapularis muscle.

Deltoid

Pectoralis major muscle starts from the medial half of the clavicle (clavicular part), the anterior surface of the sternum and the cartilaginous parts of the upper five or six ribs (sternocostal part), the anterior wall of the rectus sheath (ventral part) and is attached to the crest of the greater tubercle of the humerus. It refers to the muscles that extend from the trunk to the free upper limb. This muscle pulls the scapula forward and away from the spinal column. But this function is secondary. Basically, it is involved in the movements of the humerus. If the torso is fixed, then this muscle adducts, pronates and flexes the humerus.

Latissimus dorsi muscle starts from the spinous processes of the lower five to six thoracic vertebrae, all lumbar, upper sacral vertebrae and from the posterior part of the iliac crest, with four teeth from the four lower ribs, attaches to the crest of the lesser tubercle of the humerus. By adducting and penetrating the humerus, it causes the lowering of the upper limb girdle and adduction of the scapula to the spinal column; that part of the muscle that originates from the ribs can elevate them and have some effect on increasing volume chest when inhaling.

Teres major muscle

Subscapularis muscle located on the anterior surface of the scapula, filling the subscapular fossa, from which it begins. The muscle is attached to the lesser tubercle of the humerus. It produces shoulder adduction; acting in isolation, it is its pronator.

It happens that after a load or for no reason, the shoulder suddenly “shoots”, as people say. It’s impossible to raise your hand, let alone move it. Due to severe pain, many are unable to perform official duties or lead a normal lifestyle. Or your shoulder is just aching and you don’t know why. To find out what it is and start treating it faster, you need to immediately contact a specialist, because the cause of pain may be periarthritis.

Shoulder periarthritis is an inflammatory process in the tendons of the joint and capsule, while the articulation and cartilage tissue are not affected.

How does the treatment work?

For effective treatment the cause of the disease must be eliminated. Here are some reasons and one possible solution:
- displacement of the vertebrae - manual therapy;
- blood circulation in the shoulder joint is impaired - angioprotective agents.
– liver disease – diet and medications to restore liver function, etc.
Also, at different stages of periarthritis of the shoulder joint, treatment differs.

They are divided into 3 stages:
Stage 1 – simple form(“painful shoulder”) It is characterized by mild pain in the shoulder joint when moving, but does not bother you at rest;

Stage 2 – acute form. Severe pain both at rest and when moving. The temperature may rise to 37.5 degrees, and markers of the inflammatory process appear in urine tests. During this period, it is necessary to immobilize the shoulder joint, make a garter, and do not place any load on the joint.

Stage 3 – chronic form (“frozen shoulder”, “blocked shoulder”). The pain becomes tolerable and intensifies at night or towards morning. Sometimes at this stage the disease goes away on its own. Or it can develop into ankylosing periarthritis. The shoulder joint becomes fused, interfering with the normal functioning of the arm.

Comprehensive treatment will help defeat periarthritis faster. And return healthy image life.

Conservative treatment.

For a sore shoulder, non-steroidal anti-inflammatory drugs (diclofenac, butadione, Celebrex, etc.) are prescribed to relieve inflammation and pain. With stage 1, sometimes this is enough for complete recovery. But these drugs must be taken very carefully, they irritate the gastric mucosa; in case of ulcers and other diseases of the gastrointestinal tract, consultation with a doctor is necessary.
Compresses with dimexide or bischofite also help cure the disease. But during exacerbation, bischofite is contraindicated.

It happens that anti-inflammatory drugs do not help, then the attending physician may prescribe treatment hormonal drugs(flosterone, diprospan).
Usually, they are prescribed in the form of injections that are injected into the muscles of the sore shoulder. This medicine is very strong, so the duration of the course is short: 2-3 injections.

If, within 15-20 days, no other actions have led to an improvement in the patient’s condition, periarticular novocaine blockades are placed.
Novocaine is injected into the affected tissue at certain intervals, sometimes together with a glucocorticoid agent. This procedure is done to relieve pain that makes movement impossible.

Over the course of a month, the procedure can be repeated 1-3 more times.

Physiotherapy.

