Reisbig Nathalie A, Pifko Justin, Lanovaz Joel L, Weishaupt Michael A, Carmalt James L
Department of Large Animal Clinical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK, Canada.
College of Kinesiology, University of Saskatchewan, Saskatoon, SK, Canada.
Front Vet Sci. 2023 Jun 19;10:1213423. doi: 10.3389/fvets.2023.1213423. eCollection 2023.
Although the temporomandibular joint (TMJ) is the major contact point between the reins in the riders' hand, the bit in the mouth, and the rest of the horse under saddle, the role of inflammation of this joint on equine locomotion and rein tension is unknown.
To determine the effect of acute TMJ inflammation on rein-tension and horse movement when horses were long-reined on a treadmill.
A randomized, controlled, cross-over design.
Five horses were trained by one clinician to walk and trot on a treadmill wearing long-reining equipment instrumented with a rein-tension device and reflective optical tracking markers. Subjective assessment of horse's dominant side, and movement, were determined without rein-tension (free walk and trot); and with rein-tension (long-reined walk and trot). Continuous rein-force data from both sides were collected over ~60s from each trial. Movement was recorded using a 12-camera optical motion capture system. One randomly assigned TMJ was subsequently injected with lipopolysaccharide and the treadmill tests repeated by investigators blinded to treatment side. A second, identical assessment was performed 10 days later with the opposite TMJ being the target of intervention.
All horses showed reduced rein-tension on the injected (inflamed) side. Increased rein-tension was required on the non-injected side at trot, to maintain them in the correct position on the treadmill post-injection. The only kinematic variable to show any significant change due to rein tension or TMJ inflammation during the walk or trot was an increase in forward head tilt in the presence of rein tension in the trot after injection.
Low number of horses and investigation of response to acute inflammation only.
TMJ inflammation changed, subjectively and objectively, the response to rein-input, but the horses did not become lame.
虽然颞下颌关节（TMJ）是骑手手中缰绳、马口中衔铁与马鞍下马匹身体其他部位之间的主要接触点，但该关节炎症对马的运动和缰绳张力的作用尚不清楚。
确定马匹在跑步机上进行长缰绳训练时，急性颞下颌关节炎症对缰绳张力和马匹运动的影响。
随机对照交叉设计。
由一名临床医生训练五匹马，使其戴着装有缰绳张力装置和反光光学跟踪标记的长缰绳设备在跑步机上行走和小跑。在无缰绳张力（自由行走和小跑）以及有缰绳张力（长缰绳行走和小跑）的情况下，对马的优势侧和运动进行主观评估。每次试验在约60秒内收集两侧的连续缰绳张力数据。使用12台摄像机的光学运动捕捉系统记录运动情况。随后随机选择一个颞下颌关节注射脂多糖，并由对治疗侧不知情的研究人员重复进行跑步机测试。10天后进行第二次相同的评估，对另一侧颞下颌关节进行干预。
所有马匹在注射（发炎）侧的缰绳张力均降低。在小跑时，非注射侧需要增加缰绳张力，以使其在注射后在跑步机上保持正确位置。在行走或小跑过程中，由于缰绳张力或颞下颌关节炎症而显示出任何显著变化的唯一运动学变量是注射后小跑时存在缰绳张力的情况下，头部前倾角增加。
马匹数量少且仅研究了对急性炎症的反应。
颞下颌关节炎症在主观和客观上改变了对缰绳输入的反应，但马匹并未跛行。
