The chest muscles are one of the largest muscle groups in humans, which are located on the outer surface of the thoracic region. Their structure is fan-shaped and consists of 3 main muscle bundles.
The chest muscles can be divided into two structures.
The first group includes muscle fibers related directly to the shoulder girdle:
- pectoralis minor muscle;
- large chest muscle;
- toothed;
- subclavian muscle.
The second belongs to the pectoral muscles themselves:
- external intercostal muscles;
- internal intercostal muscles.
They are located in the intercostal spaces and are responsible for contracting the human diaphragm.
1. Large chest muscle has a powerful muscular structure and therefore occupies 90% of the chest. The main feature is their pairing and flatness. It is this structure that predisposes to the development of maximum hypertrophy of the muscle group.
Main functional features
The pectoralis major muscle is responsible for lowering the arm from the top position directly to the body. At the same time, she makes a simultaneous rotation of the arm towards the inside of the body. The large lever allows you to make the above movement powerful, fast and strong, which is exactly what is needed for heavy chest training.
2. Pectoralis minor muscle its shape resembles a flat triangle and is located under the main muscle. It begins in the area of the ribs and is attached directly to the shoulder blade.
Main functional feature is aimed at moving the scapula and pulling it back and forth.
3. Anterior serratus located lateral to the front of the pectoral muscle, which starts from the ribs and attaches in the area of the scapula.
Subclavius muscle located directly in the collarbone area.
Main functional activity the anterior muscle is aimed at turning and moving the scapula forward. The second muscle has one function - it moves the collarbone down.
4. Intercostal muscles There are two types: internal and external. They are attached to different parts of the ribs: this is necessary to ensure the normal process of exhalation and inhalation.
Subcostal muscles are attached to the inside of the lower ribs. The main difference from the intercostal muscles is the uneven and less frequent attachment of muscle bundles.
Diaphragm- This is a muscle structure responsible for human breathing. It is movable, consisting of a septum that is located between the cavities of the chest and abdomen.
Functional features:
When the diaphragm contracts, the chest plane moves away and increases, and the abdominal plane decreases accordingly. The above action is accompanied by a person’s inhalation.
Contraction of the abdomen and diaphragm increases intra-abdominal pressure. This integral physiological characteristic is very important when working with extreme weights.
What should be noted from all of the above?
1. Firstly, the chest muscles are unique in their physiology and genetic predisposition to growth. The muscle fibers of the chest are located in different directions. That is why it is necessary to train the chest from different angles.
2. Secondly, the chest muscles are a large muscle group, so they are able to work in strength mode and tolerate high-intensity training.
The chest muscles are a fairly large formation on the surface of the human body. They perform many important functions, which will be discussed in this article. Thus, they allow us to protect our internal organs and chest from various injuries - and this is not all of their positive properties.
Anatomy of the chest muscles:
Superficial chest muscles:
- Pectoralis major muscle
Pectoralis major muscle:
Acts as one of the strongest as well as largest muscles in the human body, and covers a large area of the chest at the front. Their shape resembles a fan, they are flat and paired. Its main functions include lowering and bringing the raised arm to the body - while it is possible to rotate it inward, it also takes part in the breathing process, since it has the property of raising the ribs with well-fixed upper limbs.
They originate from the crests of the humerus bones, or, more precisely, from their large tubercles. Saturation with blood occurs through the arteries, as well as the acromion process, which is located on the chest. The pectoralis major muscle quickly begins to increase in size with systematic training, which is a definite plus for athletes, as well as for those who simply want to give their body a beautiful look.
This is a flat muscle that is located under the pectoralis major and has a triangular shape. Its teeth start from the 2nd and end on the 5th rib; the muscle itself is attached to the coracoid process of the scapula.
The main function of this muscle is to move the scapula inward, forward and downward. If the shoulder blade is in a fixed position, then the ribs are lifted.
In terms of its structure, it is a flat and rather wide muscle, and it is located on the side of the surface of the pectoral muscles. It originates from the upper ribs and is attached with teeth to the medial edge of the scapula.
The main function of the serratus anterior muscle is to pull the scapula forward and outward, while rotating. Also, it helps to rotate the shoulder blade of the raised arm until it reaches a vertical position.
The subclavian muscle is located between the collarbone and the upper rib, which is why it got its name. This muscle is small but quite important in various rotational movements.
The main function of the subclavius muscle is to move the collarbone downward and inward, and it also helps strengthen the sternoclavicular joint. If the shoulder girdle is fixed, it is capable of raising the 1st rib.
