Many people know about a muscle like biceps ( biceps), but few people understand the features of its structure and its true name. It is extremely difficult to swing your arms without this information, so it is advisable to familiarize yourself with all the anatomical details before drawing up a training plan. In this case, you can achieve the result in a shorter time frame.

The biceps brachii is attached to the bones of the scapula with a tendon. Muscle tissue got its name from the two heads that can be seen in this image:

The picture clearly shows what parts the biceps brachii consists of, namely:

• Short biceps head. This part of the biceps of the shoulder begins at the coracoid process on the outside of the scapula. From it, the muscle runs along the inner surface of the bone to the long head. The short half of the biceps does not have an oblong tendon, but it has more muscle tissue;
• Long biceps head. It is localized on the lateral surface of the upper limb and begins its path from the protrusion in the region of the scapula, which is located directly above the depression of the shoulder joint. This place is called the supra-articular tubercle. The long head has a rather pronounced tendon, but at the same time a short section of muscle tissue.

If you look from above at the structure of the biceps of the arm, you will notice that both heads intertwine with each other as they approach the elbow joint, creating a kind of abdomen. It is attached to the elbow with a bicep tendon. Together, both heads create a powerful flexor, i.e. a flexor.

Function

Having studied the structural features of the biceps brachii, you can understand what its main functions are. According to its anatomy, the biceps is the flexor of the limb in elbow joint and allows you to rotate (supinate) the brush. The long head of the muscle comes into action when the shoulder muscle tissue contracts, for example, when raising the arms up.

To fully stretch the long part of the bicep, the elbows will have to be pulled back. If you need to load the short head of the biceps, then they need to be moved slightly forward from the body. Such a nuance is useful for novice bodybuilders, since certain hand positions affect the pumping of problem muscle tissues. That is why any athlete should study the functions of the biceps before pumping their arms.

Stress points

The biceps of the shoulder during training is constantly loaded and excessive overexertion can create stress points. For example, this might happen during an uphill climb or after a barbell press. In bodybuilders, the main reason for the appearance of these points is the transfer heavy weight on the elbows or outstretched limbs. However, ordinary people are also not immune from them. After all, any activity accompanied by severe overloads can cause pain and weakness in certain parts of the arm, which are symptoms of tension points.

You can find out about their presence by pain in the area of ​​the biceps muscle. Sometimes the discomfort is localized to the front of the shoulder. At the same time, people pay attention to the restrictions that have arisen that did not exist before. For example, weakness when straightening the arm or the appearance of pain on palpation of the tendon on which the biceps is attached to the elbow.

To identify such points, put the limb on a flat surface in front of you. First, you need to bend it a little at the elbow joint. Then, with the help of feeling, you should look for stress points.

You need to start palpation from the ulnar fossa and gradually move along the tendon to the abdomen of the biceps.

Fingers should not be easy to poke, but smoothly lead, massaging the outer and inner sides of the muscle tissue. Seals can be felt along the way and stress points are often found near them. They are usually localized 1/3 of the way along the biceps muscle. When such places are found, they need to be massaged until the unpleasant sensations decrease.

Pain in the biceps muscle

The biceps muscle of the shoulder usually tolerates stress, but sometimes pain of a different nature arises in it. In such a situation, you need to know the reasons due to which it can manifest itself:

If you find suspicious symptoms in the biceps muscle, you should consult a therapist. For examination, he can send the patient to a physiotherapist, traumologist, rheumatologist, etc. After identifying the main cause of pain, an appropriate course of therapy is prescribed.

The biceps muscle is known to most people as the biceps. Knowing its features, you can quickly and effectively pump your arms and avoid injuries that are associated with excessive overload. However, this muscle is under constant tension, so care must be taken to avoid strange symptoms. If they are identified, you should immediately contact a specialist.

All muscles of the upper limb are usually divided into 2 groups: the muscles of the shoulder girdle and the free upper limb, which in turn consist of 3 topographic sections - the muscles of the shoulder, muscles of the forearm and hand. Many people mistakenly think that the muscles of the shoulder girdle also belong to the muscles of the shoulder, but according to the accepted anatomical classification, this is not the case. The shoulder is the portion of the free upper limb from the shoulder joint to the elbow joint.

All muscles of the shoulder anatomical region can be divided into posterior and anterior groups.

Anterior shoulder muscle group

These include:

• biceps brachii,
• coracohumeral muscle,
• brachial muscle.

Two-headed

It has two heads, from where it got its characteristic name. The long head originates from the tendon from the supra-articular tubercle of the scapula. The tendon passes through the articular cavity of the shoulder joint, lies in the intertubercular groove humerus and passes into muscle tissue. In the intertubular groove, the tendon is surrounded by a synovial membrane, which connects to the cavity of the shoulder joint.

The short head originates from the apex of the coracoid process of the scapula. Both heads merge together and pass into fusiform muscle tissue. Slightly above the cubital fossa, the muscle narrows and passes again into the tendon, which is attached to the tuberosity of the radius of the forearm.

Functions:

• flexion of the upper limb in the shoulder and elbow joints;
• supination of the forearm.

Coracohumeral

Begins muscle fiber from the coracoid process of the scapula, attached to the humerus approximately in the middle with inside.

Functions:

• flexion of the shoulder at the humeral articulation;
• bringing the shoulder to the body;
• takes part in turning the shoulder outward;
• pulls the scapula down and anteriorly.

Shoulder

This is enough broad muscle, which lies directly under the biceps. It starts from the front surface of the upper part of the humerus and from the intermuscular septa of the shoulder. Attaches to the tuberosity of the ulna. Function - flexion of the forearm at the elbow joint.

Posterior muscle group

This group includes:

• triceps muscle of the shoulder,
• ulnar,
• muscle of the elbow joint.

Three-headed

This anatomical formation has three heads, hence the name. The long head originates from the subarticular tubercle of the humerus and below the middle of the humerus passes into the tendon common to the three heads.

The lateral head starts from the posterior surface of the humerus and the lateral intermuscular septum.

The median head starts from the posterior surface of the humerus and both intermuscular septa of the shoulder. It is attached with a powerful tendon to the olecranon of the ulna.

Functions:

• extension of the forearm at the elbow joint;
• adduction and extension of the shoulder due to the long head.

Ulnar

It is, as it were, a continuation of the median head of the triceps brachii muscle. It originates from the lateral epicondyle of the humerus, and is attached to the posterior surface of the olecranon of the ulna and to its body (proximal part).

Function - extension of the forearm at the elbow joint.

Elbow muscle

This is a fickle anatomical formation. Some experts consider it as part of the fibers of the median head of the triceps muscle, which are attached to the capsule of the elbow joint.

Function - tightens the capsule of the elbow joint, which prevents it from being pinched.

Muscles of the shoulder girdle

It is worth mentioning the muscles of the upper limb girdle, which are often referred to as the muscle formations of the shoulder:

• deltoid shoulder,
• supra- and infraspinatus muscle,
• small and large round,
• subscapularis.

Both muscle groups of the shoulder are separated from each other by two connective tissue intermuscular septa, which extend from the common brachial fascia (enveloping the entire muscular frame of the shoulder) to the lateral and median edges of the humerus.

Pain in the muscles of the shoulder

Pain in the shoulder and shoulder girdle area is a common complaint of people of different age groups... Such a symptom may be associated with the pathology of the skeleton, joints, ligaments, but most often the reason is hidden in damage to muscle tissue.

