Rollkur or hyperflexion of the horse's neck is a practice in equestrianism defined as "flexion of the horse's neck achieved through aggressive force" and is banned by the world governing body, the International Federation for Equestrian Sports (FEI). The FEI recognises a distinction between rollkur and the riding of the horse in a deep outline not achieved by force.
The technique has been controversial for some time in equestrian circles, including the set up of specific petitions and boycotts (including a threatened boycott of the London 2012 Olympics) to promote banning of the practice. Despite the controversy, the technique has been used by dressage and show jumping riders. The FEI moved to ban the practice following the release of video of Swedish dressage rider Patrik Kittel using rollkur during warm up at a competition in Denmark where the horse's tongue appeared to turn blue as a result of the manoeuvre.
Most usage of the technique in recent times has been by dressage riders but rollkur was, and is still, used in other equestrian disciplines, most notably show jumping, before being adopted by some well-known dressage riders. However, it is not an old theory in dressage, either: Francois Baucher trained a similar method, although he did all his severe flexing at the halt, and in addition he connected the posture of the hind legs to the mix.
In dressage training, the rider can choose to make the horse work for periods with its neck lowered and its head behind the vertical, for various beneficial reasons, such as suppling, relaxing, and stretching the horse, yet rollkur takes this flexion to the extreme. In rollkur, the horse is asked to lower his head and round its neck as it works—working "deep"--so that the head is coming inward. In the extreme, the horse's mouth touches the middle of his chest. Rollkur is not a quick movement lasting a few seconds, but is held for a length of time, through work at the walk, trot, and canter, including shortening and extension of the gaits. Rollkur is not just longitudinal flexion (nose to chest or forelegs), but accompanied with repeated bending to the rider's leg.
Some riders who use rollkur accomplish the head position by lowering and fixing the hands until the horse yields its jaw backwards in response to the pressure on the bit. This technique (pulling in) goes against all classical riding. In classical dressage, the horse accepts the bit and the horse decides to come down with its head because it trusts the hands of the rider. In good companionship, it is possible to ask the horse to go a little deeper than the animal would do itself, but to obtain the extreme posture of rollkur does require physical coercion.