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.
TrA arises from more than one origin;
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,
Innervated by lower five intercostal nerves, subcostal nerve, ilioinguinal L1 and iliohypogastric L1
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.
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
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
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.
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.
- Selkow NM, Eck MR, Rivas S. Transversus abdominis activation and timing improves following core stability training: a randomized trial. International journal of sports physical therapy. 2017 Dec;12(7):1048.
- AnatomyOnlineCourse. Clinician Education: Transversus abdominis - AnatomyOnlineCourse. Available from: http://www.youtube.com/watch?v=S6hqhnSM-MU[last accessed 25/4/2020
- Lynders C. The Critical Role of Development of the Transversus Abdominis in the Prevention and Treatment of Low Back Pain. HSS Journal®. 2019 Oct 1;15(3):214-20.
- Oh YJ, Park SH, Lee MM. Comparison of Effects of Abdominal Draw-In Lumbar Stabilization Exercises with and without Respiratory Resistance on Women with Low Back Pain: A Randomized Controlled Trial. Medical Science Monitor: International Medical Journal of Experimental and Clinical Research. 2020;26:e921295-1.
- Physical Therapy Nation. Clinician Education: How To Teach Proper Transverse Abdominis Contraction. Available from: http://www.youtube.com/watch?v=p8O04WLXFt8[last accessed 25/4/2020