The patient is referred to physical therapy in order to restore full motor function of the shoulder, eliminate inflammation and muscle spasms.
Ultrasound – relieves pain, relieves spasms, improves blood circulation.
Shock wave therapy - infrasound waves, penetrating, create pulse vibration. Which helps improve blood flow and tissue regeneration.
Magnetic therapy – activates immune system, restoration of affected tissues, pain relief.
Hirudotherapy is medicinal leeches that are placed on the sore shoulder. It is almost painless and very effective method help yourself get better. By-effect: an allergic reaction may occur, if it intensifies, this procedure is simply cancelled.

Physiotherapy.

Properly selected exercises will not only do no harm, but will also help you recover. Everything needs to be done slowly, without sudden movements, gradually increasing the load. If the pain is severe, it is recommended to stop exercising; also, during an exacerbation, you should not engage in physical exercise.

A few exercises:

1. Clasp your hands in a “lock” in front of you and slowly raise up and lower down.
2. Flexion and extension of the arms at the elbow joint.
3. With our sore hand we slowly try to “draw” a circle in the air, the more we get, the better.
4. We make a “lock” behind our back, try not to bend our arms.
5. Throw the ball into an imaginary ring.
6. We press the ball to the chest, the elbows are moved to the sides as much as possible without painful syndrome, then we slowly straighten it, as if pushing the ball away from ourselves, forward.
7. Kick the ball on the floor with your sore hand.
   Exercises are done regularly, without overloading the diseased ligaments.

Diet.

There is no need to follow a special diet. The main thing is to eat right and consume enough vitamins, proteins, and minerals so that during periarthritis, the tissues of the shoulder joint receive sufficient nutrition.

Traditional treatment.

There are many recipes in the folk treasury that help with various ailments. How to treat shoulder periarthritis can answer ethnoscience, but only in the first stages of the disease or as an additional treatment, after consulting a doctor.

If the symptoms of periarthritis of the shoulder joint last more than a week, during treatment folk remedies, you must immediately consult a doctor.

We can offer you some recipes from traditional medicine:

1. An infusion (tea) is made from yarrow, St. John's wort, rose hips, lingonberry leaves and currants (black).
2. Compresses and rubs that warm the sore joint.
3. Apply honey to the sore spot, wrap it up and leave it overnight.
4. Apply burdock or cabbage leaves to the sore spot and hold for as long as possible, first fixing it.

Tibetan medicine.

For the treatment of shoulder periarthritis, the following is used:

• acupuncture – relieves pain, removes inflammation;
• acupressure – relieving spasms, improving blood flow;
• manual therapy - relieves joints, thus helping recovery;
• warming up with wormwood cigars along with Tibetan infusions.

All treatment occurs in a complex, which helps speedy recovery. The technique is also selected individually for each patient.

Surgical intervention.

Surgery, subacromial decompression, is done if other treatments have failed. The pain remains, but motor activity decreases.
During surgery, the acromion and one ligament in the same place are removed. Motor functions return completely or to a greater extent than before.

Remember, this is important!
Periarthritis of the shoulder joint - for a speedy recovery, it is necessary to treat it comprehensively: with medications, physiotherapy and physical therapy.
Contact a doctor at the first symptoms of the disease, do not let the disease progress and do not self-medicate.
If treatment within 5-6 weeks does not produce results, surgery should be performed.

In order to understand how the shoulder works, it is necessary to understand what mechanisms and elements are involved in this process. The shoulder joint has a complex structure and is part of shoulder girdle.

The scientific definition of the concept of “shoulder” does not coincide with the everyday understanding of the meaning of this term. From an anatomical point of view, this part of the body includes only a segment of the arm from the shoulder joint to the elbow. What we call a shoulder in everyday life is scientifically called the shoulder girdle. Thanks to its unique structure, it allows you to perform hand movements in all planes.

Structure

The shoulder joint is located at the top of the arm. It is closest to the body and is the largest part of the upper limb. It consists of:

• Articular surface on the scapula.
• The humerus, which is surrounded by longitudinal muscles.
• Connective tissue.
• Subcutaneous fatty tissue.
• Skin.
• Synovial lip.
• The elastic capsule that contains the shoulder joint.
• Ligaments and a thick layer of muscle that strengthen the shoulder.

Communication with the central nervous system is carried out through the axillary nerve, as well as branches of the long thoracic, radial and subscapular nerves.

Movements in the shoulder joint can be carried out by a person in all planes. Thanks to the special mobility of this joint, you can freely raise your arms, place them behind your head and back. The unusual anatomy of the shoulder joint causes instability and a high risk of injury.

