see also: Offset
Timing | Balance+Commitment | Uphill
These diagrams show how different angles of the pole and
positions of the pole tip in the snow determine the "reactive"
forces that either push the skier forward or lift the skier's body
The blue arrow shows the force of
the skier's push on the pole, down and back against the snow.
But Newton's Third Law from physics says that every force has an
opposite reactive force -- and this "reactive" force can be
analyzed according to two components:
green arrow for the
forward-push on the skier
red arrow for the upward force
on the skier
The longer the arrow, the stronger magnitude of that force
The action force on the pole is down and back, so the components of
the "reactive" force are up and forward. Forward is
always good in classic stride, but upward can be good or bad -- good
during the glide phase, bad during the kick phase.
Physics says that the two components have to "add" together
in the "geometry" of the diagram. And you can see how
the red and the green start from the "arrow target" of the
blue arrow, and "bring it back" to the "arrow
source" of the blue.