Why does your ankle position on the peddle matter?
I live and love biomechanics as a physical therapist. I use it to work smarter not harder during some mean manual therapy techniques, I use it to decrease pain in your body, and I use it to make you faster.
The key here is to understand the athrokinematics or roll and slide in the joint of the ankle. The ankle is made up of 26 bones, many joints, and probably is one of the most complex regions of our body. The primary ankle joint used during cycling is the talocural joint or otherwise call the saddle joint. It's called a saddle joint because of how it's shaped. The talus sits on top of the heel bone and is wider in the front than the back. The shin bone is the tibia and the lateral bone is the fibula making a saddle shape to sit over the talus. When the ankle flexes up or dosiflexes, the tibia and fibula slides up on to the wide aspect of the talus locking the ankle so the power of your legs generate direct force into the peddles. You need to stiff rigid lever arm to get all the power to transfer into wheel torque=speed.
So when you are training and working to improve your overall skill at cycling, these details are where the hold lives. Hope this makes you all a little faster...
Dustin Hancock, PT, DPT Doctor of Physical Therapy