I've always had a problem with this.
I have flat feet, meaning, no curve in my foot. My vertical leap is not affected, it is 25 inches. I think that's pretty good.
The thing is, when I do aerodynamic exercises(which I have to do often, because of my martial arts training) my ankles SOMETIMES start to hurt.
Generally they are weak.
When I do jump squats, they hurt afterwards for a bit. Or lift heavy weight, I can hear them crack.
My question is, to how I can strengthen my ankles?