A 60 year old woman presents with acute onset of bone and back pain following a rough journey in a car. Examination: tenderness at mid-thoracic vertebra with spasm, she feels better once she bends forward. What is the single most probable diagnosis?

The key is B. Myofacial pain. [Myofascial pain syndrome is a chronic pain disorder. In myofascial pain syndrome, pressure on sensitive points in your muscles (trigger points) causes pain in seemingly unrelated parts of your body. This is called referred pain. Myofascial pain syndrome typically occurs after a muscle has been contracted repetitively].