How much does it take?
 

http://www.youtube.com/watch?v=CECto...=TL9ouxgD39M7E

My comment was:

MacDonald exercises take care of the left knee movement in the start up/backstroke. But it doesn't deal much with the downstroke. But that is where this movement in the video comes in - to reverse what has happened in the start up?

Looks like he wants the knee to return aligned with the feet in a natural position.

Airplane drill
 

Shock absorbers
 

Yoda has made it very clear through the years on this forum - the knee movements in a swing accommodate, and are a result of, proper hip action in the framework of the tripod. Focus on proper hip movements, not the knees.

Thanks
 

It's useful to be reminded of the important aspects.

Maxi