Pedal technique

Hi Alan First, many thanks for your excellent books which together with Feldenkrais lessons have helped me overcome severe epicondylitis as well as improve my playing. I am encountering pain in my right knee when pedalling so I am reviewing my pedal technique. In both your books you say that Horowitz pedalled by rotating his foot, keeping the outside edge on the floor. However I have just watched several videos of him on Youtube and I cannot see this. He seems to be pedalling front on just like most other pianists. When I try the method you describe, rotating from the hip and keeping my foot relatively quiet, I am more comfortable, but seem to have very little control and cannot quickly change pedal. I would really appreciate more detail on what you consider the optimal movement when pedalling, in foot, ankle, knee and hip. What angle does your foot bear to the pedal? Does your foot flex or just the knee? Are your lower legs perpendicular to the ground as you play? Which part(s) of your foot are on the pedal? Any thoughts gratefully received. Thanks Alan