The levatores costarum are 12 pairs of small fan-shaped muscles in the posterior thorax, each arising from a transverse process and inserting onto the rib below. The levatores longi, present only at the lower four levels, bridge two rib levels. They function as secondary inspiratory muscles and deep rotators of the trunk. Their position between the transverse processes and ribs makes them relevant in costovertebral joint biomechanics.
| Origin | Transverse processes of C7 and T1-T11 (one per level) |
|---|---|
| Insertion | Levatores breves: outer surface of the rib immediately below; Levatores longi (lower 4 pairs): outer surface of the rib two levels below |
| Nerve Supply | Posterior rami of corresponding thoracic spinal nerves |
| Blood Supply | Posterior intercostal arteries; Deep cervical artery (upper levels) |
| Actions | Elevate the ribs during inspiration; Assist ipsilateral trunk lateral flexion; Assist contralateral trunk rotation |
|---|
The levatores costarum are implicated in posterior thoracic pain syndromes, particularly at costovertebral junctions. They become active in respiratory distress as accessory muscles of inspiration. Posterior thoracic injection techniques for costovertebral joint pain target these muscles and their transverse process origins. Trigger points in the levatores costarum refer pain along the corresponding intercostal nerve distribution.
Deep palpation lateral to the thoracic spinous processes and medial to the paraspinal erector spinae mass may identify tenderness at individual costovertebral levels. Not directly palpable as discrete muscles.
Traction injury at the levator costae origin or insertion producing posterior thoracic pain reproduced by deep inspiration and ipsilateral rotation, localised to a single costovertebral junction.
