Finally, I found ski boots and bought them. Of course I had to test my boots. I must agree that there is a huge difference between boots and boots. I didn't feel any pain in my legs (caused by the boots). A slight pain in my "tail" caused when I heroically saved one kid's life who happened to lie down on my way. Another fall down happened during the last slide. Nothing dramatic and I'm in one piece.
Downhill skiing seems to be fun and good physical exercise. I think the next investment will be my own skis.
( My downhill skiing boots... )