How tight is your pedal?
How do you play: Heel Up or Heel Down?
I had leg problems that were brought on from driving me feet into the floor (Hey man, I was snapping PEDALBOARDS in half. I snapped 2 Pearls, and 2 DW's, and I sheared a Danmar Redball Mallet's "no bend" Mallet shaft in half!
All in the name of Volume.
See a doctor to make sure you haven't done any serious damage, and then do this.
Tighten your Springs as tight as they will go.
Play Heel Down.
Yep, it's a pain in the butt to learn, but you know what? I'm one of the fastest drummers around in my region, and one reason for that, was that I learned to play heel down, and then heel-toe.
The Heel Down technique will build the front side of your leg muscles, and even if you revert to playing heel-Up, you'll be a heck of a lot faster than you were prior to doing what I've posted above.
Once you are happy with your foot speed, then you will be able to lower the spring tension if you wish....it's just like lifting weights, the more tension (weight) you put on the pedal's springs, the stronger your foot and leg will be.
Tim
Tim