The Atlas
The first cervical vertebrae (skull-C1 joint) is called the Atlas, after Atlas in Greek mythology. He holds the world on his shoulders. Like him, we hold the globe of the skull, our crown, on the atlas, C1.
The head and neck posture signal your mood to the world—you are communicating a feeling of poise, assertiveness, meditation or alternatively, dejection. Poor neck posture can contribute to headaches, even neck and eye strain.
One interesting way to look at the posture of the neck is to think of it as reflecting the curves of the spinal segments below it. The spine has an “S” shape that enables weight-bearing and movement. When you stand with these spinal curves in neutral, the neck will nicely stack over the body. Whether you slump or stand tall and aligned, the neck will be affected. How you choose to hold your lumbar (low) and thoracic (middle) spines will create health or havoc for the cervical spine above them.
Looking at this conversely, how you choose to hold your neck will create health or harm for the spine below it. Notice that with your head angled forward (think, staring at your cell phone) and not efficiently stacked over the lower vertebrae, you place strain and stretch on the upper back and draw the low back out of alignment. You also shift your center of gravity.
Kinesiology — How the Neck Moves
At the skull-C1 joint, only two movements are allowed—flexion (think chin down) and extension (chin up). Further, the apex of extension is at C4 and the apex of flexion is one segment lower, C5. This means that these are also the points of greatest wear and tear for the cervical spine (C4 for extending the neck and C5 for flexinging it).
Tuck your chin slightly
Standing with all spinal curves in neutral creates the conditions for the least amount of strain for the neck—the cervical spinal structures. How can you check this? The top of your ear should align slightly higher than the top of your eye. Can you draw this line in your mind? Often people carry their chin slightly higher—not healthy head posture.
Given that the cervical spine is composed of facet joints (not ball and socket joints), rolling the head and neck is also not a great idea. This is a non-anatomical movement—the body was not designed to move in this way.
Anatomy
The spine has 7 vertebrae. The first cervical joint is notable as it is the only movable vertebrae that has no vertebral body. Instead, the union of the distal skull and the C1 joint is shaped like cup and saucer, the skull being the cup and C1 being the saucer. There are no intervertebral discs between C1 and skull (or C1 and C2). Also unusual is that the neck houses a passage for one of two blood supplies to the brain (via the vertebral foramen, a passage for the vertebral artery). This means that the movement of the cervical spine can directly affect the blood supply to the brain.
Note how the low back and neck reflect one another –they are sympathetic curves. Try placing one hand on your low back (lumbar) and one on your neck (cervical spine) and round forward like you were typing. Note the (kyphotic) curvature in the neck is mirrored in a rounding (stretching) of the low back. The lumbar and cervical vertebrae are secondary curves and develop after birth.
Law of side-bending and rotation
Side bending and rotation occur to the same side, regardless of the position of the cervical spine at the beginning of movement (when you side bend right, the vertebrae rotate right). Exception: C1-C2 joint rotates the opposite way when the cervical spine side bends —this allows the face to stay forward.
Key Idea - Carrying your head over the body will contribute to overall health. Chin up, I mean slightly down, my love.
The head is heavy!
How posture affects weight distribution of the head:
