Stirrups

A stirrup is a leather strap ending in either a conical shielded foot rest or an iron ring. A stirrup is attached on each side of the saddle by a hook and several ties.
The stirrup has many uses. Its primary function is to expedite the mounting of the beast. The stirrup also helps the rider control the mount and stay on if struck by a forceful blow; stirrups are essential in a jousting match.
Stirrups steady the mounted warrior, allowing greater force to be put behind blows with less chance of falling off the mount. They allow mounted warriors with lances to charge effectively with a leveled lance, a feat nearly impossible without them.
Mounted fighters without stirrups who are struck in combat must make a save vs. paralyzation or fall from the horse.