If you look at the blocks, you’ll notice that the pads are very long. When u start the heel needs to go back in order to go forward, this is called a stretch reflex.
Stretch reflex
“Another example is the group of fibers in the calf muscle, which synapse with motor neurons supplying muscle fibers in the same muscle. A sudden stretch, such as tapping the Achilles’ tendon, causes a reflex contraction in the muscle as the spindles sense the stretch and send an action potential to the motor neurons which then cause the muscle to contract; this particular reflex causes a contraction in the soleus-gastrocnemius group of muscles.”
maybe this is why they place the foot high up on the block so as the heel can go back with out hitting the pad.
although i think i saw john smith on HSI video teaching to put the heel against the pad when in the set postion.
Charlie,pj, any views on how does a high v low foot placement on the pad make a differnce to your acc mechanics from the blocks