Causes

Consider the most common causes of shoulder pain:

• overstrain and sprain of ligaments, tendons, muscles;
• diseases or traumatic injuries of the shoulder joint;
• inflammation of the ligaments and tendons of the muscles (tendonitis);
• rupture of tendons and muscles;
• joint capsulitis (inflammation of the joint capsule);
• inflammation of the periarticular bags - bursitis;
• frozen shoulder syndrome;
• humeral periarthrosis;
• myofascial pain syndrome;
• vertebral causes of pain syndrome (associated with damage to the cervical and thoracic spine);
• impingement syndrome;
• polymyalgia rheumatica;
• myositis of an infectious (specific and nonspecific) and non-infectious nature (with autoimmune, allergic diseases, ossifying myositis).

Pain in the shoulder area can be associated with damage to the bones, joints, ligaments, and damage to muscle tissue

Differential diagnosis

The following criteria will help distinguish shoulder pain caused by muscle damage from joint diseases.

Sign	Joint diseases	Muscle lesions
The nature of the pain syndrome	The pain is constant, does not disappear at rest, slightly increases with movement	Pain occurs or significantly increases with a certain type of physical activity (depending on the damaged muscle)
Localization of pain	Unlimited, diffuse, spilled	Has a clear localization and certain boundaries, which depends on the localization of the damaged muscle fiber
Dependence on passive and active movements	All types of movement are limited due to the development of pain syndrome	Due to pain, the amplitude of active movements decreases, but all passive ones remain in full
Additional diagnostic signs	Change in the shape, contours and size of the joint, its swelling, hyperemia	The joint area is not changed, but there may be swelling in the soft tissue area, slight diffuse redness and an increase in local temperature with inflammatory causes of pain

What to do?

If you suffer from shoulder pain associated with muscle damage, the first thing to do in order to get rid of such an unpleasant symptom is to identify the provoking factor and eliminate it.

If after this the pain still returns, you need to visit a doctor, perhaps the cause of the pain syndrome is completely different. The following recommendations will help you quickly get rid of pain:

• in case of acute pain, it is necessary to immobilize the sore arm and provide it with complete rest;
• you can take 1-2 tablets of an over-the-counter pain relieving non-steroidal anti-inflammatory drug on your own or apply it to the affected area in the form of an ointment or gel;
• massage can be used only after the elimination of acute pain syndrome, as well as physiotherapy;
• after the pain subsides, it is important to exercise regularly physiotherapy exercises to develop and strengthen the muscles of the shoulder;
• if a person on duty is forced to perform daily monotonous movements with his hands, it is important to take care of protecting the muscles and preventing their damage (wearing special bandages, protective and supporting orthoses, doing gymnastics for relaxation and strengthening, taking regular therapeutic and prophylactic massage courses, etc.).

Typically, treatment muscle pain caused by overexertion or minor injury, lasts no more than 3-5 days and requires only rest, minimum load on hands, correction of the rest and work regimen, massage, sometimes taking non-steroidal anti-inflammatory drugs. If the pain persists or it initially has high intensity, accompanied by other warning signs, in mandatory you need to visit a doctor for examination and correction of treatment.

What is the biceps brachii? Where is it located, and what are its features anatomical structure? We will try to answer these and other questions regarding what is the biceps brachii muscle in the course of this article.

What is it about?

From the very beginning, we will introduce the correct idea of ​​this part of the body, since the term "shoulder" for a person far from anatomy is represented by a part of the body that is located in the interval between the neck, back and arm of the human body. However, this is not the case. The shoulder section starts from the elbow and continues to the shoulder bend, which is just the same near the neck. What is generally considered to be a shoulder in the everyday sense actually carries the term “ shoulder girdle". This part of the body serves to connect the upper limb to the trunk. The movement of the hand also depends on it.

Structure

Now let's move on to the biceps muscle itself, also called "biceps". Everyone knows this part of the body. And the more famous muscle, perhaps only the heart muscle. The biceps consists of two parts:

Short head.

