Phil, That's more than a theory--it is what is really happening. The foot being oriented outward does give the knee a twisting motion--in my case, it goes farther up and involves the hip which has lots of pins. On a bike, that motion does not happen unless your foot peg is way out and you have to twist in in order to use the brakes or shift lever. Besides, cages are boring unless you drive a Porsche Carerra--and then you lose your license. I'll take the bike.