Multifidi and Rotators A : Unilaterally – rotate the vertebral column to the opposite side Bilaterally – extend the vertebral column O : Multifidi – sacrum and TP of lumbar through cervical vertebra Rotator – TP of lumbar through cervical vertebra I : SP of lumbar vertebrae through second cervical vertebra N : dorsal primary divisions of spinal nerves Semispinalis capitis A : extend the vertebral column and head O : TP of thoracic vertebrae, articular processes of lower cervicals I : SP of upper thoracic and cervicals and superior nuchal line of occiput N : dorsal primary divisions of spinal nerves