Heels hitting the cranks - solutions?

[ny biker]

Work on strengthening your hip rotators, and on foot strength and flexibility so you're weighting four corners equally inside your shoes? Have you worked with a PT since your surgery?

I don't understand what weighting four corners means.

I worked a with a PT for many months after the surgery. I worked with another PT when the knee pain first surfaced, which was probably 5-7 years ago, I don't remember exactly. The knee rarely hurt after that, until recently when I tried to keep my heel from hitting the crank by changing the angle of my foot relative to the pedal.