Functions

The high mobility of the shoulder is due to the effective work of not only its articulation. The entire necessary range of motion is available thanks to the combined work of all joints of the arms and shoulder girdle. There are three axes of movement of this joint:

1. Front axis. Responsible for the function of flexion and extension.
2. Sagittal axis. Involved when abducting the arms.
3. Vertical axis. Organizes rotation.

The shoulder joint itself is capable of providing mobility of the upper limbs only up to the shoulder line. To perform certain movements, different segments are connected to the work:

1. In order to raise or lower your arms, as well as place them behind your back, flexion or extension is carried out. The shoulder joint only works up to the horizontal axis. Next, the collarbone and scapula are involved in the work.
2. When performing movements reminiscent of flapping wings, after the joint brings the limbs to shoulder level, the shoulder blades and spinal column are included in the work. Thus, the arms rise to a vertical axis.
3. The shoulder shrug requires the simultaneous use of the shoulder joints, collarbones and shoulder blades.
4. Rotational movements of the arms around three main axes are performed through the interaction of the upper limbs, shoulder blades and collarbones.

Bones

The shoulder joint is formed by the connection of the upper part of the humerus bone (the head) to the shoulder blade. Otherwise, it is called spherical due to its rounded head. Its shape exactly matches the contours of the articular surface. The junction is called the glenoid cavity. At this point, the humerus and scapula form a joint. The humerus is held in the joint by a cartilaginous plate. It is formed along the edges of the glenoid cavity and completely repeats its shape, covering the head of the tubular bone.

The structure of the shoulder joint has two interesting features:

1. The size of the spherical head is several times greater than the volume of the scapular cavity.
2. The joint capsule connecting the shoulder bone and scapula does not have additional cartilage, septa or discs.

The collarbone plays an important role. Effective functioning of the shoulder joint is impossible without this small tubular bone.

Periarticular tissues

The shoulder joint is surrounded by three main structures - the cartilage plate, the joint capsule and ligaments. All these tissues differ in their structure, origin and main functions. But thanks to their interaction, a person’s upper limbs are quite mobile. In addition, periarticular tissues perform a protective function, reducing the risk of possible damage.

The cartilage plate smoothes out the difference in size between the head of the humerus and the glenoid cavity. It softens minor shocks and impacts, but its safety margin may not be enough under severe physical impact.

Joint capsule

The head of the human ball and socket joint retains its correct position due to the ligament system of the shoulder articulation. This strong connective tissue fuses with the thin joint capsule. The thickness of its surface is non-uniform. The densest layer is on the outer surface of the shell. It includes the coracohumeral ligament. Starting from the coracoid process, it spreads over the head of the bone of the same name and is attached to outside. Performs a holding function, preventing excessive extension of the joint on the outside of the shoulder. Is different high level strength.

Other areas of the articulation strengthen the less developed articular-humeral ligaments (formed by the upper, middle and lower bundles). Despite the fact that they play a less important role in the functioning of the joint, characteristic thickenings are present in the places where they are dislocated. The segments of the joint capsule located between the ligaments are thinner and weaker.

Joint capsules

Normal sliding of the tendons of the shoulder joint is ensured by the synovial bursae located in the surrounding tissues. They are cavities filled with intra-articular fluid. The number of bags, their structure and shape depends on the individual characteristics of each person:

1. The most common is the subscapularis joint capsule. It is located in the area between the subclavian and deltoid regions or in the area of ​​the neck of the scapula.
2. Slightly higher, between the coracoid process and the tendon of the subscapularis muscle, a subcoracoid bursa is formed.
3. The largest bag (its dimensions coincide with the palm of a person) is called subdeltoid. Located on the outside of the shoulder joint, in the area deltoid muscle. Represents one large or a large number of small formations.

The joint capsules ensure smooth movements and protect the joint membrane from stretching.

Muscle structure

Normal mobility of the joint is ensured by the articular capsule and the ligament system around it, and the main strengthening and motor role is played by the shoulder muscles. Muscle tissue and tendons form a strong and elastic holding frame.