Deep chest muscles:
External and internal intercostal muscles:
The external intercostal muscles are located on the surface in the spaces between the ribs, from the spine to the cartilaginous costal tissue. They originate from the lower edge of the ribs, and are attached to the upper edge of the underlying rib. Their main function is to raise the ribs.
The internal intercostal muscles are located under the external ones and have a different fiber structure, to be more precise, the opposite one - thus they intersect with the fibers of the external muscles at an angle. They originate at the edge of the underlying rib, and then extend upward and forward, attaching to the overlying rib, reaching the sternum and are located between the cartilages of the ribs. The main function of the internal intercostal muscles is to lower the ribs. These 2 types of muscles take part in the process of Inhalation - Exhalation.
These muscles are located - bundles on the inner surface of our lower ribs. They differ from intercostal ones in that they span over one or even two ribs at once.
The main function of the hypochondrium muscles is the process of lowering the ribs. Thus, they take part at the moment when we exhale.
They originate in the form of a tendon from the inner surface of the xiphoid process and the edge of the lower part of the sternum. They are attached to the cartilage of the inner surfaces of the ribs with 4 - 6 teeth.
The main function of the transverse chest muscles is to lower the ribs, to be more precise, ribs 2 - 5, they also take part in the act of Exhalation.
Exercises that will help you develop the above muscles:
- Exercises for the pectoral muscles
- Basic exercises in bodybuilding
Anatomy of the pectoral muscles video:
Often, beginners and even experienced athletes do not pay enough attention to studying the anatomy of the muscles being trained. And this is a fundamentally wrong approach to training. Knowledge of the structure of your body and the location of muscles makes it possible to increase the effectiveness of the training process. Today we will discuss the anatomy of the pectoral muscles.
Anatomical structure
The chest muscle group consists of three main muscles.
Pectoralis major muscle, or m. pectoralis major is the most massive, occupies a large area of the sternum, and is shaped like a fan. It originates from the clavicle (medial region), the anterior part of the sternum and the rectus abdominis muscle. Attached above to the humerus. The lateral side is adjacent to the edge of the deltas. Its main task is to turn, lift and bring the limb to the body. While climbing, it helps in pulling up the body. According to the anatomy of the structure, this muscle is the most susceptible to growth.
The pectoralis major, in turn, consists of three heads:
- The clavicle is located under the collarbone and is attached to it on one side.
- The sternocostal is located over the entire area of the pectoralis, originates in the anterior region, and is attached to the humerus.
- The abdominal muscle is attached to the rectus abdominis muscle on one side and to the shoulder bone on the other.
Small(m. pectoralis minor) is located under the large muscle and is shaped like a triangle. It starts between 2-5 ribs, goes to the scapula and attaches to it at the site of the coracoid process. Its task is to ensure the movement of the scapula (forward, downward, inward). When fixing the scapula, the small one ensures that the rib rises when inhaling.
Anterior serratus, or m. serratus anterior is a wide muscle located on the side of the sternum. On one side it is attached to the upper ribs, on the other - on the medial edge of the scapula. The serratus muscle provides rotation of the scapula, as well as its rotation when raising the arm vertically. It plays an important role not only in breast formation, but also in improving the athlete’s physical performance.
The anatomy of the pectoral muscles also includes the following::
- Subcostal– are located in the area of the lower ribs, on their inner surface.
- Intercostal– internal and external – involved in breathing.
- Diaphragm– the main muscle in the “inhalation-exhalation” process. According to anatomy, it is a muscle-tendon septum located between the abdominal and thoracic regions. By contracting together with the press, the diaphragm participates in increasing intra-abdominal pressure. The latter is especially important when working with heavy weights.
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Osseous-ligamentous apparatus
We have dealt with the anatomy of the pectoral muscles, but I would also like to dwell on the osseous-ligamentous apparatus. The muscles of the chest include the following:
- Scapula plays an important role in basic chest exercises. For example, during a bench press, when the shoulder joints are abducted, the scapula provides stable support for the torso.
- Humerus also participates in work on the major and minor pectoralis. It consists of 2 joints, forming the shoulder girdle. The latter is easily injured in bench presses if there is not enough support.
- Elbow joint. Its position is also important in movements for the pectoralis major and minor muscles.
Chest workout
The peculiarity of the work of the pectoralis major and minor muscles is that they respond well to load. Therefore, to work them out, it is recommended to use basic techniques and heavy working weights. The pectorals cannot tolerate overload - countless sets and repetitions - otherwise their growth will be inhibited. The special anatomy of muscles requires loading from different angles. We should not forget about the correct execution technique, because a qualitative increase in target volumes depends on it.
