You direct your energy/force against the thumb and keep moving so the force keeps directing against the thumb and that will break the grip.
Worth repeating!
Another trick: While lieing in bed, turn on your side. Practice swivelling around on your side kicking your legs as fast and hard as you can. Good if a perp surprises you while you're in bed.
146 posted on 06/08/2002 4:59:32 PM PDT by EverOnward