For yourcalf muscle, the opposite is thetibialis anterior, on the front of your shin.

Activate this muscle by using it to pull your toes upward, off the floor.

Sometimes the cramp will release instantly; sometimes I find it takes a good 30 seconds.

Whatever you do, though, don’t stretch!

In our calf cramp example, you’ll sometimes see people grab their toes and pull.

But that doesn’t help, and can even cause damage to the cramping muscle.

The point is to use the shin muscle to do that movement.

It’s essentially a signal for that opposite muscle to relax.

If the cramp is in your quad, activate your hamstrings (bend your knee).

If the bottom of your foot is cramping, lift your foot and spread out your toes.

Reciprocal inhibition to relieve muscle cramps| Tribook.org