The way a horse carries its neck is a reliable indicator of back disorders, French research suggests.
The findings of the research, which evaluated the spines of both leisure and riding school horses, have been published in the open-access journal, PLoS ONE.
Clémence Lesimple, Carole Fureix, Emmanuel De Margerie, Emilie Sénèque, and Martine Hausberger, all from the University of Rennes 1, were joined by experienced equine chiropractor Hervé Menguy for the study.
The researchers noted a recent study that revealed important postural differences between two horse populations – leisure horses living outdoors in social groups used for occasional relaxed riding, and riding school horses living in individual boxes used in daily riding lessons with more constraining techniques.
That research revealed important differences between the two groups, in terms of postures both while standing and being led in hand.
“The results showed that, among more global postural differences, the outdoor population showed rounder backs and necks.”
It was suggested that these postural differences may reflect chronic effects of riding techniques on the horses’ movement and muscular development.
In their own study, Lesimple and the other researchers set about evaluating the backs of 18 horses coming from these two types of populations. Nine of the horses evaluated were from a riding school and nine were leisure horses.
The animals received two evaluations, one by an experienced chiropractic practitioner and the other through use of Surface Electromyography (sEMG) along the spine to try to assess its value in detecting vertebral disorders.
They then measured neck roundness on 16 of the 18 horses.
They found a strong correlation between the results of the chiropractic investigations, carried out by Menguy, and the sEMG examinations over the spine.
The sEMG measures at the different locations were strongly correlated all over the spine with the findings of Menguy in terms of back soundness, they said.
They also found that neck postures and muscular activities were strongly correlated.
Horses with concave necks had higher sEMG measures (indicating a back problem) both at precise locations (that is, cervical sites) but also when comparing neck postures to the whole spine muscular activity, highlighting the functioning of horses’ back as a whole.
Strong differences appeared between the two sample groups, they found. Leisure horses were evaluated as having sounder spines, showing lower sEMG measures and rounder necks than the riding school horses.
Neck “roundness” and sEMG measures seemed therefore to be reliable indicators of back disorders, they found.
“This highlights the accuracy of using postural elements to evaluate the animals’ general state and has important implications for animals’ welfare evaluations,” they said.
The researchers found that elevated and concave neck postures were associated with back disorders, based on both the sEMG and chiropractic assessements.
“In the cases of ‘affected’ horses, sEMG measures were higher both at the exact location of the vertebral dysfunction (assessed by the practitioner) and all along the spine.
“sEMG measures and neck postures therefore appeared as potentially fruitful indicators of back disorders, a major issue in this species submitted to different types of riding and management styles.
“Thus, comparisons of horses living in two extreme types of domestic life (including different types of work) revealed that in one (riding school), horses were more prone to have concave necks and back disorders than in the other (leisure horses).”
Citation: Lesimple C, Fureix C, De Margerie E, Sénèque E, Menguy H, et al. (2012) Towards a Postural Indicator of Back Pain in Horses (Equus caballus). PLoS ONE 7(9): e44604. doi:10.1371/journal.pone.0044604
The full study can be read at: http://www.plosone.org/article/info:doi/10.1371/journal.pone.0044604