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It is better to train the large and small chest muscles in a split, once a week. Do not include training on the pecs and triceps at the same time, as their work is closely related.
Push-ups are the best exercise for working the pectoral muscles. To better pump up target muscles, bodybuilders use push-up supports. This is a convenient mobile mini-simulator that allows you to work out the pectoral muscles, deltoids, upper back muscles, arms, and abs. Accordingly, the range of motion, the effectiveness of the load and stretching of the pectoral muscles increase. You can buy push-up supports
The pectoralis minor muscle is the “smaller sister” of the more massive and well-known pectoralis major muscle. However, even a muscle this small can cause serious problems. It is located under the pectoralis major muscle, originates from the 3rd, 4th and 5th ribs, passes laterally upward and is attached to the coracoid process of the scapula.
The functions of the pectoralis minor muscle are: stabilization of the scapula, as well as its lowering, retraction and downward rotation. When the scapula is in a fixed position, this muscle also takes part in lifting the chest. Having explained the functions pectoralis minor, the site will tell you what problems may be associated with it.
Condition of the pectoralis minor muscle and postural disorders
The pectoralis minor muscle is a fairly significant factor in the formation of correct (or incorrect) posture. One of the functions pectoralis minor is retraction of the scapula - its movement forward, away from the spine, and around the chest, which leads to slouching in the shoulders.
Unfortunately, the lives of most of us are dominated by a sedentary lifestyle - we spend the lion's share of time at computers, driving, leaning over the desk in unnatural positions, when our shoulders are rounded and tilted forward, our backs are hunched. Over time, this position inevitably leads to overstrain of the pectoralis minor muscle (the appearance of muscle knots, or clamps).
Postural disorders- although large, it is not the only problem caused by overstrain of the pectoralis minor muscle. Therefore, the site will consider below:
- what symptoms and problems appear with overexertion pectoralis minor;
- what is pectoralis minor syndrome?
- how to get rid of pain caused by overexertion of the pectoralis minor muscle.
Overstrain of the pectoralis minor muscle: the starting point of serious disorders
An overused pectoralis minor muscle significantly affects the function of the shoulder joint and increases the risk of injury.
Perhaps the most common problem associated with pectoralis minor, is subacromial impingement syndrome.
In this case, the lack of space in the area between the humerus and the acromion leads to pinching of the tendons of the supraspinatus muscle and subacromial bursa, especially when raising the arm above the shoulder, as well as during rotational movements.
Pinched tendons, nerves and blood vessels in the shoulder and chest area are the consequences of overstraining the pectoralis minor muscle.
This lack of space may be directly related to a tight pectoralis minor muscle due to anterior tilt of the scapula and decreased subacromial arch.
In this case, patients complain of:
- dull pain in the shoulder;
- increased pain when raising the arm up;
- problems sleeping as a result of pain, especially when lying on the affected side;
- a characteristic crunching or clicking sound when lowering your hand;
- limitation of joint mobility;
- weakness in the hand.
In addition to increasing the risk of entrapment, a tight pectoralis minor muscle along with the serratus anterior muscle moves the glenoid fossa of the scapula into a more vertical position, resulting in increased abduction, rotation, and winging of the scapula.
Due to changes in the position of the scapula, the levator scapulae muscle and superior fibers trapezius muscle begin to strain intensely in an attempt to stabilize her position. Ultimately, this leads to overstrain of the neck and shoulder muscles and the appearance of many trigger points in this area, which is typical for many who work at a desk (or on the couch, with a laptop on their lap).
Shoulder pain, arm numbness, tingling in the upper extremities, as well as trigger points in the neck and back muscles are the consequences of overexertion of the pectoralis minor muscle.
Pectoralis minor syndrome - when nerves and blood vessels are affected
In 50% of cases, it is the pectoralis minor muscle that is the root cause of thoracic outlet compression syndrome (or simply pectoralis minor syndrome). What is it?
Pectoralis minor syndrome is manifested by compression of the nerves and blood vessels located in the anterior part of the shoulder and chest - the brachial plexus, subclavian artery and vein. Pinched nerves and blood vessels necessarily make themselves felt, causing significant physical discomfort.
