Longeing piece of twine or rope, though for a very skittish young horse they also can be thrown up over the top of the saddle and tied down in that fashion. A surcingle or roller is a padded band that straps around the horse's girth area, and has rings around on its side for side reins, or long reins or other training equipment, such as an overcheck. It may also be used on a young horse to get it used to girth pressure. It may be used with or without an English saddle underneath. Side reins are usually used for more
Girth (geometry) width, with the same width "w". All curves of constant width have the same perimeter, the same value "w" as the circumference of a circle with that width (this is Barbier's theorem). Therefore, every surface of constant width is also a surface of constant girth: its girth in all directions is the same number "w". Hermann Minkowski proved, conversely, that every convex surface of constant girth is also a surface of constant width. For a prism or cylinder, its projection in the direction parallel to its axis is the same as its cross section, so in these cases the girth