It is hard to explain, kinda like if you run your fingers up the keys of a piano quickly, just feels like all the vertebrae are released simultaneously. My doctor didn't use a towel, he would get a good hold of my neck, position it right and give a good yard to it. He would also use his body weight to help get my hips in the right place. Lots of other ones I have seen only use their hands, some use the actuator, the thing that clicks and feels like a small hammer, or the electronic stimulus machine. That would work for my lower back only.