Comparison of the Prevalence and Location of Trigger Points in Dressage and Show-Jumping Horses.

Myofascial trigger points (MTrPs) are localized, hypersensitive areas in muscles that can cause pain and reduced performance. This study aimed to compare the prevalence and location of MTrPs in show-jumping and dressage horses. A secondary objective was to evaluate the potential of thermography, pressure algometry, and facial expression scoring in characterizing MTrPs in horses. Fourteen horses (seven dressage, seven show-jumping) were examined. Muscle palpation was used to identify MTrPs. Thermography was used to compare the skin surface temperature of MTrPs with adjacent control areas. Additionally, facial expressions were recorded during palpation and scored by three blinded observers using the Horse Grimace Scale (HGS). MTrPs were found in all horses. Both groups showed a high prevalence (>60%) of MTrPs in the back. Dressage horses had a higher prevalence of MTPrs in the neck (17%) and a lower prevalence in the rump (17%) than show-jumping horses (3% and 30%, respectively). Temperatures at MTrP sites were significantly higher than at control points (p < 0.01). Facial expression scores were also significantly higher during MTrP palpation compared to control (16 [0-24] vs. 6 [0-19], p = 0.004). These findings open a perspective for better recognition and treatment of myofascial pain in athletic horses.