Classic Skiing-Don't Pull From The Heel!

This discussion of the Kris Freeman Video got me to thinking about the
best info I've heard about Classic Skiing. For years begginning in the
1980's coaches were telling us to pull from the heel when loading the
ski during the kick phase. Their theory was this would elminate slip
and give a better purchase of the kick wax.

A few seasons back during a race on the Tug Hill Plateau I was skiing
behind Matt Belizi a former NCAA standout skier. He was getting
amazing drive forward and his tempo was less than mine. I could never
figure out his power until I read some remarks by Oddvar Bra last
winter. Remember him...he won more Classic Worlds Cups than any other
skier? The guy all the coaches use to tell us was perhaps the best
technician at classic. In his comments he said after classic skiing
the balls of your feet should hurt. He went on to say it is incorrect
to pull from the heel as coaches tell skiers. So I experimented and
surprise there was the power. Moreover, it reduces tightening in my
lower back! I can run the Friends Lake Inn ski trails for hours, but
everyone knows the lower back pain which can come from classic skiing
up hills. My theory is a runner comes of the ball of the foot as he
drives forward on hills not the heel. When pulling from the heel
during skiing there is a slight hang time, in which the lower back
muscles hold the leg high and back bringing on fatigue. I usually
don't jump into these technique discussions at RSN, but I thought
maybe this would help.