There are six different abdominal muscles of the anterior abdominal wall; the rectus abdominus, two external oblique muscles on each side, two internal oblique muscles on each side and the transverse abdominus muscle.
These muscles extend from various places on the ribs to various places on the pelvis and provide movement and support to the trunk.
Rectus Abdominis Muscle
The rectus abdominus is the muscle that is generally referred to as a “six packâ€. Although many refer to this as the lower ab and upper ab it is actually one long muscle. It is located between the ribs and the pubic bone at the front of the pelvis. The main purpose of this muscle is to move the body between the rib cage and the pelvis.
External Oblique Muscle
There are 2 external oblique muscles located on each side of the rectus abdominus. These muscles allow your body to twist, but to the opposite side of whichever muscle is contracting. So, to twist to the left, you are contracting the right external oblique muscle.
Internal Oblique Muscle
There are also 2 internal oblique muscles located just inside the hip bones. These muscles are also used to aid in twisting the body, howe