Preliminary Study of the Effect of manual Chiropractic Treatment on the Laterality of Mechanical Nociceptive Thresholds in Thoroughbred Racehorses by Lucy Goodright
Lucy Goodright is a working committee member of McTimoney Animal Association, specialising in chiropractic, mobilisation and soft tissue techniques. Before training as a McTimoney therapist, Lucy worked as a freelance rider and groom, and was hired as an exercise jockey for Lawney Hill Racing in Aston Rowant, Oxfordshire. During this period Lucy was exposed to the power, fitness and physical demands required of racehorses. Once trained in McTimoney chiropractic, Lucy was eager to research the effects of McTimoney practices on the musculoskeletal tone in racehorses, due to the exercise demands of such equine athletes.
Spinal manipulation using chiropractic techniques aims to improve joint function and the symmetry balance of a musculoskeletal system. Research into the effects of this nature of manipulative technique on horses is limited and therefore presented a perfect opportunity for Lucy to carry out such investigation. Using pressure algometry – an established measure of mechanical nociceptive thresholds (the sensory nervous system’s response to pain or discomfort given pressure) to quantify musculoskeletal responses – Lucy was able to discover the effects of using chiropractic methods on a horse’s spine.
The aim of the research was to accurately assess and compare the influence of manual chiropractic treatment on the left and right-hand-side mechanical nociceptive thresholds measures of the thoracolumbar musculature (superficial muscles of the back) on racehorses who were in training.
Returning to Lawney Hill Racing, Lucy investigated the effects of McTimoney on several of the yard’s racers. Sixteen horses, all in similar training, were selected to take part and were split into two groups of eight. Grooms helped by holding those used in the tests, trotting them up for veterinary inspection to make sure they were sound before being worked on.
Whilst the horses were treated by McTimoney therapist Leigh Miller, Lucy took measurements using a digital pressure algometer. Triplicate mechanical nociceptive thresholds were measured 8-10cm lateral to the dorsal midline at five bilateral anatomical sites (T9, T13, T18, L3 and L6) along the thoracic and lumbar musculature vertebrae. Measurements were taken before treatment, two hours post-treatment and then again at two, seven- and fourteen-days post treatment.
Lucy’s main findings saw a difference with mechanical nociceptive thresholds (for example tail swishing, moving away/backing off, or muscle twitches) between the left and right-hand-sides of the musculature along the spine of the racehorses tested. At various points along the thoracic and lumbar spine the pain threshold increased significantly along the right-hand-side following McTimoney chiropractic treatment, which suggested that this type of procedure reduced pain and sensitivity in the spinal muscles of actively training and racing national hunt and point to point horses. Thus concluding, that manual chiropractic treatment reduces sensitivity to pain along the thoracic and lumbar musculature, with independent laterality effects seen at different sites. Lucy’s research poster was displayed at the Saddle Research Trust annual conference on 8th December 2018.