What causes a crick in the neck, that feels like a nerve or muscle?

Trapezius muscle: The trapezius (connects the neck and mid back to the shoulder blade) is the most common muscle to develop 'trigger points'. Usually associated with poor sleep, stress, poor posture or long periods of sitting, insufficient stretching/exercise. A 'pinched nerve' root will cause pain down the arm and is not a typical cause of neck or shoulder blade pain.