CV Intro

• the main purpose of the CV region is to make head movements independent from the rest of the vertebral column
• the craniocervical spine can express its mobility independently of the lower cervical spine
• the craniocervical spine is able to orient the head in three spatial planes, free from all influence from the lower cervical spine
• two main functions of OA joint:

  • transmit forces from head to cervical spine
  • provide a significant degree of mobility in the sagittal plane
• the occipital condyles glide posteriorly over the lateral masses of the atlas during CV flexion + anteriorly during CV extension
• side bending of the occiput in relation to the atlas is associated with a rotational movement toward the opposite side
• side bending of the occiput on C1 causes a pronounced rotation of C2 towards the side of the side bending
• rotation of the occiput is accompanied by extension + contralateral inclination
• the occipital condyle on the side of the rotation glides in the lateral + posterior direction

  the occipital condyle on the contralateral side of the rotation glides in the anterior + medial direction
• with rotation to the left, the tension on the right alar ligament increases + causes the right occipital condyle to glide to the left
• the translational component of the occipital bone during rotation is always ipsilateral
• supine nodding test:

  • normal: mid-point of chin should remain in the mid-sagittal plane
  • positive: chin deviates causing occiput to rotate towards that side