We all do.
The bones in our head have very subtle, normal, rhythmical, motions.
These motions are not synchronized with our heartbeat or breath. They are characteristic to the cranium, and are thought to be related to the circulation of the cerebrospinal fluid that bathes the brain and spinal cord.
Abnormalities in the rhythms can be associated with headaches or vertigo, or just feeling "out of sorts."
I find that balancing the cranial rhythms often relieves a patient’s headaches, and can be effective for vertigo as well.
Balancing patients' cranial rhythms is part of my focus on overall, full-body balancing.