Audio LecturePro Feature Spinalis 0:00 / 0:00 1x 0.25x 0.5x 0.75x 1x 1.25x 1.5x 1.75x 2x The spinalis is a deep muscle of the back. It is the smallest of the muscle columns within the erector spinae complex, and can be divided into the three parts – thoracic, cervicis and capitis (although the cervicis part is absent in some individuals). Attachments: Arises from the lower thoracic and lumbar vertebrae, sacrum, posterior aspect of the iliac crest, and the sacroiliac and supraspinous ligament. It attaches to the spinous processes of C2, T1-T8 and the occipital bone of the skull. Actions: Acts unilaterally to laterally flex the vertebral column. Acts bilaterally to extend the vertebral column and Innervation: Posterior rami of the spinal nerves. Blood Supply: Muscular branches of vertebral artery, deep cervical artery, and posterior branch of posterior intercostal artery By TeachMeSeries Ltd (2026) Fig 1The erector spinae. 3D ModelPro Feature 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 Frequent questions What is the spinalis muscle? The spinalis muscle is a deep back muscle and the smallest component of the erector spinae group. It consists of three parts: thoracic, cervicis, and capitis, with the cervicis part occasionally absent in some individuals. Where does the spinalis muscle attach? The spinalis muscle originates from the lower thoracic and lumbar vertebrae, the sacrum, the posterior iliac crest, and several ligaments. It attaches to the spinous processes of C2, T1-T8, and the occipital bone of the skull. What actions does the spinalis muscle perform? The spinalis muscle laterally flexes the vertebral column when acting unilaterally and extends the vertebral column when acting bilaterally. These actions contribute to maintaining posture and facilitating movement of the spine. What is the innervation of the spinalis muscle? The spinalis muscle is innervated by the posterior rami of the spinal nerves. This innervation allows for the muscle's function in spinal movement and stability. What is the blood supply to the spinalis muscle? The spinalis muscle receives its blood supply from the muscular branches of the vertebral artery, the deep cervical artery, and the posterior branch of the posterior intercostal artery. This vascularisation is essential for muscle function and health. Rate This Article