Quote Originally Posted by KSH
I say go with SpeedPlay. These pedals allow for you to move your foot some on the pedal... and thus will eliminate the problems that arise from having your foot locked in the pedal, in the wrong position. This is a possiblity if you have clipless pedals that do not allow any foot movement.

BUT... this is what worked for me and eliminating the knee problems I acquired riding my bike.

I agree with KSH as well! I'm still recovering from a knee injury, and just purchased a pair of Speedplay Zeros. They offer the most float (adjustable from 0-15 degrees), in addition to adjusting the spring tension. They have a large platform which makes long rides a heckuva lot more comfortable. I've used Look & Shimano before, but found the Speedplays more to my liking over the long haul. I'm using the Sidi Genius 5 women's shoes (road), which fit me perfectly.