Back therapy = SM stomping on my back

A few days a ago the tips of my shoulders started to get really sore, and now its gotten to the point where my whole back is in some pain, with the most knots being in the upper left hand side of my back. I feel like a cripple and I have no idea why. In an attempt to try and take out my knots - Shirley did some back therapy for me. i.e. she stepped on my back trying to take out the knots. It helped a bit - but my left side hurts so much that I swore in pain by her just slightly stepping on it (the same pressure on my right side didn't hurt at all). I'd say we did a good 5-10 minutes with me screaming in pain...from fist stomping, light stepping and hand massaging...it sounds dumb...but it really did hurt! I think it helped abit...??