Pain around the neck and upper back is simply is as a result of muscle imbalance caused by poor posture while sitting, standing or at work. The pain is an indication that something is not right in that region. Subjecting the body to the causes without exercising will increase the symptoms.
The symptoms include:
1) Sharp ache in the neck and upper back caused by forward head posture.
2) Tight chest muscles.
3) Drooping shoulders.
4) Head aches
5) Overall weakness

Here is a simple exercise to treat this.
Do the Prone Cobra Morning and evening before going to bed. Hold yourself up for a count of 10 seconds. Do 8-10 reps each day. This exercise tightens the back muscles and loosen the chest muscles. When your back muscles are stronger than your chest muscles, those symptoms will stop. See photo below...