The long part of the biceps muscle originates from the scapula itself (supra-articular tubercle). From it, it stretches along the back of the shoulder and reaches the elbow, where it is intertwined with a short head. The attachment of the short head is located on the coracoid process. This process is located on the outside of the scapula. Its length reaches the elbow, passing through the entire interior humerus. Closer to the elbow, the short head intertwines with the long head, forming a kind of lump. It is called biceps.

The biceps brachii is attached to the bones. The biceps is a powerful flexor due to its connection to the elbow joint. Due to the fact that the biceps is attached to the radius, it is also the instep support of the hand. Thanks to the biceps, the hand bends, turns, etc. If the elbow is at a right angle, then the hand turns towards the ceiling. If the elbow is in a straight position, then the palm turns forward.

Biceps brachii. Functions

As we already know, the biceps muscle is responsible for bending the arms at the elbows, and also twists the hands in different directions. The biceps can also be used by raising the arms in front of you. This is due to the attachment of its long head to the muscles of the scapula. Based on this, in order to fully straighten the long head of the biceps muscle, it is necessary to spread the outstretched arms to the sides, and then, without bending, direct them back.

Muscle tendon

The biceps tendon is easy to spot when the arm is bent. The short and long heads are easy to feel under the skin. The same applies to the tendon part of the muscle.

Correct action on the long head of the biceps muscle

In order for the effect of the exercise to be most effective in the long head, the arms must be constantly extended at the elbows. In other words, they should be in a backward direction relative to the body. Stretched out long head has more tension, which contributes to the rapid impact of the load on the muscle. Otherwise (without full extension of the arms), the tension goes into the short head. An example would be Scott's bench press.

Why might a gap occur?

As a rule, this phenomenon is characteristic of those who are already over 40. Most often this happens when a person is carrying some kind of load in front of him. For example, when unloading a machine, it is very easy to tear a muscle. Especially if the weight of the load exceeds 70 kg. A rupture can also occur when interacting with lighter loads in the event that the muscle tissue is subject to any changes. This can be both adolescence and old age. It is especially common for older people to get tears due to the loss of strength of the biceps muscle. And it is inevitable. For women, this phenomenon is practically not typical due to the rare loads on the hands.

In order to prevent rupture, you need to warm up the muscles of your arms whenever it comes to stress. Catching up in gym, it is necessary to knead the muscles in the part to which it is directed before each exercise. It seems funny if a man, unloading the car, will warm up his arms in front of each box. However, these are normal safety measures for muscles to avoid rupture.

You should not lift weights abruptly, as this is a high probability of a rupture. It is necessary to have a certain attitude to lift each weight or perform a movement on the simulator. Abrupt, spontaneous execution (especially in the presence of long respites) will only bring harm, not benefit.

Also, training of a fickle nature can be a frequent reason. If a person goes in for sports at a time when he pleases, and does not adhere to a certain regime, then sooner or later this ailment may overtake him.

Myths about strengthening the biceps tendons

As such, actions that strengthen tendons in adulthood do not exist. At least for today. Although nowadays there is a popular rumor about the effective effect of prolotherapy. Only in fact, this procedure is in the research stage. And if their results turn out to be positive, then the provision of the proper effect on the biceps muscle will be almost unrealistic. This procedure is most likely ideal for the proximal tendons.

The addition of dietary supplements to food also does not have the desired effect, no matter how manufacturers claim otherwise. You can often hear about the miraculous effect on the tendons of eating jellied meat. But this is also a myth. As well as chicken cartilage and meat broths, which do not in any way affect the strength of the biceps tendons.

They are divided into two groups: front (flexors), back (extensors). These groups are separated from each other by plates of the own fascia of the shoulder: from the medial side - the medial intermuscular septum of the shoulder, with the lateral-lateral intermuscular septum of the shoulder.

Anterior shoulder muscle group:

1. Coracobrachial muscle (m. Coracobrachialis)

From the apex of the coracoid process to the humerus below the crest of the lesser tubercle. Part of the bundles is woven into the medial intermuscular septum of the shoulder.

