The core muscles play a fundamental role in stabilizing and moving the body. They are responsible for maintaining correct posture, protecting internal organs, enabling breathing, and performing various movements, such as rotation, flexion, and extension.
The main muscle groups of the trunk include the abdominal muscles, lower back muscles, chest muscles, and back muscles. Each of these muscle groups has specific characteristics and functions that contribute to the health and proper functioning of the body.
In this article, we'll explore in detail the different muscles of the core, their characteristics, functions, and how to strengthen them through specific exercises. Additionally, we'll present illustrative images of the main core muscles to facilitate understanding and visualization of their location in the body.
Main muscles of the trunk: what they are and their functions in the human body.
The main muscles of the trunk are responsible for providing support and stability to the body, as well as aiding in breathing and movement. These muscles are divided into superficial and deep muscles, each with specific functions.
The superficial muscles of the trunk include the rectus abdominis, the external and internal obliques, and the transversus abdominis. The rectus abdominis is responsible for flexing the spine, while the oblique muscles assist in trunk rotation and flexion. The transversus abdominis acts as a "belt" that holds the internal organs in place.
The deep muscles of the trunk include the erector spinae, quadratus lumborum, and intercostal muscles. The erector spinae is responsible for maintaining upright posture and stabilizing the spine. The quadratus lumborum assists in trunk extension, while the intercostal muscles are involved in respiration, aiding in the expansion and contraction of the rib cage.
It's important to keep your core muscles strong to prevent injuries and improve posture. Exercises like planks, sit-ups, and push-ups are great ways to strengthen these muscles and maintain overall health.
Learn about the different types of muscles and their peculiarities in the human body.
The core muscles are essential for the stability and movement of the human body. They support the spine, protect internal organs, and aid in breathing. There are different types of core muscles, each with its own characteristics and specific functions.
The muscles of the trunk can be divided into three main groups: superficial muscles, deep muscles, and abdominal wall muscles. The superficial muscles are the most visible and include the latissimus dorsi, trapezius, and abdominal muscles. They are responsible for movement and stabilization of the trunk.
The deep muscles are responsible for the stability of the spine and the protection of internal organs. They include the transverse abdominis, the quadratus lumborum, and the intercostal muscles. These muscles work together to maintain posture and perform precise movements.
The muscles of the abdominal wall are essential for supporting the internal organs and stabilizing the trunk. They include the rectus abdominis, obliques, and iliopsoas muscles. These muscles are responsible for bending the trunk forward, sideways, and backward.
It's important to keep your core muscles strong and flexible to prevent injuries and improve posture. Exercises like sit-ups, planks, and push-ups are excellent for strengthening core muscles. Additionally, practicing Pilates and yoga can also help improve core flexibility and strength.
Now that you know the different types of core muscles and their characteristics, be sure to include exercises to strengthen them in your workout routine. Your body will thank you!
The meaning of the term “muscular trunk” and its importance for health and physical fitness.
The term "muscle core" refers to the set of muscles located in the trunk region of our body, which includes the abdominal, lumbar, and dorsal muscles. These muscles play a fundamental role in stabilizing the body, maintaining posture, and supporting the spine.
To maintain health and fitness, it's essential to strengthen your core muscles. Strong abdominal muscles, for example, help maintain proper posture and prevent back pain. The lower back muscles are responsible for supporting the body's weight and assisting with spinal flexion and extension.
Furthermore, core muscles are essential for physical activities such as weightlifting, running, and swimming. A well-developed core improves athletic performance and reduces the risk of injury during exercise.
Therefore, it's important to include specific exercises to strengthen your core muscles in your training routine. Exercises like planks, sit-ups, squats, and rows are excellent options for working this area of the body.
Muscle Names: Discover the name of each muscle in the human body.
Core muscles are responsible for supporting and moving the human body. They are located in the trunk region, which includes the chest, back, and abdomen. Knowing the names of the core muscles is essential to understanding how the body works and how we can strengthen them through physical exercise.
Some of the main muscles of the trunk include the pectoralis major, located in the chest region and responsible for movements of pushing and lifting objects; the dorsal, located in the back and responsible for movements of pulling and lifting objects; and the rectus abdominis, located in the abdomen region and responsible for maintaining posture and performing trunk flexion movements.
In addition to these, we also have the external oblique, located on the sides of the trunk and responsible for rotation and inclination movements; the trapezoid, located in the neck and shoulder region and responsible for the elevation and rotation movements of the scapula; and the porthole, located in the lower back and responsible for supporting the body's weight and performing lateral tilt movements.
It's important to remember that all of these core muscles work together to ensure stability and mobility. Therefore, it's essential to include exercises that strengthen these muscles in your fitness routine.
Trunk muscles and their characteristics (with images)
Os trunk muscles are all those muscular structures that cover the thorax and abdomen, providing protection and movement to the thoracoabdominal structures. Most of these muscles are flat and broad, covering a large amount of space and presenting bony insertions at more than two points on the skeleton.
