External abdominal oblique muscle
Internal abdominal oblique muscle
The internal abdominal oblique is part of the anterolateral abdominal muscles, a group that also includes the transversus abdominis, external abdominal oblique, rectus abdominis, and pyramidalis muscles.
This paired muscle is situated between the rectus abdominis and transversus abdominis muscles and plays a role in the flexion and rotation of the trunk.
|Internal abdominal oblique muscle|
|Origin||Anterior two thirds of the iliac crest;
|Insertion||Inferior margins of the ribs 10-12;
|Innervation||Intercostal nerves 6-11;
Subcostal nerve (T12)
|Functions||Flexion of the trunk;
Lateral flexion of the trunk;
Rotation of the trunk.
Origin and insertion
The internal oblique muscle originates from the anterior two-thirds of the iliac crest and the thoracolumbar fascia. Its fibers diverge over the side of the trunk and insert along the structures of the midline, including the inferior margins of ribs 10-12, the linea alba, and the pubic crest.
The internal abdominal oblique is innervated by intercostal nerves 6-11 and the subcostal nerve.
Bilateral contraction of the internal oblique muscle aids in the flexion of the trunk and increasing intraabdominal pressure.
Learn this topic even more efficiently with this trunk wall muscle anatomy reference chart.
An Overview of the Internal Oblique Muscle
Muscles That Act On Abdominal Wall
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