If someone is suffering from shoulder pain that doesn't mean the source of the pain is coming from your shoulder. One of the main culprits of Shoulder pain surprisingly is the neck. If you can move your shoulder around easily without any feeling of pain than your neck is probably the source of your shoulder pain. On some occasions the shoulder pain radiating from your neck can Make your shoulder stiff and painful to move.
Read more: Referred Pain around the Shoulder - HuffPost