We do this in Tai Chi
I teach Yang Family Tai Chi Chuan (www.yangfamilytaichichuan.com) in Crete, Greece.
One of the first things they taught me and I have been teaching my students is how to keep their knees over their toes, as well as the allowed range of movement of the knee with respect to the stance you are holding.
I have a few friends that have been training in Tai Chi with me, who had such problems with their knees, and eventhough Tai Chi puts stress on the knees, it also teaches you the way to move and strengthens them considerably.
I am just saying this to point out that we often revisit knowledge from the past (even from China).
