Anatomy of the Abdomen and Why Core Strength is Important

Anatomy of the Abdomen and Why Core Strength is Important

Anatomy of the Abdomen

Understanding a little about the anatomy of the abdomen, will help you to know which muscles you are working as you exercise the abdominal area. You don’t need to remember the names of every muscle within the abdomen, but just knowing where they are is good enough.

anatomy of the abdomen

The human abdomen is the area of the body between the thorax and the pelvis, and the human abdominal muscle group is made up of various muscles, as follows:


Rectus Abdominus

The rectus abdominus is the largest of the abdominal muscles and is frequently referred to as the “six-pack”.  These muscles (and there are two of them) are long and flat and extend from the front of the ribs down to the front of the pelvis.  The rectus abdominus is crossed by three tendinous intersections of muscle called the linae transversae. They are required for spinal flexion and assist with breathing.  They also help to keep all internal organs intact and and create intro-abdominal pressure which aids the body when lifting heavy objects.

Transversus Abdominis

The transversus abdominis muscle lies deep inside the abdomen, running between the hips and the ribs.  It is flat and triangular in shape, and its fibres run horizontally.  This muscle provides stability of the body’s trunk in lateral flexion (ie. when bending to the side) and it supports the breathing as it acts as a force upon the lungs during exhalation.


The pyramidalis muscle is small and triangular in shape, being located in the lower part of the abdomen, but in front of the rectus abdominis.

I assure you that understanding the anatomy of the abdomen will help with your exercise program and in your quest to gain a six-pack.

The abdomen also has side muscles, known as the oblique muscles.  There are two on each side of the body, the external oblique muscles and the internal oblique muscles.

External Oblique Muscle

The external oblique muscle is the largest and outermost of the three flat muscles situated on the anterior and lateral part of the abdomen and this pair of muscles lies closer to the surface than the internal obliques. They reach from the bottom of the ribs to the front of your pelvis in a “V” shape and are not usually visible in most humans, due to levels of body fat and the fact that they are relatively small in size.

The external oblique muscles help in trunk flexion and trunk rotation. They also support the contents of your abdomen and support exhalation.

The external oblique muscles are responsible for pulling the chest downwards, and for compressing the abdominal cavity.  They are also connected with both rotation and flexion of the vertebral column.

Internal Oblique Muscle

The internal oblique muscle lies just beneath the external oblique muscle and just over the top of the transverse abdominal muscle.

It performs two major functions:

  • It helps to support the breathy by forcing exhalation.  As the internal oblique muscles contract, they compress all of the organs within the abdomen, thus pushing them up towards the diaphragm.  This in turn intrudes into the chest cavity and reduces the volume of the lungs filled with air, forcing exhalation.
  • It acts with the external oblique muscles of the opposite side of the body as it contracts, to rotate and assist the trunk to bend to the side, by pulling the rib cage and midriff area down towards the hip and lower back, of the same side.

Why  Core Strength is Important

Your abdominal muscles provide support to your trunk and are an important part of your body’s core.

It is good to know why core strength is important and to include core muscles in your exercise routines.  Core strength is necessary for good posture and is essential in the prevention of back pain. Your core muscles help to stabilize your spine and pelvis, and are instrumental for a healthy breathing function and organ support.

Other muscles of the core include your lower back muscles, hip muscles (flexors, adductors), erector spinae and gluteus muscles.

This insight into understanding the anatomy of the abdomen and why core strength is important, should greatly assist you when working on your abdominal muscles to reveal your much sought after toned abs or six-pack!