Zsoldos R R, Krüger B, Licka T F
Movement Science Group Vienna, Clinical Department of Small Animals and Horses, University of Veterinary Medicine Vienna, Veterinaerplatz 1, 1210, Vienna, Austria.
Multimedia, Simulation and Virtual Reality Group, Institute of Computer Science II, University of Bonn, Friedrich-Ebert-Allee 144, 53113, Bonn, Germany.
Comp Exerc Physiol. 2014;10(2):75-88. doi: 10.3920/CEP140001. Epub 2014 Jul 7.
In vertebrates ageing is characterized by reduced viscoelasticity of the ligamentous and tendineous structures and fibre changes in muscle. Also, some vertebral joint degeneration develops with ageing. The aim of this study was to apply dynamic time warping to compare the temporal characteristics of the surface electromyography (sEMG) data and to illustrate the differences in the pattern of muscle use during tasks of daily life in old and mature horses. kinematics (24 skin markers) and sEMG measurements of neck extensors and flexors were taken in five mature horses (age 10 ± 2 years, half of mean life expectancy) and five old horses (age 25 ± 5 years, older than the mean life expectancy). All horses had the same level of activity in the 12 months prior to the measurement. Tasks measured were neck flexion and neck extension as well as neutral neck position. Muscle activation, minimum and maximum muscle activation were collected. Quartiles of muscle activity based on the maximum observed activity of each muscle were calculated to document the relative increase of activity level during the task. Kinematics as well as overall muscle activity patterns were similar across horses and age groups. However, in the neutral position old horses showed increased extensor activity compared to mature horses, indicating that old equine muscle requires more activity to counteract gravity. Dynamic time warping specified optimal temporal alignments of time series, and different temporal performances were identified. The age groups differed during the flexion task, while extension and neutral were more similar. The results of this study show that even in the second half of life and in the absence of muscle disuse the muscular strategy employed by horses continues to be adapted.
在脊椎动物中，衰老的特征是韧带和肌腱结构的粘弹性降低以及肌肉纤维变化。此外，一些脊椎关节退变也会随着年龄增长而出现。本研究的目的是应用动态时间规整来比较表面肌电图（sEMG）数据的时间特征，并阐明老年马和成年马在日常生活任务中肌肉使用模式的差异。对5匹成年马（年龄10±2岁，平均寿命的一半）和5匹老年马（年龄25±5岁，超过平均寿命）进行了颈部伸肌和屈肌的运动学（24个皮肤标记）和sEMG测量。所有马匹在测量前12个月的活动水平相同。测量的任务包括颈部屈曲、颈部伸展以及颈部中立位。收集肌肉激活、最小和最大肌肉激活情况。根据每块肌肉观察到的最大活动计算肌肉活动的四分位数，以记录任务期间活动水平的相对增加。不同马匹和年龄组的运动学以及整体肌肉活动模式相似。然而，在中立位时，老年马与成年马相比伸肌活动增加，这表明老年马的肌肉需要更多活动来抵消重力。动态时间规整确定了时间序列的最佳时间对齐方式，并识别出了不同的时间表现。在屈曲任务中年龄组存在差异，而伸展和中立位则更为相似。本研究结果表明，即使在生命的后半期且不存在肌肉废用的情况下，马所采用的肌肉策略仍在持续适应。
