What Are the Pectorals?
Muscles of thorax, located on the bottom wall of the thorax and connected to the forelimb muscles, have superficial and deep muscles, each divided into anterior and posterior muscles.
- Chinese name
- Pectoral muscle
- Foreign name
- muscles of thorax
- Alias
- Pectoralis major
- Make up
- Upper chest muscles
- Muscles of thorax, located on the bottom wall of the thorax and connected to the forelimb muscles, have superficial and deep muscles, each divided into anterior and posterior muscles.
Anatomy of the pectoral muscle
- The superficial pectoralis muscle is also called the descending thoracic muscle from the sternal stem to the humerus condyle. The horse is clearly visible on the anterior surface of the chest; , Horses, etc. can be extended to the forearm. The superficial pectoralis can adduct the forelimbs. The deep pectoralis muscles begin on the ventral side of the sternum, adjacent to the costal cartilage, and in front of the abdominal wall.
Composition and function of pectoral muscles
- The pectoralis muscle (thoracicmuscle) is divided into upper pectoralis muscles and thoracic extensor muscles.
- Can be divided into upper thigh muscles and thoracic extrinsic muscles. The upper chest muscles are shown in the table below.
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- The chest wall intrinsic muscles are mainly intercostal muscles. The intercostal muscles seal the intercostal space and are divided into three layers, namely the intercostal muscle, the intercostal muscle, and the intercostal innermost muscle. The starting point of the intercostal external muscle is attached to the lower edge of the previous rib, and the fibers are forward and downward, and stop at the upper edge of the next rib. The internal intercostal muscle is attached to the deep side of the external intercostal muscle. The starting point is attached to the upper edge of the next rib. The muscle fibers are inclined forward and upward and stop at the lower edge of the previous rib. The innermost intercostal muscle is located in the middle part of the intercostal space and the deep side of the intercostal inner muscle. There are intercostal blood vessels and nerves passing between the two. The fiber direction is the same as the intercostal inner muscle. Intercostal muscles are innervated by the 1st to 11th intermuscular nerves.
- The intercostal nerve, the anterior branch of the upper 11 pairs of thoracic nerves are called intercostal nerves, and the anterior branch of the 12th pair of thoracic nerves are called subcostal nerves, all accompanied by blood vessels of the same name. The lower 6 pairs of intercostal nerves penetrate the intercostal space through the deep side of the costal arch into the abdominal wall. The intercostal nerve is directly attached to the inner thoracic fascia and parietal pleura at the front and back of the intercostal space.
- Intercostal arteries and veins, intercostal arteries are divided into posterior intercostal arteries and anterior intercostal arteries. The former is a branch of the thoracic aorta, and the latter is the branch of the internal thoracic artery in the 1st to 6th intercostal space or the myoiliac artery in the first. Branches of 7-9 intercostal space, the two coincide at the front of intercostal space.
- The posterior intercostal artery runs in the middle of the superior and inferior ribs and the deep surface of the intrathoracic fascia at the back of the intercostal space, and in the middle of the intercostal space along the intercostal groove between the intercostal inner muscle and the intercostal innermost muscle. Anastomosis with anterior intercostal artery. The blood vessels and nerves are arranged from the top down to the veins, arteries and nerves, to the front of the intercostal space, and they run inside the intercostal inner muscle.
- Intercostal veins include anterior and posterior intercostal veins, which accompany arteries of the same name, and veins are located above the arteries. The posterior intercostal vein is directly injected into the odd vein or indirectly via the semi-odd vein and the para-hemi-venous vein; the anterior intercostal vein is injected into the intrathoracic vein. The first and second pairs of intercostal arteries come from the costal neck shaft of the subclavian artery, and the third to eleventh pairs of intercostal arteries originate from the thoracic aorta.
