Anatomy & Organs

Abdominal muscles – structure, function & diseases


Together with the back and chest muscles, the abdominal muscles form the muscular corset of the torso. They enable various torso movements, support breathing , protect the organs in the abdominal cavity and also help with excretion via abdominal pressure. The most common symptoms include strains and hernias , as well as herniated discs, which often occur as a result of poorly trained abdominal muscles.

What are abs?

The abdominal muscles (from Latin: abdomen = abdomen) together with the muscles of the back and chest form the core muscles. They are necessary to bend the trunk forward or to the side. In addition, they are used for all rotational movements of the torso.

They are involved in the exhalation and support the excretion via the abdominal press by increasing the pressure inside the abdomen by tensing them. Functional abdominal muscles are of crucial importance for an upright and therefore healthy posture.

As a direct antagonist (opponent) to the muscles of the back or spine, well-developed abdominal muscles avoid a hollow back and in this way efficiently protect the intervertebral discs and the nerve structures emerging from the spinal canal.

In contrast to the muscles of the extremities of the arms and legs, the abdominal muscles originate in the skeleton and are therefore counted among the skeletal muscles.

Anatomy & Structure

From an anatomical point of view, the abdominal muscles are divided into a superficial and a deep part. The superficial muscles form the anterior and lateral abdominal wall.The front (also middle) abdominal muscles are the straight abdominal muscle (M. rectus abdominis) and the pyramidal muscle (M. Pyramidalis), the lateral part consists of the transverse abdominal muscle (M. transversus abdominis) and – on the left and right – of the External and internal oblique muscles (M. obliquus externus and internus abdominis respectively).

The lateral abdominal muscles terminate at the midline of the abdomen (median line) in tendon plates, which together form a sheath in which the rectus abdominis lies. This line (also known as the rectus sheath) runs from the breastbone down to the pubic symphysis. The deep-lying part of the abdominal muscles is formed by the square lumbar muscle (M. quadratus lumborum), some classifications also add the M. iliopsoas.

Function & Tasks

All abdominal muscles work together to ensure a physiological and therefore healthy posture and an upright gait. In addition, they make an important contribution to stable fixation and protection of the abdominal organs. The main function of the rectus abdominis is to bend the trunk forward or, if the upper body remains in a fixed position, to raise the legs.

In addition, the muscle is involved in abdominal compression. A good training condition of the rectus abdominis is visually evident from the colloquial “six pack”. The oblique abdominal muscles are particularly important for the main task of the abdominal muscles, which is to effectively tense the torso and in this way to protect the sensitive spine from one-sided loads or external influences. The oblique part is also needed if you want to turn the trunk to the right or left or tilt it sideways.

The oblique abdominal muscles also increase the intra-abdominal pressure due to their tension and are thus involved in the abdominal press. The transverse abdominal muscle supports the straightening of the pelvis and also shapes the waist. The task of the quadratic pectoral muscle, which is part of the posterior abdominal wall, is to tilt the trunk sideways. It also supports exhalation and inhalation through its stabilizing function.

Diseases & Ailments

The classic strain is one of the most common complaints in the area of ​​the abdominal muscles. Here, the muscle fibers are stretched beyond the normal extent by abrupt, non-physiological movements. The smallest structures react with cracks, which are sometimes perceived as very painful by those affected when they move.Often the healing of a pulled abdominal muscle is a comparatively longer process, since the abdominal muscles are practically always in use due to their holding and supporting function, even in normal everyday life and for this reason can hardly be spared. Weak abdominal muscles can also promote the occurrence of a hernia, in which parts of the intestines bulge outwards through a gap in the abdominal wall and usually have to be surgically put back in place.

In terms of symptoms, however, abdominal muscles that are not sufficiently trained have the greatest relevance for the spine : A muscular imbalance – weak abdominal muscles and strong back extensors – can lead to a hollow back , which can damage the intervertebral discs and the nerves emerging from the spinal canal in the long term.

In many cases, the classic herniated disc is caused by insufficient training of the abdominal muscles in connection with poor or one-sided posture. In concrete terms, this means that abdominal muscle training is one of the most important treatment pillars in conservative therapy.

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Hello! I am Lisa Newlon, and I am a medical writer and researcher with over 10 years of experience in the healthcare industry. I have a Master’s degree in Medicine, and my deep understanding of medical terminology, practices, and procedures has made me a trusted source of information in the medical world.