Transversus Abdominis

Original Editor - Khloud Shreif

Top Contributors - Lucinda hampton, Khloud Shreif, Kim Jackson, Candace Goh, Joao Costa, Wanda van Niekerk and Oyemi Sillo

Description

Transverse abdominis (TrA) is a flat thin sheet of abdominal muscle presented under internal abdominal obliques, on the anterolateral abdominal wall, its fibers run transversely perpendicular to linea alba. TrA is one of the main core muscles, keep the support of the lumbopelvic region.

Origin

TrA arises from more than one origin;

transversus abdominis

Lateral third of inguinal ligament and associated iliac fascia, anterior two-third of the iliac crest, thoracolumbar fascia, and inner surface of lower six costal cartilage and their ribs(7-12)

Insertion

It's fibers run transversely from the lateral abdominal wall anteriorly to the midline inserts into linea alba, xiphoid process, and symphysis pubis by rectus sheet, the inferior tendinous fibers attach with fibers from the interior obliques forming the conjoint tendon which attaches to pubic crest and pectinal line,

Nerve

Innervated by lower five intercostal nerves, subcostal nerve, ilioinguinal L1 and iliohypogastric L1

Artery

Receive blood supply from the lower posterior intercostal and subcostal arteries, superior and inferior epigastric arteries, superficial and deep circumflex iliac arteries, posterior lumbar arteries.

Function

With other abdominal muscles, TrA helps to maintain abdominal tension and support abdominal viscera, increase intraabdominal pressure that is helpful in forceful expiration, coughing, defecation.

It's an important core muscle that supports lumbopelvic during our movement.

Unilateral action: ipsilateral trunk rotation

Clinical Relevance

Transverse abdominis is a deep abdominal muscle and an important core muscle inhibition or inadequate activation contributes to low back pain, lumbar instability

Trigger point: abdominal trigger points may be a primary cause of abdominal pain or an associated /secondary condition.

The costal attachment of TrA refers pain to the anterior abdomen, xiphoid process it's local pain.

The suprapubic attachment refers pain inferiorly and medially. If there is a trigger point patient may present with distressing cough

Palpation

In crook lying position, find the ASIS, and move two inches toward the midline then one inch inferior apply light pressure. When the muscle is contracted you will feel muscle tension popping under your finger.

Treatment

Drawing in technique is the most effective technique to activate and strengthen TrA as well as diaphragm it has a positive effect also on LBP and respiratory pattern. Exercise be graduated from maintaining static contraction to be involved in more dynamic and functional activities, and apply it with other core exercises.

When applying technique you shouldn't squeeze buttocks, flatten the back, or bear down, pressing back into the surface activate superficial abdominal muscles with TrA, and pelvic tilting activates the rectus abdominis also.

correct abdominal draw in

relaxed position

rectus over activity

Resources

Lumbar Motor Control Training