ok heres my point and question...

if you walk normally (heels and toes) at a moderate pace and then keeping the exat same pace rise up on the balls of your feet and continue to walk you will notice a considerable drop in pace...

now, its obvious and common knowledge throughtout the athletics world that the larger surface area of a muscle or in this case foot, the more power can be produced...thi is very obvious with the first paragraph i wrote...

now my question is, why are we taught to run on the balls of our feet and not the entire foot like done in walking? why is this way supposed to be best for sprinting ?

THis answer will be much shorter than it should be but here goes... The reason we want to make contact on the ball of the foot while sprinting is to take advantage of the stretch-shortening cycle and elasticity, namely in the achilles/ gastroc-soleus complex. By striking on the ball of the foot this complex effectively stretches and then rapidly contracts (like a thick rubber band) creating greater force production in a shorter time, or more power. If we were to use the entire foot we would be trying to 'push' through the movement, which is much slower, allows for greater deceleration and transfers more force through the inelastic (bone) tissue rather than elastic (muscle & connective) tissue. For more on this topic I would refer you to Speed Dynamics Video series available on www.performbetter.com. Hope that helps.

The best place is toward the rear of the ball of the foot - not "up on the toes" with foot pointed downward before or at impact. People are best to have maximum dorsiflexion without impact heel first. Most athletes should have their heel kiss the ground - not miss contact - as this will guarantee they will waste energy striking slightly too early at impact and compensate for the shock of the impact by having to lean forward.