The following muscles surround the shoulder joint:

1. The deltoid muscle covers the joint from the outside and from above. It does not have a direct connection with the joint capsule, but at the same time protects the joint on three sides. The deltoid muscle unites three bones at once - the shoulder, scapula and collarbone.
2. On the front side, the joint is covered by the biceps muscle (biceps). At one end it is attached to the scapula, passes through the joint and goes inside the shell into the intertubercular groove to the humerus.
3. WITH inside joint located triceps ( triceps). It consists of three parts - the long, literal and medial head. Responsible for moving the arm back and participating in extension of the forearm.
4. On the inside, under the head of the biceps, the joint is protected by the coracoid muscle. She is responsible for flexing the shoulder and participates in raising the arm up.

Basically, the muscles strengthen the human shoulder joint from the outside, while the inner and lower parts are practically not protected. Most injuries are related to this.

Development

During the formation of the fetus in the womb, the bones of the shoulder joint are separated. After birth, his shoulder development goes through several stages:

• When a child is born, the rounded head of the spherical joint is almost completely formed, the articular cavity is underdeveloped, and the cartilaginous plate is not fully developed.
• Throughout the first year of a child’s life, the shoulder joint is in the process of strengthening. The joint capsule contracts, thickens and fuses with the coracobrachial ligament. As a result of this process, joint mobility and the risk of injury are reduced.
• Over the next two years, the segments of the shoulder joint significantly increase in size and take on their final shape. Overgrown bones stretch ligaments and joint capsules. Mobility becomes maximum.

The head of the humerus bone is the least susceptible to metamorphosis. During the formation process, it only slightly changes its shape. The head reaches its maximum size closer to puberty.

Blood supply

The main sources of blood flow to the shoulder are the main axillary artery. It crosses the depression of the same name and goes into the brachialis muscle. The removal of metabolic products is carried out through the brachial and axillary veins. An auxiliary role is assigned to the scapular and acromial-deltoid vascular circles. They form a dense network of vessels deep in the deltoid and subscapularis muscles.

The special arrangement of the auxiliary circles allows direct blood supply to the brachial artery in case of disruption of the main blood flow.

Pathology

Most often, shoulder diseases are associated with injuries - dislocations, damage to muscles and ligaments. This is due to the special structure of the joint. Most often, pathologies develop as a result of traumatic factors such as:

• Sudden movements of the upper limbs.
• Incorrect physical exercise, lifting weights.
• Falls and bruises of the shoulder joint.
• Poor circulation in the ligament area.

Therapy in such cases is conservative in nature - immobilization (wearing orthoses), physiotherapy. Surgical intervention is allowed only in case of old injuries.

There are a number of diseases that can cause shoulder pain. These include arthrosis of the acromioclavicular joint, arthritis; osteochondrosis, neuritis, plexitis, etc. Therefore, it is very important to immediately consult a doctor if pain occurs.

The anatomy of the human shoulder is unique and has its own weak sides. Therefore, it is very important that all its segments interact accurately and harmoniously. Only in this case will the joint effectively cope with its functions.

Shoulder joint: structure and functions

The shoulder joint is one of the largest joints in the human musculoskeletal system. Its spherical design, as well as its equipment with powerful muscular and ligamentous apparatus, make it at the same time very strong, but also vulnerable.

Vulnerability lies in the enormous stress to which it is exposed throughout a person’s life. We can say that the shoulder joint is the source from which all the most important movements originate - from the usual ability to hold a glass of water in one’s hand, to the most high achievements in the professional sports arena.

Other structures of the shoulder joint

Having become more familiar with the structure of the joint and its features, you can easily understand how much it needs to be treated with care.

Functions of the shoulder joint

First of all, it should be clarified: shoulder and shoulder joint (words that in everyday speech have acquired the status of synonyms) are completely different concepts. The shoulder joint is the connection between the articular surface of the scapula and the articular head of the humerus. Actually, the shoulder originates from the shoulder joint - a tubular bone, which at one end is attached to the shoulder joint, and at the other to the elbow.

The main function of the shoulder joint is to stabilize the movements of the upper limbs while increasing the amplitude of their movements.

Simply put, the biomechanics of the shoulder joint allows you to move your arms in several projections at a wide angle and at the same time ensure a strong attachment of the freely movable element (shoulder) to the conditionally movable element (scapula).

Thanks to the structure of the shoulder joint, a person is able to perform arm movements in a wide range: adduction and abduction of the arms, flexion and extension, rotation.

In addition, the listed movements can be “subtle” - with a deviation from the conventional axis within a few degrees, up to a rotation close to 360 degrees, and also aimed at the accuracy of movements or their strength. All this becomes possible due to the complex structure of the shoulder joint, the design of which includes a variety of “mounting elements”.

