Responding to public outcry following the Internet posting of a video showing an international-level dressage competitor warming up a horse using a method some call inhumane, the Fédération Equestre Internationale (FEI) has launched an investigation.

The so-called "blue tongue video" shows Swedish Olympian Patrik Kittel riding the Grand Prix-level Dutch Warmblood stallion Scandic at the CDI Odense, Denmark, in October. The competition was an FEI-recognized competition and a 2009-2010 Western European League FEI World Cup Dressage Final qualifier. Video shot at the warm-up arena shows Kittel riding Scandic in apparent "hyperflexion," in which the horse's neck and poll are flexed longitudinally such that the nose is low and near the horse's chest. Dressage enthusiasts were particularly outraged to see Scandic's tongue lolling out one side of his mouth and with an apparent blue tinge, which some attributed to inhibited blood circulation caused by the method of riding and the strong bit pressure. In the video, Kittel halts the horse, leans forward, and adjusts the tongue before continuing on.

Kittel and Scandic placed third in the competition.

Hyperflexion (sometimes referred to as "rollkur") has been decried by some as contrary to established principles of correct, humane dressage training. Among the most outspoken critics is German veterinarian Dr. Gerd Heuschmann, who produced a book and a companion DVD entitled Tug of War: Classical Versus "Modern" Dressage. He writes that, in hyperflexion, "enormous tension is placed on the upper neck muscles and ligament system, and the back. While the horse's back does 'rise,' it is overstretched and tense, which restricts the hind limbs' ability to step under the trunk. The result is an uncomfortable, unhappy horse that is on the forehand with trailing hind legs, and unable to truly collect