Symptoms of this syndrome vary depending on the location and degree of compression of the neurovascular bundle and can manifest as:
- pain throughout the entire arm - from the shoulder to the little finger;
- numbness, decreased sensitivity, tingling in the limbs;
- weakness in the hand;
- pallor of the upper limb;
- decreased hand temperature;
- increased pain during movement.
As you can see, the pectoralis minor muscle, or more precisely, its overtension, can cause problems affecting the area of the shoulder joint, neck and arm. But this is only part of the whole picture: as a result of muscular compensation, which passes through the kinetic chain, the negative effects of overexertion of the pectoralis minor muscle can even affect the lower back and pelvic region.
How to relax the pectoralis minor muscle: stretching and trigger point massage
The figures below show the location of the trigger points of the pectoralis minor muscle and a diagram of the reflected pain when pressing these points:
Fortunately, the pectoralis minor responds well to therapy such as massage and/or stretching. However, it is worth noting that it is not so easy to cope with an overstrained pectoralis minor muscle on your own, so the site recommends either contacting a specialist (which, of course, is better) or asking a friend/spouse/relative for help.
Stretches to eliminate pectoralis minor trigger points:
Massage of trigger points of the pectoralis minor muscle:
To massage the pectoralis minor muscle, it is better to contact a specialist who can correctly determine the location of trigger points and effectively influence them. At home, massage can be performed using a tennis ball in a lying position (placing the ball on the floor) or standing (clutching the ball between the wall and the pectoralis minor muscle):
In addition to stretching and massage, try doing exercises aimed at strengthening the antagonist muscles of the pectoralis minor muscle.
Focus on the middle and lower trapezius muscles, diamond-shaped, pay attention to the serratus anterior, infraspinatus muscles, as well as the dorsal deltoids.
Pectoralis Major MUSCLE- the most visible superficial muscle of the chest, lying just under the skin. When it contracts, you can also see where the sternum and ribs are. The action of the muscle is to pull the arm toward the chest, called adduction, and to rotate the arm to rotate the hand inward. The muscle runs horizontally across the chest and is attached to the front of the arm close to where the lower end of the deltoid muscle is attached.
The location of the pectoralis major muscle often causes tension or limits natural movement of the arm and shoulder. However, this muscle is often overlooked as a cause of shoulder pain. Excessive tension in the pectoralis major muscle is often accompanied by weakness in the back muscles, especially the rhomboid muscles. This results in a slouched position in which the shoulders shift forward. Similar disorders are often observed in weightlifters who overload the pectoral muscles by performing chest presses. Fixation of the arm due to a shoulder injury, as well as prolonged periods of emotional tension and stress, can cause stress points in the pectoralis major muscle.
The use of ineffective technique in sports that involve a rowing motion (such as kayaking and canoeing) can lead to the development of stress points. They can also be caused by overload or excessive use of support when skiing or hiking. Holding onto the railing, rather than letting your arms swing naturally while doing monotonous mechanical work, can also limit the use of your pectoralis major muscle.
When points of tension occur in this muscle, pain spreads along the front of the shoulder, covered by the deltoid muscle. It can be felt in the upper part of the chest, and inside the chest, and on the entire inner surface of the arm to the ring finger and little finger. Heart disease can also cause such pain, so it is important to rule out the possibility of heart disease before working on stress points in the pectoralis major muscle, even if you are sure that the source of the pain is the muscle.
The pectoralis major muscle is the muscle that forms the anterior wall of the armpit. Its dense cords and tension points can be felt using the tweezers technique. Sit in a chair with your elbow on the armrest. A space is created between the chest and arm. Place your fingers under the edge of your armpit. This way you can feel the muscle starting from the surface of the chest. Grab the top of the muscle with your fingers. As soon as you move your thumb across the muscle, you will be able to feel the tight bands of the muscle and its painful points. Use your thumb to press on these points. You will feel some soreness, but as the tension in the point is eliminated, it will subside. Work in this way to eliminate tension points and tight bands throughout the pectoralis major muscle and finish releasing it with a stretch.
Stretch 1: The doorway method will lengthen each part of the pectoral muscle. Standing in an open doorway with your forearms firmly planted on the door frames, lengthen your body through your outstretched arms, stretching the chest and shoulder areas. To stretch the upper fibers of the pectoralis major muscle, place your hands at ear level.
Stretch 1 pectoralis major muscle
Stretch 2: To stretch the middle fibers of the muscle, your elbows should be at shoulder level.
Stretch 3: To stretch the lower fibers of the pectoralis muscle, extend your arms as high as possible above your head. You need to concentrate as much as possible on each stretch, holding the position for 20-30 seconds.
