Maton B
Eur J Appl Physiol Occup Physiol. 1980 Feb;43(1):45-55. doi: 10.1007/BF00421355.
Most skeletal muscles include at least two types of MU's. Then, it has been stated that the properties of each MU may imply its specific recruitment in static or dynamic work. To test this hypothesis, the activities of biceps brachii MU's have been recorded during voluntary static contraction followed without any break by dynamic contraction. The MU's activity was recorded by means of wire-electrodes. From 45 tests carried out on 15 normal subjects in which 78 MU's were studied it has been found that: (1) the same MU may discharge both in static and in dynamic work; (2) in both types of work the MU's firing rate and recruitment only depend on the external force. For example, a single MU which does not discharge for a given level of static force will discharge during the following dynamic work, but can also be recruited for a higher level of static force. Thus, it can be said that the qualification "tonic" and "phasic", characterize the MU's twitches and do not imply any static-dynamic differentiation. A comparison has been made between the patterns of MU activity which occur in movement against load and those which have been found in movement against inertia. It is suggested that while the latter are preprogrammed, the former fall under a feed-back control.
大多数骨骼肌至少包含两种类型的运动单位（MU）。此外，有观点认为每个运动单位的特性可能暗示其在静态或动态工作中的特定募集方式。为了验证这一假设，在肱二头肌运动单位进行自愿性静态收缩后紧接着进行动态收缩（中间无间断）的过程中，对其活动进行了记录。运动单位的活动通过线电极进行记录。对15名正常受试者进行了45次测试，研究了78个运动单位，结果发现：（1）同一个运动单位在静态和动态工作中均可放电；（2）在两种工作类型中，运动单位的放电频率和募集仅取决于外力。例如，一个在给定静态力水平下不放电的单个运动单位，在随后的动态工作中会放电，但也可能在更高静态力水平下被募集。因此，可以说“紧张性”和“相位性”这两个限定词描述的是运动单位的抽搐，并不意味着任何静态 - 动态的区别。已对对抗负荷运动中出现的运动单位活动模式与对抗惯性运动中发现的模式进行了比较。结果表明，后者是预先编程的，而前者则受反馈控制。
