The hyperflexion position of a horse’s neck (commonly called "rollkur") might be causing more stress to the humans arguing about it than to the horses actually performing it–at least while being longed, according to one Austrian equitation scientist.

This highly controversial neck position caused no physiological signs of stress in 16 study horses longed at all three gaits with moderate hyperflexion, compared to the same horses longed with a normal neck position, said Christine Aurich, DVM, PhD, professor at the Graf Lehndorff Institute at the University of Veterinary Sciences in Vienna. Aurich evaluated immediately after being longed heart rate, heart rate variability, and salivary concentration of cortisol–all commonly accepted stress-measuring parameters–and found no significant differences between horses working in hyperflexion and those that did not.

During a presentation at the at the 2011 International Equitation Science Conference, held Oct. 26-29 in Hooge Mierde, The Netherlands, Aurich said the only difference she detected in the two neck positions while the horse worked on a longe line was a larger variation between minimum and maximum temperatures of the neck skin in the cranial area during the trot, as determined by thermography.

"This could perhaps indicate that the blood flow of horses longed at the trot in the hyperflexed position may be a little bit disturbed compared to that of horses longed in the normal head and neck position; this is certainly a point for discussion," she said, adding that the temperature variation could even just be caused by the wrinkling of the skin in that area during hyperflexion