Trunk (thorax, abdomen, back)

Iliocostalis Thoracis (Thoracic Part)

Musculus iliocostalis thoracis

Origin

Angle of the 7th through 12th ribs (medial side)

Insertion

Angle of the 1st through 6th ribs and the transverse process of C7

Function

Extension and, unilaterally, lateral flexion of the thoracic spine

Innervation

Dorsal rami of the thoracic spinal nerves

Movement & chain

Forms the bridge between iliocostalis lumborum and cervicis, providing a continuous line of pull along the entire spine during postural control.

Palpation

Palpable along the rib angles about 4–6 cm lateral to the thoracic spinous processes.

Clinical

Extends and laterally flexes the thoracic spine; marked protective spasm in rib fractures and thoracic vertebral compression.

Segmental innervation

Dorsal rami of the thoracic spinal nerves, segmental per level.

In clinical practice

Ergonomic patient repositioning (log-roll technique in spinal trauma) and pressure offloading; maintain neutral spinal alignment in bedridden patients.

Region in the model

Trunk (thorax, abdomen, back)