- The pectoralis fascia starts from the clavicle and the sternum. The surface of the great foot muscles is connected downward to the abdominal wall fascia and outwards to the back fascia. The pectoralis fascia and the psoas muscle can be bluntly separated, while the pectoralis major and pectoralis fascia remain intact. The thickness of the pectoralis fascia is about 0.2nun to 1.12unn. In the upper part of the pectoralis fascia, fine fibrous tissue can be seen to connect the pectoralis fascia and the deep layer of the superficial fascia of the breast. In the middle and lower part of the foot muscle fascia, obvious vascular nerve perforating branches penetrate the foot muscle fascia into the breast tissue. At the fourth intercostal level, it can be seen that the transverse fibrous space connects the pectoralis fascia and the nipple, so that the posterior breast space is turned forward here. The medial and lateral sides of this fibrous space are fused with the medial and lateral ligaments of the breast, respectively.
Breast muscle exercises
- In barbell press (bench press) bench press, factors such as barbell weight, grip style, grip distance, lifting angle, lifting speed, and group frequency affect the pectoralis major muscle training effect. The position of the lever lifting must be placed on the pectoral muscles being trained (from the bottom to the transverse septum and from the top to the collarbone). The chest should be from bottom to top and wide to narrow, that is, the lower chest (recumbent recline) and the mid chest (Recumbent position), after training the upper chest (recumbent reclining), first wide grip, then the middle grip, then narrow grip to practice the width of the chest muscles, narrow grip to practice the height (thickness) of the chest muscles. As for the bench press bench, the oblique bench press (20o ~ 30o) and the bench for bench press (30o ~ 45o) can raise the upper chest to a horizontal position and make the barbell act on the upper chest muscles vertically.
- Bench press breathing: Inhale when exerting force, which can increase the amount of myoglobin stored in oxygen and muscle glycogen for twins, and enlarge the muscle capillaries, which is conducive to exertion. If you exhale during exertion, there will be hypoxia, insufficient muscle glycogen supply, muscle strength will decrease, and the number of muscle fibers involved in exertion will decrease; in addition, insufficient muscle glycogen "burning" will produce more Lactic acid makes muscles sore and fatigued. Therefore, the correct breathing method of bench press is to inhale when the barbell is pushed up and exhale when the barbell is lowered. The speed of the bench press: fast contraction (1 to 2s) and slow extension (2 to 4s) The method of force is inconsistent with Wade's law of slow continuous tension (forced contraction time 4s, reduction and extension time 2s). The author's experience is that the reduction time is the same as the contraction and lifting time (2 ~ 3s), and the lifting speed is too fast. Or it is too slow, which means that the weight is not suitable. Inclined barbell bench press is essential for the development of muscle masses throughout the upper body. It can not only improve the fullness of the upper part of the chest muscles, but also directly stimulate the front of the deltoid muscles. In fact, there is no other way to increase the muscle mass and separation of the entire upper chest and shoulders other than the inclined barbell bench press, and there is no better way to increase the width of the shoulder. The inclined barbell bench press is a compound Movement can stimulate multiple muscle groups at the same time, so it should be arranged at the beginning of chest training. Since deltoid muscles are inevitably irritated during sloping bench presses, make sure to warm up fully. German bodybuilding heavyweight champion Max Ruhe suggested starting with a group of about 30 times. If this is the first training exercise, do 10 to 12 sets of pyramidal weight gain, and the last set to do 3 to 4 times, plus some forcings. If you start with a sloping bench press, arrange it in the second place, and do 6 to 8 groups, 6 to 8 times per group. During the bench press, the tighter the lever is held, the tighter the entire body is, the more you feel The lighter. By tightening your hips, back, and shoulders, your body is more stable and easier to maintain weight control.
- While practicing the pectoralis major, the exercise of the upper arm's triceps should be strengthened. Without a developed triceps, it is impossible to bench press a heavy barbell, and the pectoralis major can not be trained. Generally, the weight of the bench press should be three times the weight of the triceps.