I'm wondering about the commonly held idea that after you push off you should bring your heel up to your butt in order to shorten the length of the lever and thus bring your foot through the stride cycle more quickly.
My question is, should you do this by flicking your heel towards your butt as if you are doing butt-kicks (this is what many top distance runners seem to be doing) or should your heel come up to your butt as a result of driving your knee forward.
The first option seems to bring the foot through a circular type motion (similar to a cycling motion) while the later seems more piston like.
Perhaps the first idea is better for distance runners and the later is better for sprinters?
One last thing. The reason I'm asking this is because my heel doesn't naturally come towards my butt and I believe that my stride is being restricted in its range as a result. Thank you for any insight.