Features of the structure of the shoulder joint

Perhaps the most “unpleasant” difference between the shoulder joint and other joints of the body is the discrepancy between the sizes of its structures.

The depression in the shoulder blade into which the head of the humerus is inserted resembles a flat saucer. The diameter of this “saucer” is significantly smaller than the diameter of the articular head of the humerus. Visually this can be represented as big ball, lying on a small plate, and ready to fall off it at any moment.

On the one hand, this feature guarantees a free range of motion in the shoulder joint. On the other hand, too flick or a movement accompanied by the use of force (a pull on the arm, a fall with an impact on the shoulder joint, etc.) can lead to the loss of the humeral head from the joint.

And although the head is surrounded by an elastic cuff that serves as a kind of limiter, shoulder dislocations are a very common injury. With a dislocation with significant displacement of structures, even ruptures of ligaments and muscles are possible.

Bony structures of the shoulder joint

As already mentioned, the shoulder joint is formed by two main bone elements: the head of the humerus bone and the articular part of the scapula. The main part of the movements in this joint is ensured by the mobility of the head in the recess of the scapula.

Since the shoulder joint accounts for the majority of all loads to which the shoulder girdle is exposed, it is not surprising that wear and tear on its bone structures and inflammation in them are quite common.

Most frequent illnesses, affecting the bone tissue of the joint are the following:

• traumatic – dislocations, subluxations, fractures of the humeral neck;
• congenital - dysplasia of the shoulder joint (underdevelopment of one or more bone structures or discrepancy in size relative to each other);
• degenerative – arthrosis of the shoulder joint, in which the cartilage and bone tissues become thinner, deformed, and the joint loses its motor functions. The disease most often develops against the background of age-related changes in the body, as well as with deterioration in the nutrition of joint tissues - conditions caused by metabolic disorders, frequent injuries, decreased intensity of blood supply to the shoulder joint;
• inflammatory – arthritis of the shoulder joint, developing against the background of injury or previous systemic infectious diseases. For arthritis in cartilage and underlying bone tissue An inflammatory process develops, which without treatment is dangerous due to its complications.

Ligamentous apparatus of the shoulder joint

Far from being the largest, but – without exaggeration – the most important components of the ligamentous apparatus are small muscles rotator cuff. This complex includes the supraspinatus, infraspinatus, teres minor and subscapularis muscles.

They serve as fixators to prevent damage and displacement of the head of the humerus during the work of the largest muscles of the shoulder girdle - deltoid, biceps, pectoral and dorsal.

The glenohumeral ligaments are made up of strong fibrous tissues that rigidly connect bone structures. Unfortunately, it is their strength and rigidity that is the main cause of ruptures: without the ability to significantly stretch, the ligaments can be damaged under significant loads.

From all of the above, you may get the impression that the shoulder joint is an extremely fragile structure. But this statement applies only in cases where a person neglects physical activity and playing sports, leads a sedentary lifestyle. The joints (not just the shoulders) of such people are characterized by insufficient blood supply, a deteriorated supply of nutrients, and therefore are subject to injury under any, even minor, loads.

With healthy activity, compliance with norms healthy eating and the mode of work and rest, the shoulder joint can be called one of the strongest and most resilient in the human body.

But excessive stress on the shoulder joint, especially if not alternated with proper rest, can trigger a condition known as joint fatigue. In this case, any factors can cause inflammation or damage to muscle tissue and tendons:

• periarthritis of the shoulder joint (inflammation of the tendons) is a common disease that develops in response to injury (fall, bruise) or excessive stress;
• A sprain follows any type of injury and can lead to significant loss of motor function in the upper extremity. If left untreated, an inflammatory process often develops and spreads to the tissue surrounding the ligament.

Blood and nerve network of the joint

Any disease or injury to the shoulder joint is accompanied by pain, which can rarely be described as “minor.” The pain can be so severe that even the simplest movements become impossible.

This is a safety mechanism due to the functions of the thoracic, radial, subscapular and axillary nerves, which ensure the conduction of signals through the shoulder joint.

Thanks to pain syndrome a damaged or diseased joint is forcibly “deactivated” (if the pain is severe, it is difficult to make any movements), which gives injured or inflamed tissues time to recover.

Important: pain in the shoulder joint can be caused by injuries or diseases of the cervical and thoracic spine, which requires immediate medical attention.