Functions:

Flexes the shoulder at the shoulder joint and brings it to the torso;

If the shoulder is pronated, then the muscle participates in its supination;

If the shoulder is fixed, the muscle pulls the scapula forward and downward.

2.Biceps brachii (m. Biceps brachii)

Has two heads:

Short head (caputbreve) begins with the coracohumeral muscle.

Long head (caputlongum) starts from the supra-articular tubercle of the scapula with a tendon that penetrates the capsule of the shoulder joint and lies in the intertubercular groove, where it is fixed by the transverse ligament of the shoulder (lig.transversum humeri), stretching between the large and small tubercles of the humerus. In the joint cavity and in the groove, the tendon is surrounded by a synovial sheath (vagina tendinis intertubercularis). At the level of the middle of the shoulder, both heads are connected to a common abdomen, which is attached to the tuberosity of the radius. From the tendon to the medial side departs aponeurosis of the biceps brachii (aponeurosis musculi bicipitis brachii) that merges with the fascia of the forearm.

Functions:

Flexes the shoulder at the shoulder joint;

Flexes the forearm at the elbow joint;

Supine forearm.

3.Shoulder muscle (m. Brachialis)

It begins between the deltoid tuberosity and the articular capsule of the elbow joint, the medial and lateral muscular septa of the shoulder.

Attaches to the tuberosity of the ulna

Function: flexes the forearm at the elbow joint.

Posterior shoulder muscle group

1. Triceps brachii (m. Triceps brachii)

Has three heads:

Lateral head (caputlaterale) begins on the outer surface of the humerus, the bundles pass down and medially, covering the groove of the radial nerve.

Medial head (caputmediale) from the back of the shoulder

Long head (caputlongum) from the sub-articular tubercle of the scapula, passes down between the small and large round muscles to the middle of the posterior surface of the shoulder, where its bundles are connected to the medial and lateral heads. It is attached to the olecranon of the ulna; some of the bundles are woven into the capsule of the elbow joint and into the fascia of the forearm.

Functions:

Extends the forearm at the elbow joint;

The long head is involved in the extension and adduction of the shoulder to the body.

2. Elbow muscle (m. Anconeus)

It begins on the posterior surface of the lateral epicondyle of the shoulder.

Attaches to the lateral surface of the olecranon, the posterior surface of the ulna, and the fascia of the forearm.

Function: participates in the extension of the forearm.

Fascia of the upper limb

Superficial fascia of the upper limb represented by a layer of subcutaneous adipose tissue, the amount of which varies individually. The thickness of the skinfold on the back of the shoulder is one of the anthropometric indicators of obesity.

Deep (intrinsic) fascia differs in its structure in different areas of the upper limb. The deep fascia covering the muscles of the shoulder girdle is isolated five parts.

1. Deltoid fascia (fascia deltoidea) surrounds the muscle of the same name, forms numerous partitions between its bundles; from the front it connects to the fascia pectoralis, from the back - to the fascia infraspinata, at the top it is attached to the clavicle, acromion and spine of the scapula, from below it continues into the fascia of the shoulder.

2. Supraspinatus fascia (fascia supraspinata) It is a thin fibrous plate that attaches along the edges of the supraspinatus fossa of the scapula, forming a fibrous bone sheath for the supraspinatus muscle, in the medial section it is thicker.

3. Subspinal fascia (fascia infraspinata), is a well-defined strong aponeurotic plate, attaches to the scapula along the edges of the infraspinatus fossa, forms a bone-fibrous sheath for the infraspinatus muscle.

4. Subscapular fascia (fascia subscapularis) is a thin fibrous plate that attaches along the edges of the scapular fossa, forming a fibrous bone sheath for the subscapularis muscle.

5. Axillary fascia (fascia axillaris) is formed as follows: the pectoral fascia in the interval between the edges of the pectoralis major muscle and the broadest muscle of the back thickens, forming the bottom of the axillary cavity, here it is called the axillary fascia, continues into the fascia of the shoulder.

