By Keith Bateman
Some people have been told that they should constantly fall forwards when running and that gravity provides a proportion of the forwards motion when running. This idea runs against the physical laws of motion.
When you land, you are leaning back to some degree (foot pressing on the ground in front) and when you take off you are leaning forwards (foot pressing on the ground behind you). Gravity pulls you down, not forwards—in running with good form, there is minimal braking and you go forwards mostly because you are already going forwards, rather like freewheeling on a bicycle—and your speed is reduced by braking and increased by pushing.
Assuming that you start and finish your run standing, the total of your forwards ‘falling’ must equal the total amount of your backwards-leaning braking.
This means that, at constant speed, the more forwards your take-off, the more you are leaning back, braking when you land. If you try to constantly tilt your body forwards and you are not accelerating, falling over, or running into a strong wind then you must be either:
- kicking your feet up behind you using them to balance
- advancing your leg under your torso (walking forwards)
Neither of these actions represent good running. They are both forms of walking along the ground which leads to poor times and injury.
Thought experiment on this idea
One of my clients came up with this to explain why this idea is flawed.
“If gravity could somehow propel you forwards while you were running that would mean that if you put a tower on a wheeled trolley and tipped the tower over so that it was falling forward then would it propel itself forwards on those wheels. I think the answer to that is clearly no. So why would gravity propel you forwards if you were a person falling over?”
Thanks to Steve Walsh for that thought.