Shoulder impingement and bursitis

I strained my neck in August of 2008 which resulted in a lot of pain. I took muscle relaxers/ibuprofen and after two weeks started physical therapy. It seemed to go well except for this trigger point in my upper trapezius muscle. PT was unable to get this knot to go away and referred me to a chiropractor thinking that something underlying was causing the persistent knot. After going to chiropractor, he suspected problem with rotator cuff since lifting my arm out and up were painful and after use of arm I would get a constant ache and burning on top and front of shoulder. Went to orthopedic doctor and got an MRI since he suspected a possible tear. The MRI showed just shoulder impingement and mild bursitis. So now back at physical therapy for my shoulder. While I know that with continued exercises, my shoulder will heal, I am concerned about this trigger point which I feel causes more pain than my shoulder since a lot of the ache happens right there and when it is pressed it is very painful. The PT uses ultrasound/TENS for it and also did this for my neck PT and it is still persisting. I have done everything I have been told to do as far as exercises and keeping my computer workspace ergonomically sound and I am constantly aware of my posture. I go back to orthopedic doctor in a couple of weeks. What else can get rid of this knot that makes me so uncomfortable every day?