1. Multifidus Origin Posterior surface of sacrum, aponeurosis of erector spinae, posterior superior iliac spine, posterior sacroiliac ligaments, all lumbar mamillary processes, all thoracic transverse processes and the articular processes of the lower four vertebrae of cervical spine Insertion Spinous process of L5 - C2 Action - Extension of spine, head and neck
- Aids in control of trunk lateral flexion
- Rotate vertebrae within vertebral column
2. Semispinalis (thoracis/dorsi, cervicis, capitis) Origin Transverse processes of T1-T6 and the articular processes of C4-C7 Insertion Spinous processes of the upper four thoracic and lower two cervical vertebrae (thoracis/dorsi), cervical spinous processes (cervicis), between superior and inferior nuchal lines of the occipital bone (capitis) Action - Extension of spine, head and neck
- Aids in control of trunk lateral flexion
- Maintains posture of the head
3. Rotatores (Not pictured, resides along thoracic spine below multifidus) Origin transverse process of one vertebra (short and long rotatores) Insertion The spinous process of the vertebra directly above origin (short rotatores), and the base of the spinous process of the 2nd vertebra above origin (long rotatores) Action - Rotate vertebrae within vertebral column
- Extension of the vertebral column
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