They also have the particularity of overlapping, forming a type of tissue, especially in the anterior abdominal wall, where there is less bone support.
In addition to the flat, broad muscles that literally make up the thoracoabdominal walls, there are also a number of long, narrow muscles, most of which are attached to the spine or located between the ribs.
These powerful muscles have multiple attachments to the vertebrae, keeping the back straight. They also allow flexion, extension, and rotation of the spine.
Classification of trunk muscles
The trunk muscles can be classified according to their insertions into:
– Muscles that are inserted exclusively into the bony structures of the thoracoabdominal region.
– Muscles in which part of the insertions are located in the thoracoabdominal region and part in other anatomical regions (upper limbs, lower limbs or neck).
On the other hand, these muscles can be classified according to the size and arrangement of their fibers into broad and flat muscles, and long and narrow muscles.
Most of the muscles of the thoracoabdominal wall that are part of the trunk wall can be approached more or less easily from the surface, with one exception: the diaphragm.
The diaphragm is a large, flat, wide muscle located within the thoracoabdominal cavity. In fact, it forms the physical boundary between the thorax and abdomen. The diaphragm's function is to allow the chest to move for breathing, as well as to physically separate the abdominal and thoracic compartments.
Muscles that are inserted exclusively into the bony structures of the thoracoabdominal region
These are the muscles of the thoracoabdominal wall. They are arranged in superficial and deep planes, both on the posterior (back) and anterolateral walls of the thoracoabdominal region.
Of all the muscles that attach exclusively to the thoracoabdominal bony structures, the diaphragm deserves special mention, as it is the only one located entirely within the thoracoabdominal cavity. Furthermore, it is the muscle responsible for respiration.
Diaphragm
It is a large, broad, flat muscle that, like a dome, forms the floor of the chest and the roof of the abdomen. It attaches to the dorsolumbar spine, the last costal arch, and the sternum.
It's a powerful muscle, responsible for breathing. It has the distinction of being an involuntary muscle that can be controlled.
Unlike the heart, which beats without the individual's will, the diaphragm performs its function (respiratory movements) automatically; but with the difference that there is some voluntary control over it. This makes it a unique muscle in the entire body.
In addition to its respiratory function, the diaphragm serves as an anatomical boundary and barrier between the structures of the thorax and those of the abdomen, helps maintain the pressure differential between the two compartments of the trunk and also has openings that allow the passage of structures corresponding to the trunk towards the abdomen.
It is, therefore, the most complex and important muscle in the thoracoabdominal region, as it is responsible for breathing, one of the body's vital functions.
Muscles of the posterior region: deep plane
This group includes all the erector spinae muscles, located throughout the spine. Each is thin, of varying length (some are short and some are very long), and they generally form multiple insertions on the vertebral processes.
The erector spinae muscles overlap, like links in a chain, and allow a wide range of flexion and extension movements of the spine.
These muscle groups include the following muscles:
– Interspinous muscles.
– Transverse spinous muscles.
– Intertransverse muscles.
They all run in a cephalocaudal direction and are located in the midline of the back, covered by an intermediate muscular plane.
At chest level, there are no deep muscles outside the midline, this space being occupied by the ribs and intercostal muscles.
In the abdomen, the oblique muscles occupy the deep plane and lie outside the midline. These large, broad, and long muscles line the abdominal wall, inserting them behind the spine, above the last ribs, and below the pelvis.
The abdominal muscles are part of the deep plane of the posterior abdominal wall, as they are covered by other muscular planes. However, in the anterolateral abdominal wall, they become superficial, as they are not covered by other muscular structures.
Muscles of the posterior region: intermediate plane
The intermediate plane is formed by muscles that receive insertions on the scapula. From there, they extend either to other bony structures of the thorax or to the upper limb.
The muscles that insert into the scapulae and vertebral bodies or ribs are as follows:
– rhomboid major.
– Rhomboids minor.
– Serratus anterior.
The rhomboid muscles are inserted into the medial border of the scapula and from there pass to the spinous processes of the dorsal vertebral bodies.
On the other hand, the serratus muscles insert on the same border as the scapula, but in a deeper plane, passing underneath it. Further forward, they are directed forward on the anterolateral wall of the thorax to insert into the costal arches.
The muscles that receive attachments to the abdominal wall and arm are described below.
Muscles of the posterior region: superficial plane
This group is composed of two large muscles: the trapezius and the broad dorsal.
Both muscles occupy the superficial part of the back, overlapping and covering the entire posterior region of the trunk, from the sacrum to the head. Ninety-five percent of their extension is in the trunk, although they have distal insertions in the neck (trapezius) and upper limbs (latissimus dorsi).
Muscles of the intercostal region
They are small, narrow, short muscles located between the ribs, inserted into the upper and lower ribs of each rib.
