The patient states that he has had this pain for many years. He describes the pain as “it crept up over time” and now it is keeping him from being able to work or play golf. Pain sometimes keeps him up at night. It worsens when he does any activity where he has to raise his arms or flex his neck for more than 10 minutes. This patient states that he was in an auto accident when he was a young child but received no treatment. He does not remember being in pain when he was young. He has no current disease or illness. This patient is not on any medication. He does not smoke. This patient was lifting weights but had to stop the pain. He was playing golf but carrying his own golf bags hurt his back. This patient has sought relief from massage, but it has not resolved his problem. He further describes that as a youth, he was a caddy carrying heavy golf bags mostly over his right shoulder.

Question: Based on this clinical history, what are some of the differential diagnoses you are considering?