CraigB

I may not be seeing the same things others are. The picture looks to me like you're rotating your foot out, not in (that is, your heel is closer to the bike than your toes). And pedaling with your toes is definitely going to overwork calves and other stabilizing muscles in your lower leg that should't normally get stressed much during riding. I wouldn't say to move your foot as far as Sixty Fiver is suggesting (I've always had the best success with the ball directly over the pedal axle), but you really do need to get the pedal more underfoot and not under your toes.

Your pic also points up one of the problems I've always found with riding in running-type shoes: they tend to have wide-platform soles under the heel and ball of the foot for running stability, and that extra width tends to catch on crankarms. In fact, if I had to guess from looking at the photo, you're already a little conscious of this extra width and might be trying to compensate for it a little. Look at your left foot and see where a centerline dropped vertically from the middle of the foot falls relative to the pedal. It's right in line with the outside edge of the pedal. I'm thinking that you're feeling a little insecure on the pedal because of that, and you're unconsciously rotating your right heel in toward the bike to try to regain a little sense of security - so it feels less like you're about to fall off the edge of the pedal.

That's just my guess. I could be all wet.