Have someone do AP glides on C5 in supine, this stands a good chance of reproducing neuralgia in the bicep, should the most common cause be present. Have him/her continue till the pain has gone to both C5 and the bicep. You will have an insight into the proposition that you have protective behaviour in your cervical spine with somatic referred pain as a result. This is by far the most likely and happily ,the easiest to fix.