Olsen E, FouchÉ N, Jordan H, Pfau T, Piercy R J
Structure and Motion Laboratory, The Royal Veterinary College, London, UK.
Cornell University College of Veterinary Medicine, Ithaca, New York, USA.
Equine Vet J. 2018 Mar;50(2):166-171. doi: 10.1111/evj.12737. Epub 2017 Sep 13.
Agreement among experienced clinicians is poor when assessing the presence and severity of ataxia, especially when signs are mild. Consequently, objective gait measurements might be beneficial for assessment of horses with neurological diseases.
To assess diagnostic criteria using motion capture to measure variability in spatial gait-characteristics and swing duration derived from ataxic and non-ataxic horses, and to assess if variability increases with blindfolding.
Cross-sectional.
A total of 21 horses underwent measurements in a gait laboratory and live neurological grading by multiple raters. In the gait laboratory, the horses were made to walk across a runway surrounded by a 12-camera motion capture system with a sample frequency of 240 Hz. They were made to walk normally and with a blindfold in at least three trials each. Displacements of reflective markers on head, fetlock, hoof, fourth lumbar vertebra, tuber coxae and sacrum derived from three to four consecutive strides were processed and descriptive statistics, receiver operator characteristics (ROC) to determine the diagnostic sensitivity, specificity and area under the curve (AUC), and correlation between median ataxia grade and gait parameters were determined.
For horses with a median ataxia grade ≥2, coefficient of variation for the location of maximum vertical displacement of pelvic and thoracic distal limbs generated good diagnostic yield. The hoofs of the thoracic limbs yielded an AUC of 0.81 with 64% sensitivity and 90% specificity. Blindfolding exacerbated the variation for ataxic horses compared to non-ataxic horses with the hoof marker having an AUC of 0.89 with 82% sensitivity and 90% specificity.
The low number of consecutive strides per horse obtained with motion capture could decrease diagnostic utility.
Motion capture can objectively aid the assessment of horses with ataxia. Furthermore, blindfolding increases variation in distal pelvic limb kinematics making it a useful clinical tool.
在评估共济失调的存在和严重程度时，经验丰富的临床医生之间的一致性较差，尤其是当体征较轻时。因此，客观的步态测量可能有助于评估患有神经系统疾病的马匹。
使用动作捕捉技术评估诊断标准，以测量共济失调和非共济失调马匹的空间步态特征和摆动持续时间的变异性，并评估蒙眼是否会增加变异性。
横断面研究。
共有21匹马在步态实验室接受测量，并由多名评估者进行现场神经学分级。在步态实验室中，让马匹在由12个摄像头组成的动作捕捉系统环绕的跑道上行走，采样频率为240Hz。让它们至少各进行三次正常行走和蒙眼行走。对来自三到四个连续步幅的头部、 fetlock、蹄、第四腰椎、髋结节和骶骨上反射标记的位移进行处理，并确定描述性统计、用于确定诊断敏感性、特异性和曲线下面积（AUC）的受试者操作特征（ROC），以及中位共济失调分级与步态参数之间的相关性。
对于中位共济失调分级≥2的马匹，骨盆和胸部远端肢体最大垂直位移位置的变异系数产生了良好的诊断效果。胸部肢体的蹄部AUC为0.81，敏感性为64%，特异性为90%。与非共济失调马匹相比，蒙眼会加剧共济失调马匹的变异性，蹄标记的AUC为0.89，敏感性为82%，特异性为90%。
通过动作捕捉获得的每匹马连续步幅数量较少，可能会降低诊断效用。
动作捕捉可以客观地辅助评估患有共济失调的马匹。此外，蒙眼会增加骨盆远端肢体运动学的变异性，使其成为一种有用的临床工具。
