Neck shoulder pain headache shoulder pain from a injury neck feel like it posing and cause headaches . why?

Gravity: Shoulder, neck, ; headache pains are causally related in 40's female post-cervical injury. Head weighs about ten pounds ; injured ; strained neck muscles become spastic to prevent painful cervical tilt; a cervical self-preservative splinting process. The trick is to resolve muscle spasm to prevent muscle deconditioning and weakness from disuse. Few weeks of disuse can further weaken muscles.