Fascia of the shoulder (fascia brachii) surrounds the muscles of the shoulder; from its inner surface, two intermuscular septa depart deeply - medial and lateral (septum intermusculare brachii mediale etlaterale) that attach to the humerus and separate the anterior and posterior muscle groups. The medial intermuscular septum separates the coracohumeral muscle from the medial head of the triceps brachii. The lateral intermuscular septum separates the brachialis and brachioradialis muscles from the lateral head of the triceps muscle.

As a result, two fascial beds are formed - front (compartimentumbrachiianterius) and rear (compartimentumbrachiiposterius).

Covering the anterior shoulder muscle group, the fascia divides into two plates, forming a separate fibrous sheath for the coracohumeral and biceps muscles and a fibrous sheath for the brachialis muscle. The triceps muscle of the shoulder lies in a separate osteo-fibrous sheath. In the lower third of the shoulder, the medial saphenous vein of the arm (v. Basilica) lies in the subcutaneous tissue, on the border with the middle third, it pierces its own fascia and throughout the middle third of the shoulder lies in the splitting of the fascia (Pirogov's canal), in the upper third of the shoulder the vein goes under its own fascia and flows into one of the brachial veins.

Fascia of the forearm (fascia antebrachii) is a continuation of the deep fascia of the shoulder, it forms a dense sheath for all the muscles of the forearm together and for each muscle separately. The fascia of the forearm attaches to the olecranon and to the posterior edge of the ulna.

The movement of the joints of the limbs is carried out due to the work of the muscles located on them. They consist of special fibers arranged in bundles. V human body there are about 400 muscles that, under the influence of impulses from the central nervous system able to change the position of the body.

Types of muscle tissue

Movement is impossible without the participation of muscles. total weight of such tissues in the body of an adult is in the region of 30-40%. In newborn babies, it is about 20%, in older people it decreases to 25-30%. But if a person, even at an honorable age, remains active, then muscle mass does not decrease, it remains at the same level.

Experts highlight different groups muscles depending on their location, functions, direction of fibers. The following types of muscles are distinguished by location:

Superficial (located under the skin);

Deep;

Lateral;

Medial;

Outdoor;

Internal.

According to the shape, experts distinguish fusiform, square, triangular, circular, ribbon-like muscles. According to the number of heads, they can be two-headed, three-headed and four-headed. Depending on the direction of the beams, they are single-pinnate, two-pinnate or multi-pinnate.

Muscles are also distinguished by function. Some provide extension of the limbs, others flexion. Rotators-lifters, compressors (sphincter), abductor and adductor muscles are distinguished separately.

For example, the humeral biceps is fusiform. It is attached to the bone, which is the lever, and allows the arm to bend at the elbow.

Shoulder biceps

The biceps belongs to the anterior group of muscles. It is located on the front of the humerus. This long, fusiform muscle has two heads. One of them is long, the other is short. They walk side by side, heading from top to bottom. At the level of the middle part of the shoulder, they are connected to form a fusiform abdomen.

The long head of the biceps originates in the form of a rounded tendon in the supra-articular tubercle of the scapula. It goes through shoulder joint top down. Inside it, the tendon is covered with a synovial membrane. And in the region of the exit to the shoulder, it passes in the intertubercular groove. There it is enveloped in the synovial intertubercular sheath.

The short head originates in the same place as the coracohumeral muscle, at the apex of the cranioid process. Together they join in the middle of the humerus. This forms the biceps, which is supplied with blood from the axillary, lower and upper ulnar collateral, brachial and recurrent radial arteries.

At the end there is the biceps tendon of the shoulder, which goes to the tuberous part of the radius. The transition from muscle to tendon tissue takes place directly above or near the elbow joint. At the site of attachment of the tendon, there is a two-headed bursa. A wide, thin dense aponeurosis extends from its antero-medial side. It is known as Pirogov's fascia. In front, it covers the cubital fossa. This aponeurosis is woven into the fascia of the forearm.

