## Ground reaction forces and gait

In part , my interest in biomechanics comes from understanding the TMJ but also from my hobby ,throwing things in track and field ( not very far ) .

Recently, I developed the idea that ground reaction forces in the stance leg can help produce vertical acceleration of the pelvis during gait which will in turn will accelerate the swing leg provided it has started on a downward arc . I feel that this might be an important part of gait and also and important part generating leg speed when it comes to kicking things like a football .

My question is ,is this at all a novel idea and might it be correct ?

The following analogy might help explain the idea - It is taken from the early part of a thread on Podiatry Arena .

Quote -
"As we walk our pelvises move up and down in the vertical plane (among others ) .
So take a pencil to represent the pelvis , and our string with a weight on it to represent the swing leg . Tie the string to one end of the pencil and hold the other end of the pencil in your hand .

So now you have a pencil held out from your hand parallel to the ground and from this dangles the string . Now lift your hand vertically up and down to represent a straightening , lifting stance leg . The string and weight will simply mimic this up and down movement .
However , if you first start the weight and string moving to and fro , as in a pendulum , then when you lift and drop the held end of the pencil , energy will be imparted into the swinging weight . If you've got rhythm that is !

And so yes , " Vertical forces produce horizontal progression during gait . " Not "impossible" since accelerating the swing leg will cause it to advance , in part , horizontally ."

Gerrard Farrell

Glasgow