What really happens when we walk?

How we normally walk.

We use our feet as springs by pushing them down to push them off the ground. When we walk we feel the ground pushing back on our feet. This is the feedback we look for and rely on when we take steps consciously. It’s the feedback of  the ground pushing back on our feet that provides the spring in our step.

When we walk we don't actually lift our feet up instead we push them off the ground so it does not really help to tell someone who has freezing to lift their feet higher when they walk unless they change the way they think about walking. The first instinct is to push our feet down so that we can take a step. This is where the problem starts.

What causes freezing and shuffling?

When freezing of gait happens, PWP often say that it feels like their feet are glued to the ground. This is a good description of fog. It is the pushing down on the foot that is affected most by Parkinson's Disease. I  cannot feel my feet. So when I want to walk, my mind is unconsciously telling  my feet to push down on the ground to take a step. Experientially I am just taking a step, but what really is happening, I am pushing my feet down on the ground but it is so weak that it is not enough to push off the ground. So the feet feels like they are glued to the ground. 

Similarly, shuffling occurs  when the ability to push off has been significantly reduced and is not enough to clear the ground. So the steps we take are shorter because we aren’t able to push the feet off higher from the ground.

This ability to push the feet off the ground is also interrupted when some stimulus is present like a doorway appears, or interruptions or when a pwp has to multitask.    

This is key to understanding why  freezing occurs and why the solution works.