The pillow is not a cervical spondylosis, it is a sprain of the neck muscles, often due to poor sleeping posture, the head and neck for a long time in an excessively deflected position; or because the pillow is not suitable for sleep, too high, too low or too hard, so that the head and neck in a state of over-extension or over-flexion, causing muscle tension on the side of the neck, sprain. A drop pillow is an acute strain injury to the soft tissues of the neck.