The levatores costarum are twelve pairs of small fan-shaped muscles on each side of the thoracic spine, arising from the transverse processes of C7-T11 and inserting on the outer surface of the rib immediately below (levatores costarum breves). The lower four muscles may also send a slip to the rib two levels below (levatores costarum longi). They span the costovertebral angle and represent the homologues of the intertransversarii and correspond embryologically to the same dorsal ramus musculature.
| Origin | Tips of the transverse processes of C7 and T1 to T11 (twelve muscles on each side) |
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| Insertion | Outer surface of the rib below the vertebra of origin, between the tubercle and angle |
| Nerve Supply | Posterior rami of thoracic spinal nerves (C8-T11) |
| Blood Supply | Posterior intercostal arteries; Lateral branches of dorsal spinal arteries |
| Actions | Elevation of the ribs (assists inspiration); Extension, lateral flexion, and rotation of the thoracic spine |
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The levatores costarum are not commonly discussed clinically but contribute to both thoracic spine mobility and rib elevation during deep inspiration. Trigger points in these muscles may contribute to posterior thoracic pain that mimics facet joint or costovertebral joint pain. They are identified during posterolateral thoracotomy and thoracoscopic procedures as they fan across the costovertebral angle. Their innervation by posterior rami distinguishes them from the intercostal muscles which receive anterior rami supply.
Palpated in the costovertebral angle between the transverse processes and the rib angle, approximately 3-5 cm lateral to the thoracic spinous processes. Best assessed with the patient prone.
Myofascial trigger points within the levatores costarum contribute to posterior thoracic and inter-scapular pain, often confused with costovertebral joint or thoracic facet pain, treated with dry needling, massage, and thoracic mobility exercises.
