A "flank strap" (or, "bucking strap") is used to encourage the horse to kick out straighter and higher when it bucks. The flank strap is about 4 inches wide, covered in sheepskin or neoprene and fastens behind the widest part of the abdomen.

Are bucking straps cruel?

When the flank strap is paired with spurring, it causes the animals to buck even more violently, often resulting in serious injuries. Former animal control officers have found burrs and other irritants placed under the flank strap.

What is a bucking strap on a saddle?

A flank strap is a sheepskin-lined or padded leather strap. ... On a new bucking horse, the strap around its flank causes a tickle, or at most an irritation (but so does any new piece of equipment on a new horse – even a saddle).