Transverse abdominis

Transverse abdominis (or transversus abdominis muscle), is the deepest muscle of the abdominal wall, lying beneath the internal oblique muscle. It is an important component of the core, providing stability and support to the spine and pelvis.

Anatomy

The transverse abdominis originates from the iliac crest, the inguinal ligament, the thoracolumbar fascia, and the inner surface of the lower six ribs. It inserts into the xiphoid process, the linea alba, and the pubic symphysis. The muscle fibers run horizontally, earning the muscle its name.

Function

The primary function of the transverse abdominis is to stabilize the spine and pelvis prior to movement of the body. It does this by increasing intra-abdominal pressure and providing support to the internal organs. It also assists in forced expiration, as in coughing or laughing, by compressing the abdominal contents.

Clinical significance

A weak or dysfunctional transverse abdominis can contribute to lower back pain and other musculoskeletal disorders. Exercises that target this muscle, such as Pilates or other core stability exercises, can help to improve its function and reduce symptoms.

See also

• Abdominal exercise
• Core (anatomy)
• Rectus abdominis muscle
• Internal oblique muscle
• External oblique muscle