Craniosacral therapy (CST) involves light holding of the skull and sacrum and barely detectable movements. Indeed, the action of craniosacral therapy is so gentle and slight that it is the best example of the so-called “subtle” therapies, which claim to achieve profound health benefits with minor and safe interventions. Practitioners believe that the tiny manipulations of CST affect the pressure and circulation of cerebrospinal fluid, the fluid that surrounds and cushions the brain and spinal cord. Practitioners believe that this manipulation regulates the flow of cerebrospinal fluid and aids in "primary respiration". John Upledger devised CST. Comparing it to cranial osteopathy he wrote: "Dr. Sutherland's discovery regarding the flexibility of skull sutures led to the early research behind CranioSacral Therapy – and both approaches affect the cranium, sacrum and coccyx – the similarities end there." However, modern day cranial osteopaths largely consider the two practices to be the same, but that cranial osteopathy has "been taught to non-osteopaths under the name CranialSacro therapy."