An extensive network of vessels is responsible for the blood supply, which transports nutrients and oxygen to the joint tissues, and, together with the blood, removes decay products. But two large arteries lie next to the shoulder joint, which makes injuries dangerous: with a significant displacement of the head or a comminuted fracture, there is a risk of compression or rupture of blood vessels.

Important: any shoulder injuries accompanied by numbness of the arm on the injured side and a general feeling of weakness (even in the absence of bleeding) need to see a doctor as soon as possible after the injury. These signs may indicate a circulatory disorder that requires qualified medical care.

Other structures

The design of the shoulder joint includes other structures whose health is critical to the ability to move:

• synovium - a thin layer of tissue lining the inner surface of the joint (except for areas covered with cartilage). This membrane, rich in blood vessels, serves as the main source of nutrition for cartilage and bone tissue. In addition, the shell releases a fluid that softens friction during movement and protects internal structures from wear. In case of injuries, as well as as a complication of arthritis and systemic infections, synovitis can develop - inflammation of the synovial membrane.
• periarticular bags perform two functions simultaneously. They facilitate the movement of all articular and periarticular elements and at the same time prevent their premature wear. These are small "pockets" located near the joint and filled with special liquid, which allows the periarticular structures not to “rub” against each other, but to slide. Inflammation of these bursae - bursitis - is a common occurrence with injuries (especially with infected skin wounds) and general infectious diseases.

By taking care of healthy activity, proper nutrition, proper rest, and also by consulting a doctor if there are any signs of trouble in the joint, you can extend its “life” and maintain a high quality of your own life for many years.

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Laboratory lesson

"Muscles of the upper limb"

Muscles producing movements of the upper limb belt

Schematically, the movements of the upper limb girdle (scapula and clavicle) are divided into:

1.Movement forward and backward with abduction of the scapula from the spinal column and adduction to it.

2. Raising and lowering the scapula and clavicle.

3.Movement of the scapula around the sagittal axis with the lower angle to the medial and lateral sides.

4. Circular movement of the lateral end of the clavicle and at the same time the scapula.

These movements involve six functional muscle groups.

Forward movement

The forward movement of the upper limb girdle is produced by muscles that cross the vertical axis of the sternoclavicular joint and are located in front of it. These include:

1) pectoralis major, acting on the girdle of the upper limb through the humerus;

2) pectoralis minor;

3) anterior dentate.

Moving backwards

They are carried out by the muscles that cross the vertical axis of the sternoclavicular joint and lie behind it. This muscle group includes:

1) trapezius muscle;

2) rhomboid muscle, major and minor;

3) latissimus dorsi muscle.

Upward movement

Raising the belt of the upper limb is performed by the following muscles:

1) upper beams trapezius muscle which pulls up the lateral end of the clavicle and the acromion of the scapula;

4) the levator scapulae muscle;

5) rhomboid muscles, during the decomposition of the resultant of which there is a certain component directed upward;

6) the sternocleidomastoid muscle, which, attaching one of its heads to the collarbone, pulls it, and, consequently, the scapula upward.

Moving Down

Lowering is facilitated by muscles that go from bottom to top, from the chest or spinal column to the bones of the upper limb girdle:

1) pectoralis minor muscle;

2) subclavian muscle;

3) lower bundles of the trapezius muscle;

4) lower teeth of the serratus anterior muscle.

In addition, the muscles that go from the torso to the shoulder, namely the pectoralis major muscle and the latissimus dorsi muscle, help lowering, mainly through their lower parts.

Rotation of the scapula (movement of the lower angle inward and outward)

Rotation of the scapula inward, with the lower angle to the spinal column, is produced by a pair of forces formed by:

1) pectoralis minor muscle

2) bottom rhomboid major muscle.

Rotation of the scapula outward, with the lower angle from the spinal column to the lateral side, occurs as a result of the action of a pair of forces generated by the upper and lower parts of the trapezius muscle.

This movement is supported by:

1) front serratus muscle with its lower and middle teeth;

2) teres major muscle with a fixed free upper limb.

Roundabout Circulation

The circular movement of the upper limb girdle occurs as a result of alternate contraction of all its muscles.

Muscles that produce movements in the shoulder joint

In the shoulder joint, movements are possible around three mutually perpendicular axes:

1) abduction and adduction around the anteroposterior axis;

2) flexion and extension around the transverse axis;

3) pronation and supination around the vertical axis;

4) Roundabout Circulation(circumduction).

