Achy Legs
     

What did he say?

Some of the terms used might not be familiar to you. I'll explain them to you.
You can pause the movie at any point and then start again.
     
What?   Explanation in English
     
posterior crural region   Back of the leg and muscles underneath
     
Pronation   Flat Foot caused by ankle bending inwards.
     
Neutral Position   Taking the bend out of the ankle. This is what an orthotic does naturally and it feels good.