Original sentence: Draw reins and running reins are pieces of riding equipment used for training that cause the horse to bring its head down and inward.Running reins and draw reins should only been used when the horse is performing an undesired behavior that cannot be corrected with less extreme equipment, and it is best practice to stop use as soon as the desired response is given.While a rein is the strap that connects to the bit and is held by the rider, these types of reins add additional leverage to the rider's hands and arms, allowing the rider to force the horse's head into a desired position
Edited sentence: Draw reins and running reins are pieces of riding equipment used for training that use the  Mechanical advantage of a 'single movable pulley' to cause the horse to bring its head down and inward.Running reins and draw reins are intended for use#REDIRECT Target page name when the horse is performing an undesired behavior that cannot be corrected with less extreme equipment, and it is best practice to stop use as soon as the desired response is given.While a regular rein is the strap that attaches to the bit and is held by the rider, these types of reins slide through the bit ring, adding additional leverage to the rider's hands and arms, allowing the rider to force the horse's head into a desired position