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

The transversus abdominis (TrA) muscle is the deepest of the 6 abdominal muscles. It extends between the ribs and the pelvis, wrapping around the trunk from front to back. The fibers of this muscle run horizontally, similar to a back support belt. In this way, along with providing postural support, the transverse abdominal muscle helps to contain and support the organs located inside the trunk.

TrA is one of the main core muscles that support of the lumbopelvic region.

Image: Transversus abdominis muscle (highlighted in green) - anterolateral view

Origin and Insertion

TrA arises from:

• Lateral third of inguinal ligament and associated iliac fascia,
• Anterior two-third of the iliac crest,
• Thoracolumbar fascia
• Inner surface of lower six costal cartilage and their ribs(7-12)

Inserts onto the

• Linea alba
• Aponeurosis of internal abdominal oblique muscle
• Pubic crest
• Pectinal line of pubis.

Nerve and Artery

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.

Function

This important muscle is responsible for maintaining proper placement of the abdom­inal contents as well as helping support the lower back.

With the other abdominal muscles, TrA helps to:

• Maintain abdominal tension and support abdominal viscera
• Increase intraabdominal pressure that is helpful in forceful expiration, coughing, defecation.
• Support lumbopelvic during our movement, in concert with other core muscles.
• 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 and lumbar instability

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

• The costal attachment of transversus abdominis 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.

Weakness of Transversus Abdominis

Typical signs of a weak transversus abdominis are toned abdominals above the navel but a bulge below it. The client may experience: an inability to hold in the stomach after a large meal or when gassy; low back fatigue after pro­longed standing or walking.

Physiotherapy Exercises

Drawing in technique is the most effective technique to activate and strengthen TrA.

• Basic Abdominal draw-in maneuver. Lay on your back, with knees bent and feet flat on the floor. Place your fingers on the muscles just below your belly button then contract those muscles by pulling them down and away from your fingers. ie pull the belly-button down toward the floor without holding your breath during this movement. Keep your upper-abdominal muscles, back muscles, and hip muscles relaxed. Hold this position for 5 seconds making sure you continue to breathe. The point of this direct transverse abdominis exercise is to fire the transverse abdominis without firing the rectus abdominis muscle.

Exercise be graduated from maintaining static contraction to be involved in more dynamic and functional activities, and apply it with other core exercises.

correct abdominal draw in

relaxed position

rectus over activity

The side plank (side bridge) and regular plank are arguably the best exercises for activating the TVA indirectly. The 2 minute video below shows how to exercise TrA

See also Lumbar Motor Control Training

Resources

This 3 minute video is a good summary of the transversus abdominis muscle.