I've had some problems with my knees and they now make lots of clicking and popping sounds when they move (its painless though) and so I don't quite trust my knees going as far over my toes as they need to in hindu squats. Can anyone think of some alternatives to them? How would monkey jumps compare or jumping squats?

http://www.ehow.com/video_2355134_ku...key-jumps.html

normall I do monkey jumps like this but kick my ass with my heels when im in the air.