Transversus abdominis
Musculus transversus abdominis
MuscularDeep musclesAbdomenLeft and right
View left in 3D View right in 3D
- What it is
- Deepest flat abdominal muscle, with horizontal fibres running from the inner surfaces of costal cartilages 7–12, the thoracolumbar fascia, the iliac crest and the lateral inguinal ligament forwards into an aponeurosis that ends in the linea alba.
- Function
- Acts like a corset, compressing the abdominal contents and stiffening the lumbar spine just before limb movements.
- Size
- About 20 cm tall, 2–4 mm thick.
- Clinical note
- The TAP (transversus abdominis plane) block places local anaesthetic between it and the internal oblique, where the lower intercostal nerves run.