The multifidus is a deep muscle of the back. It is located underneath the semispinalis muscle and most developed in the lumbar area. Attachments: Has a broad origin – arises from the sacrum, posterior iliac spine, common tendinous origin of the erector spinae, lumbar vertebrae, transverse processes of T1-T3 and articular processes of C4-C7. The fibres ascend 2-4 vertebral segments, attaching to the vertebral spinous processes. Actions: Stabilises the vertebral column. Innervation: Posterior rami of the spinal nerves Blood Supply: Supplied by multiple arteries localised to region along the vertebral column – vertebral, deep cervical, and occipital arteries in the cervical region; dorsal branches of posterior intercostal and subcostal arteries in the thoracic region. By TeachMeSeries Ltd (2025) Fig 1The semispinalis and multfidus muscles. Pro Feature - 3D Model You've Discovered a Pro Feature Access our 3D Model Library Explore, cut, dissect, annotate and manipulate our 3D models to visualise anatomy in a dynamic, interactive way. Learn More Print Article Rate This Article