Odd ladder/slapper bar things. (what are they called?)

cant remember the technical name but slapper bars work too

when you get on it the torque from the tires and driveshaft makes the axle want to "twist" the leaf springs..

these stop the axle from twisting but still allows suspension travel

but ive seen them on a lot of cars and every camaro (seems like) soo they must work for something

ever juiced a 2wd pickup in gravel? thats wheel hop