Running Shoe design

This idea for running shoes is a bit complex but if it would work it would be neat.

Make shoes that use hydraulics and valves to store up energy when the shoe hits the ground and then release it when the shoe is leaving the ground.

First the shoe would have to have an extension on the bottom (assume about 6") that is hydraulically controlled. It would add 6" of height like a platform shoe and the extra 6" could be reduced to 1" by the hydraulics.

When running and a foot hits the ground, the hydraulic fluid is compressed in a small tank in the shoe, which reduces stresses on the body and stores the energy. When it is compressed as much as it will be (maybe a chip to help figure this out), a value closes off the tank so that there isn't much upward force. Then when the runner starts to push off with that foot (I assume the chip could figure this out), the value is opened which releases the energy giving a very useful extra push.

It would also be nice if the chip would flatten the shoe when it was lifted into the air so that the runner wouldn't have to lift his foot much to bring it forward. From talking to runners, short strides are better than long strides because long strides require lifting the foot higher which uses different muscles that get tired sooner. This would reduce that problem and might allow longer strides with less foot raising.