How do you prevent splay leg?

From what I have read on this message board and other internet sites, spraddle leg must be treated in the first few days. Otherwise the hen will not be able to walk normally (if at all).

Here is a helpful website:
http://www.poultryhelp.com/spraddle.html

and scroll down to the bottom on this page:
http://www.feathersite.com/Poultry/BRKRaisingChicks.html

 

I only get spray leg when I take them out of the incubator too soon, I found the longer I leave them in, they better off they are!