Effect of a single osteopathic manipulation on the sacroiliac joint in sport horses with sacroiliac dysfunction

This study aimed to evaluate the effects of a single osteopathic manipulation on the dysfunctional sacroiliac joint (SIJ) of sport horses using osteopathic functional assessment (OFA), visual lameness evaluation and objective gait analysis. Randomised controlled clinical trial, 29 sport horses with SIJ dysfunction with fixation in extension were divided into a treatment group TG (n=21) and a control group CG (n=8). TG received a single osteopathic manipulation (OM) targeting the fixated SIJ, while CG received no intervention. Objective gait analysis was performed using inertial measurement units: pre-intervention, post-intervention (15 minutes, 3 days, and 15 days). Subjective lameness score and osteopathic physical score (including pain and tone evaluation) were also performed. Generalised linear mixed models were used to analyse the results. Osteopathic manipulation significantly reduced epaxial back muscles tone, back pain, and SIJ pain in the treated horses, persisting up to 15 days post-intervention. Objective gait analysis at canter revealed a significant reduction in hind limb protraction (in degrees) (F(1,3)< 3.432, P=0.01); confidence intervals: TG: before (28.44,32.08), post OM 15 min (27.57,31.19), day 3 (26.16,29.81), day 15 (27.10,30.74); and CG before (23.40,29.77), post OM 15 min (25.07,31.69), day 3 (26.02,32.10), day 15 (25.95,32.08); and a significant increase in hind limb retraction (F(1,3)< 3.681, P=0.013); confidence intervals: TG: before (-33.12,-27.57), post OM 15 min (-34.09,-28.56), day 3 (-34.53,-28.98), day 15 (-34.24,-28.70); and CG: before (-40.92,-31.27), post OM 15 min (-39.62,-29.78), day 3 (-37.40,-27.96), day 15 (-37.31,-27.83), especially when cantering towards the affected side. A single osteopathic manipulation of the dysfunctional SIJ in sport horses resulted in small but significant changes in gait parameters and osteopathic functional scoring, including reduced back muscles’pain and tone. Further research is needed to evaluate the impact of equine osteopathic interventions in other locations. • A single osteopathic manipulation targeting dysfunctional sacroiliac joints in sport horses with decreased performance resulted in significant reductions in osteopathic dysfunction, epaxial muscle tone, back pain, and sacroiliac pain that persisted up to 15 days post-treatment. • Most significant biomechanical changes were observed during canter, with increased retraction and decreased protraction of the hindlimb on the affected side when cantering towards the affected direction. This suggests that the sacroiliac joint is more biomechanically challenged during this gait and direction compared to walk or trot, and that osteopathic manipulation may improve mobility and normalize the horse's tendency to keep the thoraco-lumbar back in latero-flexion, ultimately helping to rebalance protraction and retraction patterns. • Objective gait analysis using nine IMUs placed on cannon bones, poll, withers, sacral tuberosity, and coxal tuberosities, is a useful objective tool that allows comprehensive analysis of protraction, retraction, and vertical upperbody displacement parameters during movement at different gaits.