Study sheds light on hyperflexion
A study published in the Journal of Animal Physiology and Animal Nutrition has revealed more information about the effect of hyperflexion on horses' necks.
In a study conducted by Mareike Becker-Birck in the group of Christine Aurich at the University of Veterinary Medicine in Vienna, the stress levels shown by horses trained on the lunge with their necks either extended forwards or fixed in hyperflexion were compared.
Stress was assessed by monitoring the levels of stress hormones in the animals' saliva and by following the heart rate and the fluctuations in heart rate exhibited before, during and after training. Surface body temperature was also measured before and after, and no whips were used during training.
The results showed that all the horses showed an increase in stress, but less so than when they are transported by road or ridden for the first time - but most importantly, the effects were the same irrespective of whether the animals were lunged under hyperflexion or with their necks extended. The only significant difference observed related to the temperature of the cranial part of the neck, which possibly indicates that blood flow is not quite even when lunged in hyperflexion.
Aurich commented: "Our results show that hyperflexion does not itself harm the animals but some trainers combine it with forceful and aggressive intervention of the rider over prolonged periods of time. This is a different situation from the one we investigated so our study should not be interpreted to mean that hyperflexion never has any stressful or negative effects."