I don't know about heel area, but if you massage my calf, inner leg, ankles it hurts as I have protruding veins. I don't have varicose veins, I just have very strong vessels that are visible.Nobody touches my nothing!
When I had an endoscopy, nurse nasty was about to put an IV. My vein is like 1/3 inch up as it is. She massaged out of the blue with the strength that could choke a cow! I literary gasped from the insane pain. She was all condescending, and my vein was bruised in a second and protruding like a pipe. It was so big it was scary like a horror show.