A 19-year-old young man was diving and hit his head on the bottom of the pool. He complains of pain in the neck, his head movements are limited and painful. During, examination his head is bowed forward and to the right and the patient supports it with his hands. Palpation detects tense neck muscles and protruding spinous process of the IV cervical vertebra (C4). When pressure is applied to this process and to the head (axial load), the pain intensifies. Make the provisional diagnosis: