It looks to me like your seat is a tad bit too high. Your leg should be straight when seated with your heel on the pedal. When pedaling with the ball of your foot on the pedal, you'll have a slight bend in the leg. Do you find yourself rocking left/right when you pedal? If so, the seat is too high. I would say somewhere around 0.5cm lower might help. Also the seat might be tilted down a bit? I've been told the seat should be flat; yours looks like it might be angled down a touch? I don't really have a good feel for proper front/back seat positioning. My two road bikes have slightly different seat heights and I can definitely tell the difference, but I'm not sure which I prefer. Perhaps some googling on how to do self-fit might help you tweak your bike to be more agreeable with your body.