These movements are provided by six functional muscle groups.

Shoulder abduction

The shoulder abductor muscles cross the sagittal axis of rotation in the shoulder joint and are located lateral to it. The humerus is abducted by the following muscles:

1) deltoid and

2) supraspinatus.

Shoulder adduction

Special muscles, which would cross the sagittal axis of the shoulder joint and are located medial to it, there is no, therefore, the adduction of the shoulder according to the rule of the parallelogram of forces is carried out with the simultaneous contraction of the muscles located in front (the pectoralis major muscle) and behind the shoulder joint (the latissimus and teres major). These muscles help:

1) infraspinatus;

2) small round;

3) subscapular;

4) long head of the triceps brachii muscle;

5) coracobrachial muscles.

Shoulder flexion

The shoulder flexor muscles cross the frontal (transverse) axis of the shoulder joint and are located in front of it.

Shoulder flexion (moving it forward) is produced by the following muscles:

1) deltoid, its anterior part;

2) pectoralis major;

3) coracobrachial;

4)biceps shoulder

Shoulder extension

The muscles that extend the shoulder (move it backward), like the shoulder flexors, cross the frontal axis of the shoulder joint, but are located behind it. Shoulder extension is produced by the following muscles:

1) deltoid posterior part;

2) latissimus dorsi muscle;

3) infraspinatus;

4) small round;

5) large round;

6) long head of the triceps brachii muscle.

Shoulder pronation

Pronation of the shoulder, i.e. turning inward, produced by muscles; which cross the vertical axis of the shoulder joint, attaching in front of it. These include:

1) subscapular;

2) pectoralis major;

3) deltoid, its anterior part;

4) latissimus dorsi muscle;

5) large round;

6) coracobrachial.

Shoulder supination

Supination, i.e. turning the shoulder outward is produced by muscles that, like the pronators, cross the vertical axis of the shoulder joint, but are located behind it:

1) back of the deltoid muscle

2) teres minor muscle

3) infraspinatus muscle

4) biceps brachii muscle

The arm muscles include the muscles of the forearm and shoulder. The shoulder muscles are divided into two categories: flexors, or the anterior muscle group, and extensors, the posterior group.

Anterior muscle group The shoulder is formed by three main muscles:

• coracobrachial;
• two-headed;
• brachial muscle.

Extensors in turn are represented by two muscles:

• elbow muscle;
• triceps brachii muscle.

Shoulder flexors

Coracobrachialis muscle (m.coracobrchialis)

Coraco- brachialis muscle belongs to the group of flexors. It originates from the top of the coracoid process, and its other end, passing into a flat tendon, is attached to the humerus, just below the crest of the lesser tubercle. It is attached approximately there.

Main functions: The coracobrachialis muscle is involved in flexion of the shoulder at the shoulder joint. It brings the shoulder toward the body and also rotates the shoulder outward during pronation. When the shoulder is fixed, the m.coracobrchialis pulls the scapula forward and downward.

Biceps - biceps brachii (m.biceps brachii)

As the name suggests, the biceps brachii muscle has two heads. One of these heads is long, the other is short. The long head starts from the supraglenoid tubercle of the scapula. The short head begins in the same place where the coracobrachialis muscle originates - at the coracoid process. Fusing at the level of the shoulder, both heads form a spindle-shaped muscle, which turns into a tendon, which is attached to the tuberosity of the radius.

Main functions: The biceps is involved in flexing the shoulder joint and flexing the forearm at the elbow. When the forearm is rotated inward, the biceps brachii muscle helps return it to its original position.

Brachial muscle (m.brachialis)

The brachialis muscle has a deeper location than the biceps, however, it also belongs to the anterior shoulder group. The origin of the muscle is two-thirds of the lower surface of the humerus, limited by the deltoid tuberosity and the capsule of the elbow joint, as well as the lateral and medial intermuscular septum shoulder The brachialis muscle ends on the tuberosity of the ulna. The deeper part of the brachialis tendon is woven into the capsule of the elbow joint.

Main function: The brachialis muscle flexes the forearm at the elbow joint.

Shoulder extensors

Triceps brachii (m.triceps brachii)

The triceps brachii is represented by a large powerful muscle, which is divided into three heads and is located on back surface shoulder The long head begins on the scapula, the medial and lateral heads begin on the humerus.

