Which factor may cause abnormal motions in the cranial bones according to PRM?

• A. Trauma and physical stress
• B. Balanced membranous tension
• C. Inherent motility
• D. Fluctuation of CSF

Answer: (A)

Trauma and physical stress can disrupt the primary respiratory mechanism, leading to abnormal cranial bone motion. In cranial osteopathy, the primary respiratory mechanism describes subtle, inherent motion of the cranial bones governed by the meninges, CSF, and dural membranes. Normal components include inherent motility of the cranial bones, fluctuations of CSF, and balanced membranous tension that together sustain, rather than disrupt, motion. External forces like trauma can upset these delicate dynamics, creating restrictions or asymmetries in motion. The other factors—inherent motility, CSF fluctuation, and balanced membranous tension—are part of the normal mechanism and do not by themselves cause abnormal motion; they support healthy cranial movement unless disrupted by external stress.