Muscle guide · Core and trunk

Transversus abdominis

Also called TVA, deep core muscle, corset muscle

The transversus abdominis is the deepest of the three flat abdominal muscles. Its fibres run horizontally around the waist, like a corset, from the back and sides to the midline seam at the front.

It squeezes the belly to breathe out hard, cough and bear down, and it switches on a fraction before you move an arm or leg, raising the pressure inside the abdomen along with the diaphragm.

5 exercises5 with 3D demos14 sourcesUpdated 17 October 2026

Where the transversus abdominis is and what it does

Shaded: the abs area. It marks the region, not the exact outline of the transversus abdominis.

Starts at (origin): The inside of the lower rib cartilages, the deep fascia of the low back, the top of the hip bone and the groin ligament.Lower six costal cartilages, thoracolumbar fascia, iliac crest and lateral inguinal ligament (sources differ on the ribs)
Attaches to (insertion): The midline seam of the belly and, at the bottom, the pubic bone.Linea alba; conjoint tendon to the pubis
What it does: Squeezes the belly: blowing out hard, coughing, bearing down.Compression of the abdominal contents
Switches on just before a limb moves, stiffening the trunk.Anticipatory (feed-forward) postural activity
With the diaphragm, raises the pressure inside the abdomen.Intra-abdominal pressure with the diaphragm
Nerve supply: Thoracoabdominal nerves (T7 to T12), plus the iliohypogastric and ilioinguinal nerves (L1) to its lower part.

Sources 1, 2, 3

Exercises for the transversus abdominis

A plank with the opposite arm and leg lifted produced the greatest activity in a fine-wire EMG study; side bridges and bird dogs were tested alongside. Gently drawing in the lower belly while breathing normally is a teaching step in low-back rehabilitation.

Forearm plank demonstrated on the 3D figure

3D demoForearm plankIntermediate · No equipment

Side plank demonstrated on the 3D figure

3D demoSide plankIntermediate · No equipment

3D demoBird dogBeginner · No equipment

Knee plank demonstrated on the 3D figure

3D demoKnee plankBeginner · No equipment

Knee side plank demonstrated on the 3D figure

3D demoKnee side plankBeginner · No equipment

Problems linked to the transversus abdominis

Delayed timing in low back painMixed evidence

In lab studies the muscle switched on later in people with low back pain than in people without. Later research questioned how special this is: the muscle tends to work as part of a whole-trunk pattern rather than as an isolated stabiliser.

Sources 5, 10

Myths worth dropping

Each grade rates the evidence for the correction.

You must draw in your belly button before every liftMixed evidence

In a modelling study, bracing the whole abdominal wall raised spine stability about a third; the transversus contributed a tiny fraction, and the authors found no mechanical case for hollowing. Under a sudden load, hollowing did not reduce trunk motion while bracing did, at the cost of more spinal compression.

For chronic back pain, exercises that train the deep muscles beat minimal treatment but were no better than other exercise in a Cochrane review. After a first episode, one small trial found fewer recurrences with specific training, so it can help; it is not the only route.

Sources 8, 9, 11, 12

Routines that train it

Beginner core workout

A 15-minute beginner core workout on the floor: dead bugs, bird dogs, knee planks, side planks and curl-ups.

15 minBeginner6 movesNo equipment

Pelvic floor exercises

Pelvic floor exercises in 5 minutes: slow holds and quick squeezes, three times a day, with how to find the right muscles.

5 minBeginner2 movesNo equipment

Questions people ask

What does the transversus abdominis do?

It squeezes the belly to breathe out hard, cough or bear down, and switches on just before a limb moves to stiffen the trunk, together with the diaphragm.

Should I draw in my belly button when I lift?

There is no evidence healthy lifters need to. In lab studies, bracing the whole abdominal wall stiffened the spine more than hollowing did.

How do you train the transversus abdominis?

Planks, side planks and bird dogs all work it; a plank with the opposite arm and leg lifted produced the most activity in a fine-wire EMG study.

Muscles it works with

Sources

Anatomy and movement education, not a diagnosis or treatment plan. If you have pain that follows an injury, is severe or getting worse, or comes with numbness, weakness or swelling, get it assessed. Health disclaimer.