Department of Physical Therapy, Saitama Prefectural University, Saitama, Japan.
Med Sci Monit. 2013 Apr 29;19:309-16. doi: 10.12659/MSM.883897.
Motor nerve function decreases with age and can cause abnormalities in motor function. Using newly designed methods, we used evoked electromyograms to evaluate change in motor nerve function.
Motor function was assessed by grip strength, timed up-and-go test, 5-m normal walk, and 5-m fastest walk. In addition, motor nerve conduction velocity was calculated by measuring latency differences (NCV) in elderly and young subjects. We also investigated motor nerve conduction velocity by correlation coefficient (NCVCC) and the difference between NCV and NCVCC (DNCV).
Significant differences were observed in the motor function of elderly and young persons in grip strength, the timed up-and-go test, and the 5-m fastest walk; however, no difference was observed in the 5-m normal walk test. NCVCC was lower than NCV in both elderly and young. The correlation coefficient peak of the NCVCC calculation was lower in elderly than in young. A negative correlation was observed between correlation coefficient peak and DNCV in elderly subjects.
NCVCC compares the overall shape of compound muscle action potential and reflects not only the fastest motor unit, but also the motor nerve conduction velocity of other motor unit components. A significant negative correlation between DNCV and the correlation coefficient peak was observed only in elderly subjects, suggesting that older individuals, including those that maintain a high level of physical strength, experience a loss of motor nerve function. Thus, changes in motor nerve function among elderly persons can potentially be further examined for clinical use.
运动神经功能随年龄增长而下降，可能导致运动功能异常。我们采用新设计的方法，利用诱发电位肌电图评估运动神经功能的变化。
通过握力、计时起立行走测试、5 米正常行走和 5 米最快行走评估运动功能。此外，通过测量老年和青年受试者潜伏期差异（NCV）计算运动神经传导速度。我们还通过相关系数（NCVCC）和 NCV 与 NCVCC 之间的差值（DNCV）研究运动神经传导速度。
在握力、计时起立行走测试和 5 米最快行走方面，老年组和青年组的运动功能存在显著差异；而在 5 米正常行走测试中则无差异。NCVCC 在老年组和青年组均低于 NCV。NCVCC 计算的相关系数峰值在老年组低于青年组。老年受试者的相关系数峰值与 DNCV 呈负相关。
NCVCC 比较复合肌肉动作电位的整体形态，不仅反映最快的运动单位，还反映其他运动单位成分的运动神经传导速度。仅在老年受试者中观察到 DNCV 与相关系数峰值之间存在显著负相关，表明包括那些保持高体力水平的老年人在内，运动神经功能均有一定程度的丧失。因此，进一步检查老年人运动神经功能的变化可能具有临床意义。
