Hi, I had gone through your question and understand your concerns. By far the most common cause of a stiff neck is a muscle strain or soft tissue sprain. In particular, the levator scapulae muscle is susceptible to injury. Excessive stress or anxiety, which can lead to tension in the neck is also possible cause and holding the neck in an abnormal position for a long period, such as cradling a phone between the neck and shoulder. YOu should apply warm compresses, rst and take anti-inflammatory medicines, such as ibuprofen (e.g. Advil) or naproxen (e.g. Aleve). In some cases neck collar may be required but only if these remedies wont be helpful. Hope this answers your question. If you have additional questions or follow up questions then please do not hesitate in writing to us. I will be happy to answer your questions. Wishing you good health.