In each intercostal space there are three intercostal muscles, namely:
– External intercostal.
– Internal intercostal.
– middle intercostal.
The external intercostal muscle is the most superficial of the three and is located across the intercostal space, resting on the costal tubercles at the costochondral junction.
On the other hand, the internal intercostal is the deepest and is located approximately in the anterior two-thirds of the costal arch (does not reach the back). Its fibers generally extend from the sternum to the costal angle.
In the area where the intercostal vessels cross the internal intercostal, this presents a split into two muscular bellies, one internal (internal intercostal) and the other more superficial. The latter is known by some authors as the middle intercostal.
The intercostal muscles are found in the thickness of the thoracic wall, covered in the posterior region by the muscles of the middle and superficial plane of the back and in the anterior region by the pectoral muscles.
Only in the lateral region are they easily accessible, being covered exclusively by subcutaneous tissue and skin. Because of this, this is the preferred location for placing thoracic drainage tubes.
Chest
The muscles of the anterior region are the subclavian (which joins the clavicle to the first costal arch) and the pectoralis major and minor.
The pectoralis minor can be considered a trunk muscle, as it runs from the coracoid process of the scapula to the first three ribs. It is located immediately anterior to the first three ribs, forming the deepest plane of the pectoral region.
Immediately above this and covering it entirely is the pectoralis major. Like the lats and trapezius, 90% of the pectoralis major's muscle mass covers the anterior chest wall, although it also inserts onto the humerus.
These are powerful and robust muscles that not only provide mobility to the arm but also protect the rib cage and support the underlying structures. This is especially true in women, where the mammary gland is closely connected to the pectoralis major through the clavidelopectoral fascia.
Abdomen
The muscles of the anterolateral region of the abdomen are, as already indicated above, the abdominal muscles.
The lateral abdominal wall is composed of three broad, overlapping, and superimposed muscles:
– Greater oblique.
– Minor oblique.
– transverse abdomen.
The greater oblique is the most superficial of the three and covers them completely. Its fibers run from top to bottom and from outside to inside.
Immediately below this is the lesser oblique muscle. Its fibers run in the opposite direction, from bottom to top and back to front. Finally, in the deepest plane is the transverse abdominis muscle, whose fibers run perpendicular to the main axis of the body.
The abdominal muscles receive multiple insertions in the posterior column, the last costal arches (10, 11 and 12) above and the pelvis below. Towards the anterior wall, the aponeurosis of all of them condenses to fuse with the sheath of the rectus abdominis muscle, located alone in the midline of the anterior wall.
The rectus abdominis is broad, flat, and thick. It occupies the midline and has proximal insertions on the tenth costal arch and the xiphoid process, while its distal insertions are located on the pubic symphysis.
In the midline, the left and right rectus abdominis anterior merge into an aponeurotic thickening known as the linea alba.
Muscles of the perineum
These are small, short, and strong muscles that make up the floor of the pelvis. They are classically described as a separate region (perineum), but functionally, they constitute the floor of the entire abdominal cavity. Therefore, they should be mentioned when counting the muscles of the trunk.
This region includes the following muscle groups: superficial plane, middle plane, and deep plane.
Surface plane
– External anal sphincter.
– Superficial transverse of the perineum.
– Ischiocavernosus.
Bulbocavernosus.
– Muscular constrictor of the vulva.
Middle plane
– Deep transverse perineum.
– urethrovaginal sphincter.
– Urethral compressor.
Deep plane
– Levator ani.
– Ischiococcygeus.
– Pubococcygeus.
Muscles partially inserted into the thoracoabdominal region and other anatomical regions
Most of these muscles are located in the posterior region of the trunk, forming the intermediate muscular plane in the dorsal region of the thorax.
They are powerful muscles that connect the upper extremities to the trunk, so that they are inserted into the thoracoabdominal bony structures and the axial skeleton.
These muscles include the following:
– Infraspinatus.
– Supraspinatus.
– Main round.
– Smaller round.
– Subscapularis.
References
- Gardner-Morse, M., Stokes, IA, & Laible, J.P. (1995). Role of muscles in lumbar spine stability during maximal extension efforts.Journal of Orthopedic Research , 13
- Anraku, M. & Shargall, Y. (2009). Surgical conditions of the diaphragm: anatomy and physiology.Thoracic surgery clinics , 19
- Issa, FG and Sullivan, C.E. (1985). Respiratory muscle activity and thoracoabdominal movement during acute episodes of asthma during sleep.American Review of Respiratory Disease , 132
- Sirca, A. and Kostevc, V. (1985). Fiber type composition of the thoracic and lumbar paraspinal muscles in man.Journal of Anatomy , 141 , 131.
- Collis, J. L., Kelly, T. D., & Wiley, A. M. (1954). Anatomy of the crura of the diaphragm and surgery of hiatal hernia.Chest , 9 (3), 175.