Running Mechanics

As promised just thought I would talk a little bit about running mechanics.

The take home message of this whole thing will be understanding the kinetic chain. Again when someone has a problem it is never in a vacuum one thing leads to another and another. This is the reason why in the weight room we don't use exercise machines. The body doesn't use muscles in isolation. We train movements. Use the exercise machines if your goal is to look good at the beach not if you want to actually use those muscles.

Anyways, the best place to start is with posture. It needs to be upright. Your body is only stable underneath your center of mass. When people lean forward their center of mass (CoM) also moves forward. To stabilize themselves they need to bring there foot down in front of them because the foot will land underneath the CoM. Try it. Lean forward while running and you will notice that your foot contacts will land in front of you. (This will also speed up your turnover, but decrease your stride length) The biggest offenders are distance runners. They for some reason are taught to land on their heel and roll over it. Well to land on your heel you need to lean forward. Again this is just an example of how everything is connected... your posture determines your foot placement.

So why is it important for your foot to land underneath you? Simply it lets you reuse energy, allowing you to conserve energy until the end, or run at a higher energy demand while not fatiguing as much.

Within muscles there is elastic tissue. When elastic tissue is deformed (stretched) it returns to its initial position. Well this characteristic can be used in running. Tendons are also elastic. When you bring down the foot forcefully on the ball of the foot, it causes the achilles tendon to be stretched out. So that force that you used to bring down the foot is 'stored' in the achilles tendon. When the tendon snaps back (it is elastic) it causes your ankle to extend, which causes you to push off the ground. The best part of this is that it is a reflex, meaning it happens naturally and quickly. Top runners spend less then one tenth of a second on the ground. This would be impossible with out reflexes. The longer you are on the ground the more you slow down.

So what happens when your foot hits in front of you. Well if you hit the ground hard, you will slow down. By creating a braking force. (Newtons 3rd Law) So people who lean forward need to have a 'soft' landing to prevent slowing down. However, with a soft landing the elastic tissues aren't loaded up. So you will have to produce the energy that brings your leg down and then you will have to provide the enrgy that pushes off the ground. No energy is being reused.

Also because if is not a reflex anymore people spend more time on the ground (causing a decrease in speed, so they need to push off longer which causes the leg to swing way behind the body) we call that back side mechanics. With that leg so far behind you, you don't have enough time to get it out in front again and you are stuck with another 'soft' landing.

I could keep going but I will stop there for now. I will post a little soap box rant about running shoes now though.