Effect of induced back pain on gait and performance of trotting horses.

This research article investigates the impact of induced back pain on the gait and performance of trotting horses. The study found that back pain, induced through intramuscular injections of a lactic acid solution, resulted in no significant changes in the horse’s gait, but did reduce performance capacity and caused stiffness in the horse’s spine.

Research Methodology

• The research involved inducing back pain in Standardbred horses. This was accomplished by administering multiple intramuscular injections of a concentrated lactic acid solution into the left longissimus dorsi muscle, which is a large muscle on the horse’s back.
• This study was divided into two parts. In the first stage, two trotters were exercised on a treadmill and filmed before and after the induction of back pain using high speed cinematography. In the second stage, a more intensive clinical and cinematic analysis was conducted on three horses.

Findings and Observations

• The first stage of the study showed that even after inducing back pain, there were no signs of hindlimb lameness in the horses. Lameness in the hindlimbs, a condition which often results in changes to a horse’s gait, would be a clear indication that the inflicted back pain was affecting their performance. Despite this, no quantitative changes in the gait components were observed.
• An unexpected finding from the first stage of the study was that there was a noticeable reduction in performance capacity. This was determined by comparing the horse’s performance on the treadmill before and after the induction of back pain.
• The second stage of the research, which involved a more intensive clinical and cinematic analysis of three additional horses, yielded similar results. There were some minor changes detected in their stride pattern, but no apparent disturbances in gait were produced.
• The main effect observed in the horses after inducing back pain was stiffness in the thoracolumbar spine and an inability to perform at fast-paces. The thoracolumbar spine is located in the middle of the horse’s back, spanning the area between the chest (thoracic) and lower back (lumbar) regions.

Conclusion

• Overall, the study concludes that while induced back pain does not seem to significantly alter a horse’s gait, it does affect their overall performance. Specifically, it causes stiffness in the thoracolumbar spine and restricts their ability to trot at fast paces.