Thank you, Dr. D.
To answer your questions:
-- To explain the pain below my elbow, I took a closer "look" at it. As with the initial pain in my upper arm (near the shoulder), the pain there is difficult to pinpoint. But if I palpate the area, the pain is actually right AT the elbow, not below it. I feel it ONLY while moving my arm, but not always. I was assuming that it could be the result of the now-increasing fatigue in my upper arm and perhaps some other muscles having to compensate.
-- Neck movement does NOT bring about ANY of the pain I've described anywhere in my shoulder or arm.
-- If the cause of my RC cuff is anatomical, and is bi-lateral, then it stands to reason that my dominant arm would feel the pain first, followed by the non-dominant arm.
-- The exercises are to improve scapular strength/function, and include (always while keeping shoulder blades pinched): (1) Holding a short resistance band with both hands, elbows at 90 degrees and at my sides, gently pulling band from each end; (2) with one hand at my side and bent 90 degrees, pulling the handle attached to a resistance rope(?) until there is only gentle resistance, holding for 20 seconds, repeat several times, then repeat in other direction (gentle internal rotation / abduction, but always keeping my hand straight out in front with elbow bent 90 degrees; (3) full planks for 15 seconds; (4) gentle circles with arms at my sides; (5) small movements to wiggle a body blade. ***ALL OF THESE EXERCISES ARE DONE WITHIN MY LIMITED PAIN-FREE RANGE OF MOTION AND ONLY IF I AM PAIN-FREE WHILE DOING THEM *** However, even when these exercises don't cause pain while doing them, my shoulder hurts more the next day (by "hurt", I mean more intense sharp/tearing pain).
-- I have used ice after the exercises, but not always. The PT center sometimes offers ice after the exercises, but it's not always offered (however, it's always given if I do ask). About a month after this began, I iced the shoulder several times/day, but I did not feel any relief or improvement so I have not continued as often. Besides, I've read conflicting things about inflammation ---- some say it promotes healing, and others say it doesn't!
-- When I raise my arm close to 90 degrees or above, I feel intense/sharp/tearing pain about 4 inches from the top of my shoulder as well as the front of the joint (around the glenohumoral joint). If I raise it even once with some pain, the next attempt is even more painful and more limited. (i.e. each successive movement makes the next one even more painful and limited.) External rotation beyond about 20-40 degrees is very painful (again, each successive attempt is more painful and limited than the previous one).
-- Oh, one more thing.... if I pinch the shoulder blade (apply excellent posture) while raising my arm, I can raise it higher with less pain. The doctor and PT encouraged me to do this to put less strain on the RC.