Erector spinae
Latin: M. erector spinae sinistra
Location: Back
Paired structure: one on the left and one on the right side of the body.
View the erector spinae in 3DOrigin
Sacrum, iliac crest, lumbar spinous processes via the erector spinae aponeurosis.
Insertion
Ribs, spinous and transverse processes throughout the thoracic and cervical spine, and the mastoid process (via longissimus capitis).
Action
Extends and stabilises the vertebral column ipsilaterally — the great posture muscle keeping the trunk upright against gravity; unilateral action side-bends and rotates the spine.
Nerve supply
Posterior (dorsal) rami of spinal nerves at every level.
Blood supply
Segmental branches of the posterior intercostal, subcostal and lumbar arteries.
Clinical relevance
Disc herniations compress spinal nerve roots and cause radicular leg pain, whereas muscle strain and facet-joint irritation (dorsal-ramus territory) produce local paraspinal spasm — the commonest 'back spasm'.
Educational anatomy reference, not medical advice. About this content.