Tack is a piece of equipment or accessory equipped on horses in the course of their use as domesticated animals. Saddles, stirrups, bridles, halters, reins, bits, harnesses, martingales, and breastplates are all forms of horse tack. Equipping a horse is often referred to as tacking up. A room to store such equipment, usually near or in a stable, is a tack room.
Saddles are seats for the rider, fastened to the horse's back by means of a girth (English-style riding), known as a cinch in the Western US, a wide strap that goes around the horse at a point about four inches behind the forelegs. Some western saddles will also have a second strap known as a flank or back cinch that fastens at the rear of the saddle and goes around the widest part of the horse's belly.
It is important that the saddle be comfortable for both the rider and the horse as an improperly fitting saddle may create pressure points on the horse's back muscle (Latissimus dorsi) and cause the horse pain and can lead to the horse, rider, or both getting injured.
There are many types of saddle, each specially designed for its given task. Saddles are usually divided into two major categories: "English saddles" and "Western saddles" according to the riding discipline they are used in. Other types of saddles, such as racing saddles, , sidesaddles and endurance saddles do not necessarily fit neatly in either category.
Stirrups are supports for the rider's feet that hang down on either side of the saddle. They provide greater stability for the rider but can have safety concerns due to the potential for a rider's feet to get stuck in them. If a rider is thrown from a horse but has a foot caught in the stirrup, they could be dragged if the horse runs away. To minimize this risk, a number of safety precautions are taken. First, most riders wear riding boots with a heel and a smooth sole. Next, some saddles, particularly English saddles, have safety bars that allow a stirrup leather to fall off the saddle if pulled backwards by a falling rider. Other precautions are done with stirrup design itself. Western saddles have wide stirrup treads that make it more difficult for the foot to become trapped. A number of saddle styles incorporate a tapedero, which is covering over the front of the stirrup that keeps the foot from sliding all the way through the stirrup. The English stirrup (or "iron") has several design variations which are either shaped to allow the rider's foot to slip out easily or are closed with a very heavy rubber band. The invention of stirrups was of great historic significance in mounted combat, giving the rider secure foot support while on horseback.