Main functions: The triceps brachii muscle is an extensor muscle; it is involved in extension of the elbow joint of the forearm. In addition, through the long head, the triceps also extends the shoulder and brings it towards the body.

Elbow muscle (m.anconeus)

The anconeus muscle is triangular in shape and belongs to the extensor group. The origin of the m.anconeus lies on the posterior surface of the lateral epicondyle of the humerus. The olecranon muscle is attached to the posterior edge of the ulna.

Main functions: The elbow muscle extends the arm at the elbow.

Forearm muscles

The muscles of the forearm, like the muscles of the shoulder, are represented by extensors and flexors. Many muscle groups The forearms are multi-joint muscles, their action is aimed at movements in joints such as the wrist, elbow, finger joints and hand. Largest muscle forearm - brachioradialis, responsible for flexing the limb at the elbow joint.

The most complete answers to questions on the topic: “movement in the shoulder joint is ensured.”

"Muscles of the upper limb"

Musclesproducingmovementtop beltlimbs

Schematically, the movements of the upper limb girdle (scapula and clavicle) are divided into:

Movement forward and backward with abduction of the scapula from the spinal column and adduction to it.

Raising and lowering the scapula and clavicle.

Movement of the scapula around the sagittal axis with the lower angle to the medial and lateral sides.

Circular movement of the lateral end of the clavicle and at the same time the scapula.

These movements involve six functional muscle groups.

Movementforward

The forward movement of the upper limb girdle is produced by muscles that cross the vertical axis of the sternoclavicular joint and are located in front of it. These include:

pectoralis major, acting on the girdle of the upper limb through the humerus;

pectoralis minor;

anterior serratus.

Movementback

They are carried out by the muscles that cross the vertical axis of the sternoclavicular joint and lie behind it. This muscle group includes:

trapezius muscle;

rhomboid muscle, major and minor;

latissimus dorsi muscle.

Movementup

Raising the belt of the upper limb is performed by the following muscles:

1) the upper bundles of the trapezius muscle, which pulls up the lateral end of the clavicle and the acromion of the scapula;

levator scapulae muscle;

rhomboid muscles, during the decomposition of the resultant of which there is a certain component directed upward;

the sternocleidomastoid muscle, which, attaching one of its heads to the collarbone, pulls it, and, consequently, the scapula upward.

Movementdown

Lowering is facilitated by muscles that go from bottom to top, from the chest or spinal column to the bones of the upper limb girdle:

pectoralis minor muscle;

subclavius ​​muscle;

lower bundles of trapezius muscle;

inferior teeth of the serratus anterior muscle.

In addition, the muscles that go from the torso to the shoulder, namely the pectoralis major muscle and the latissimus dorsi muscle, help lowering, mainly through their lower parts.

Rotationshoulder blades(movementlowerangleinsideAndoutward)

Rotation of the scapula inward, with the lower angle to the spinal column, is produced by a pair of forces formed by:

pectoralis minor muscle

the lower part of the rhomboid major muscle.

Rotation of the scapula outward, with the lower angle from the spinal column to the lateral side, occurs as a result of the action of a pair of forces generated by the upper and lower parts of the trapezius muscle.

This movement is supported by:

serratus anterior muscle with its lower and middle teeth;

teres major muscle with a fixed free upper limb.

Circularmovement

The circular movement of the upper limb girdle occurs as a result of alternate contraction of all its muscles.

Musclesproducingmovement inshoulderjoint

In the shoulder joint, movements are possible around three mutually perpendicular axes:

abduction and adduction around the anteroposterior axis;

flexion and extension around the transverse axis;

pronation and supination around the vertical axis;

circular motion (circumduction).

These movements are provided by six functional muscle groups.

Leadshoulder

The shoulder abductor muscles cross the sagittal axis of rotation in the shoulder joint and are located lateral to it. The humerus is abducted by the following muscles:

deltoid and

supraspinatus.

Bringingshoulder

There are no special muscles that would cross the sagittal axis of the shoulder joint and are located medial to it, therefore, adduction of the shoulder according to the parallelogram of forces rule is carried out with the simultaneous contraction of muscles located in front (the pectoralis major muscle) and behind the shoulder joint (the latissimus and teres major). These muscles help:

infraspinatus;

small round;

subscapular;

long head of the triceps brachii muscle;

coracobrachial muscles.