One more thing that I would add is to be aware that this and many other myofascial release techniques often address only part of the issue. This is fine if the symptoms are from general wear and tear on the body due to regular use, but there is usually an underlying reason for the symptoms in the first place. A a common cause of upper trapezius soreness is poor posture. Many of us when not yoga-ing around sit in front of computers, in cars, and at desks in an forward rounded posture which puts the upper traps in a weak position to constantly hold your head up. It's like reaching your hand out as far as you can then constantly holding a 10 lb weight in it. This will strain the muscles and create tender points which can cause pain.