Lots of skaters could be much more effective in using heel-brake for
slowing and stopping, if they understood better how to make it work.
There's at least three different methods for braking with a heel-brake,
and for different configurations of skate - wheelframe - brake, some
methods work better than others.
Some websites about heel-braking
seemed (as of December 2005) to have confusions of moves and positions
for one method with those for another method.
I am not an instructor. I'm a skater who has tried
some different heel-brake designs and different heel-brake (and
non-heel-brake) stopping methods -- and who knows the relevant physics
pretty well, and has put some work into analyzing how the structure of
heel-brake design and skate + frame + brake configuration work to stop a
skater.
Skaters who want to learn something this important for
not getting hurt, should learn it from someone experienced with the
tremendous fascinating complexity of helping real humans succeed in trying
new actions -- an insightful and experienced human instructor (not just
from reading
some words on a web page based on physics).