How can a person squat to impact heavy weight?

How to use the squat rack?  

What can the squat stand do besides protecting the squat?

Please see the latest fitness video ->

http://v.youku.com/v_show/id_XNzQ4NzAxNDI4.html (Click the previous link string to view directly)

Viewing YouTube overseas: https://www.youtube.com/watch?v=J5Fa5tcrAKo&list=UUWSxF1o2ReVFot4Dc1VY3sg