Cerebrospinal Fluid and the Craniosacral Rhythm Perhaps the most basic principle of Osteopathy is that the body should freely move in response to the Craniosacral Rhythm. This rhythm is produced by the production and reabsorption of Cerebrospinal Fluid (CSF), which is found circulating the brain and spinal cord. It can be found in the ventricles of the brain, the central canal of the Spinal cord, and the Subarachnoid space. The production and reabsorption of CSF is what we