Triceps muscle

Along the back of the humerus is a muscle that extends the arm at the elbow. It has a fusiform shape. Two-headed and differ not only in location, but also in structure. Triceps has three heads: long, medial and lateral. The first of them begins on the sub-articular tubercle of the scapula in the form of a rounded thick tendon. It often connects to the latissimus dorsi tendon. The muscular abdomen of this head passes between the circular muscles (small and large) and stretches to the middle of the humerus.

The lateral head is partially covered by the deltoid muscle of the triceps. It originates from the back of the humerus. The bundles from it go down medially so that they overlap the groove radial nerve.

The medial head is the shortest of the three. It begins with collected bundles of muscle at the back of the humerus. A significant part of it is covered by lateral head... Between them and the groove of the radial nerve is the brachio-muscular canal.

In the middle part of the back surface of the shoulder, all three heads are connected to each other and form the abdomen. It ends with a thick tendon that attaches to a special process of the ulna.

Flexion and extension in the elbow joint of the forearm is provided just by the biceps and triceps brachii. Also involved in this process and the shoulder muscle, called the brachialis.

Leg muscles

On the side of the posterior surface of the femur, the posterior muscle group... It includes the biceps, semitendinosus and semimembranous muscles. They all begin in the area of ​​the ischial tuberosity. Their beginning is covered with great

Moreover, if the semitendinosus and semimembranous muscles are located medially, then the biceps occupy a lateral position. The femoral bicep is extended along the entire length of the femur, it has a fusiform shape. It is adjacent to the wall of the popliteal fossa and forms the femoral biceps muscle. It can perform its functions due to its special structure and attachment to another bone.

It starts with two heads - long and short. At the beginning of the first of them there is a short thick tendon. It is located on the surface of the sacro-tuberous ligament and ischial tuberosity. The muscle does not go straight down, but obliquely in the lateral direction. The lower end is attached to the lower leg.

The short head of the biceps femoris starts from its lower edge ends at the tibia (lower leg).

Both heads are connected at the border between the lower and middle part of the femur. They go into one common tendon. It is this that passes from the back of the knee joint. The specified tendon is attached to (its head) and the outer part of the lateral condyle, which belongs to the tibia. In part, its fibers are woven into the fascia of the lower leg.

Bicep functions

Depending on what kind of work the muscles can do, they are divided into flexors and extensors. These are oppositely acting muscle groups that provide movement of the limbs. The main flexor muscle of the upper is the biceps brachii.

It performs the following functions:

Flexes the arm at the elbow;

Provides the ability to rotate the brush outward;

Strains the arm in the elbow.

The main flexor of the upper leg is the biceps femoris.

Leg biceps functions:

Extension and adduction of the hip;

Straightening the torso after bending;

Flexion in the knee joint of the lower leg;

Turning to the outside of the lower leg bent at the knee joint;

Maintaining balance.

It is worth noting that problems with the biceps, such as lack of strength or flexibility, lead to back pain, problems with knee joints, and poor posture.

Extension upper limbs provided by the activity of the triceps, located along the humerus. Two-headed and triceps can be shortened together or alternately. The movement of the leg in the knee joint is facilitated by the coordinated work of the biceps and quadriceps muscles.

Leg extensor

The most big muscle in the human body is the quadriceps. It is located on the front of the thigh and provides the ability to extend lower limb in the knee area. She is also responsible for hip flexion - bringing this part of the leg to the stomach.

The quadriceps consists of four beams. Each of them is considered a separate muscle that has its own name. Separately, experts distinguish the rectus, broad lateral, medial and intermediate muscles.

They are all attached to the patella. But each of them has its own functions. For example, the straight line is responsible for hip flexion and extension knee joints... But the intermediate, medial and lateral are necessary for the extension of the lower leg.

Providing movement

Without the coordinated action of the muscles, it would be impossible to bend or unbend the limbs. The voluntary movement of the biceps muscle is regulated spinal cord... This becomes possible due to the alternation of the processes of inhibition and excitation that take place in the spinal cord. The muscles responsible for flexion and extension of the limbs can be relaxed at the same time. This happens, for example, while the arm hangs relaxed along the body.

Their reduction occurs due to the activity of the neurons in the spinal cord, which are responsible for movement. The relaxation process is associated with the inhibition of these cells of the nervous system. If a person holds a dumbbell in a straight outstretched hand, then the biceps and triceps muscles will work at the same time.

When nerve impulses arrive, the muscle receives a specific command, depending on this, the process of relaxation or muscle tension begins. When contracted, it acts on the bone to which it is attached, like a lever.

How muscles function

Contraction of any muscle group is energy-intensive work. Its source can be products released during the decay and oxidation of various organic substances. In the drags of the muscles, they undergo various chemical reactions with the help of oxygen. The result of this interaction is the release of energy. This is accompanied by the formation of fission products - carbon dioxide and water.

When the muscles are loaded too much, the natural process of fatigue begins. This is accompanied by a decrease in their performance. After rest, everything is restored.

It was noted that when performing rhythmic exercise fatigue sets in a little later. Indeed, in the intervals between contractions, the muscles partially have time to rest and recover. But the intensity of the load also affects the performance. The higher it is, the faster fatigue will come.

The work of the central nervous system

Making this or that movement, a person does not think. He does everything automatically. But at the same time, each motor act for the nervous system is a complex process, for the implementation of which it is necessary to involve its various levels. All active movements are controlled by the brain. They are called voluntary or conscious.

Before muscle contraction begins, the cerebral cortex receives information through special channels about the state of the joint-muscle fibers. She assesses how ready they are for the load. Therefore, it cannot be said that the voluntary movements of the biceps muscle are regulated exclusively by the spinal cord. After all, the bark controls the strength, sequence and duration of each of the contractions.

The motor centers are located in the frontal part of the brain of the cerebral cortex. It is in the anterior regions that all signals are integrated. After that, the formation of a model of the future movement takes place.

In order for the voluntary muscle contraction to occur, the impulses formed in the cortical part of the brain must reach the corresponding muscles. They follow a special path that experts call cortical-muscular. Voluntary movements of the biceps muscle are regulated by central and peripheral neurons. The first of these are the bodies of pyramidal cells with axons. The second are the cells of the spinal cord.

Neurons connect the part of the cerebral cortex responsible for movement, special parts of the spinal cord and brain stem. This whole complex is called the pyramidal system.

Possible problems

It happens when some part of the cortical-muscular pathway is affected. In this case, the muscles do not receive the signal from the cerebral cortex. Their voluntary movements become impossible.

For example, with partial damage, the biceps muscle cannot perform its functions in full. Depending on the location of the lesion, problems can arise in different parts of the body. Partial damage usually results in paresis.

With such injuries, the voluntary movements of the biceps muscle are also regulated by the brain and spinal cord. But due to a violation of connections, a violation, limitation of the intensity and strength of contractions is possible. Problems can be central or peripheral, depending on which neurons are affected.

The examination of such patients should be thorough. During it, it is important to determine not only how the motor function was preserved, but also check for the presence of muscle atrophy. They also look at whether there are deformations chest, spine, are there any small twitching of the muscles.

But, it is worth noting that it is not always only because of problems with the cortical-muscular path that movements become impossible. For example, with pathologies of the articular apparatus, impaired proprioceptive sensitivity, the biceps brachii muscle may stop working. It will not perform its functions in full even if cicatricial changes appear in the muscles. Therefore, it is important to determine the reason due to which the contractions of the muscles became impossible. For these purposes, they investigate how the patient can perform active and passive movements, evaluate his reflexes.