"A low neck position acts on the withers lever to raise the back. The spinal processes in the withers are drawn forwards and raised by the pull of the nuchal ligament, thus tensing the supria spinous ligament. A grazing horse bears its trunk weight without strain thanks to the upper suspension. This natural physical principle is a prime significance when training horses. The horse has to drop its neck and stretch out of the wither – and only if it does that, can the back muscles take on a positive tension – and that is the only way the horse can carry the rider in balance and free up the locomotion muscles to do their work creating impulsion."