There'* a difference between a "pull" and a "cramp". Those ones you get in your calves when you're stretching while lying down are cramps. Truly **&$ks. Makes your toes spread apart. Gotta jump out of bed a walk around to ease the pressure. Extra Potassium in the diet will help prevent these.
As far as groin pulls, anyone who has ever played sports should be familiar with that pain. And the general discomfort associated with such a pull while it heals.
WORST pull of all... abdoman