Dr. Andy Galpin

Does one have more range of motion than the other one?

Et cetera, et cetera.

So that's just one example of how we would look at the range of motion and symmetry within one joint.

The third thing we want to look at is stability.

Let's imagine that same squatting movement.

So I want to look at now, say, my knee.

I'm going to ask the same thing.

Can my knee go through a full range of motion?

Is it symmetrical?

So is the left knee doing the same thing that the right knee is doing?

And then thirdly now, is it stable?

So is the joint able to go up and down under control without excessive wobbling or shaking or any other movement pattern that I'm not intending to do?

To me, that's stability.

Really, you're talking now a combination of motor control and strength, but we can globally think of that as, is the joint stable when I'm asking it to be stable?

Human movement is really two things.

It is asking a joint or muscle or muscle groups to move in a way that we want, and also at the same time, not move in ways that we don't want.

Both of those are critical to moving well.

The third and final element here is simple awareness.

So is the individual aware of what their joint is doing?

A lot of times movement dysfunction like this is simply somebody not knowing their foot is not supposed to point in that direction.