Prone Shoudler arcs can help strengthen upper back muscles which hold your shoulders in better posture.
By lifintg a dowl or light pole up off the floor and moving the shoulder can help strengthen the muscles between the spine and shoulder blade
Shoulders and shoulder blades which are relaxed and sit back and down instead of hunched up and slouched forward are better for your posture. Good posture can prevent neck pain, shoulder pain and headaches in the future.
For further hints and tips on postural care and general healthy living go to http://ccbrighton.co.uk/videos-exercises-back-pain-neck-pain-sports-injuries/