What is Clinton Anderson's method for fixing a horse that won't move forward from the leg?

A horse that won't move forward from the leg — that requires escalating leg pressure, constant kicking, or a crop every stride to maintain impulsion — is one of the most common and most correctable problems in riding, and Clinton Anderson's approach targets the root cause directly rather than addressing the symptom. Anderson's diagnosis is consistent: horses that are dull to the leg were made that way by their riders. Every time a rider applied leg pressure and the horse ignored it, and the rider either increased the pressure gradually or gave up and kicked harder, the horse was being taught that leg pressure is background noise that can be ignored until something more serious happens. The process of creating a leg-responsive horse requires undoing this learned dullness. His correction method begins on the ground. He uses the Driving Game to establish a crisp response to rhythmic pressure on the hindquarters — the horse should move forward immediately from one tap of the stick, without escalating pressure. Once this response is reliable on the ground, it is transferred to the saddle. Under saddle, Anderson uses what he calls 'the bump and spank' technique: apply the leg aid lightly, then immediately apply a firm reinforcement — either from a crop or from spanking the horse behind the leg — if the horse does not respond to the light aid. The reinforcement should be a single, clear stimulus, not repeated bumping. The moment the horse moves forward, the leg releases completely. This teaches the horse that the light leg aid is the warning and the reinforcement is the consequence, and that moving from the light aid avoids the reinforcement. Anderson stresses consistency: for the correction to work, every light leg aid must be followed by reinforcement if the horse does not respond within one or two seconds. A single exception — applying leg repeatedly without reinforcement — undoes several correct repetitions. The horse's response becomes as consistent as the handler's application.