suren

I don't have enough knowledge on this, but as a beginning doing it on a very soft mat seems to be a good advice. It will help you to concentrate on your technique rather that being disturbed by the thought how to avoid the pain. That slow transition helped me a lot during forward roll. I could not touch my shoulder and developed a fear of rolling. By doing it for some time on a really soft mat (sensei calls it "granny mat"), then moving to a harder one I overcome the fear and developed the feeling of the technique. Hope the same works with highfalls.