Burke J R, Schutten M C, Koceja D M, Kamen G
Motor Control Laboratory, Indiana University, IN, USA.
Arch Phys Med Rehabil. 1996 Jun;77(6):600-4. doi: 10.1016/s0003-9993(96)90302-0.
To explore possible effects of aging on the excitability of spinal reflexes.
Using a cross-sectional design, the influences of muscle vibration and the Jendrassik maneuver on patellar tendon reflex function were compared between 30 young adults and 15 older adults.
Motor control research laboratory.
The young adults were volunteers of college age. The older adults (74.5 +/- 4.14 yr) were volunteers from the local community. All subjects were free of medications and neurological conditions that would affect normal neuromuscular responses.
A force-time curve analysis of the patellar tendon reflex response was used to assess the inhibition and facilitation of spinal reflexes. In the experimental protocol to assess spinal reflex inhibition, 100 Hz vibration was applied to the right quadriceps muscle. In another experimental protocol, spinal reflex facilitation was assessed using the Jendrassik maneuver. To perform the Jendrassik maneuver, subjects were instructed to grasp their hands together and to pull as hard as possible while breathing normally. After a 2-second count, the tendon tap was delivered to the right leg and the subject was instructed to relax. In both experimental protocols, control patellar tendon reflexes were collected.
Analysis of variance for reflex peak force revealed a significant 30% reduction in the amount of vibration-induced reflex inhibition with increasing age, and a similar 33% reduction in the amount of Jendrassik maneuver facilitation observed for the older adults as compared with the younger adults.
These results support the hypothesis that inhibitory and excitatory influences acting on the alpha motoneuron pool are different in young and older adults.
探讨衰老对脊髓反射兴奋性可能产生的影响。
采用横断面设计，比较30名年轻成年人和15名老年人中肌肉振动和Jendrassik动作对髌腱反射功能的影响。
运动控制研究实验室。
年轻成年人是大学生志愿者。老年人（74.5±4.14岁）是当地社区的志愿者。所有受试者均未服用会影响正常神经肌肉反应的药物，也没有神经方面的疾病。
对髌腱反射反应进行力-时曲线分析，以评估脊髓反射的抑制和易化作用。在评估脊髓反射抑制的实验方案中，对右侧股四头肌施加100Hz的振动。在另一个实验方案中，使用Jendrassik动作评估脊髓反射易化作用。进行Jendrassik动作时，指导受试者双手紧握并在正常呼吸的同时尽可能用力拉扯。数2秒后，轻敲右侧腿部的肌腱，并指导受试者放松。在两个实验方案中，均采集对照髌腱反射。
对反射峰值力的方差分析显示，随着年龄增长，振动诱发的反射抑制量显著降低30%，与年轻成年人相比，老年人中观察到的Jendrassik动作易化量也有类似的33%的降低。
这些结果支持以下假设，即作用于α运动神经元池的抑制性和兴奋性影响在年轻人和老年人中有所不同。
