Taylor K, Calvey T N
J Anat. 1977 Feb;123(Pt 1):67-76.
In the spinotrapezius muscle of the rat and the mouse approximately equal proportions of A,B and C fibres are present. The spinotrapezius therefore contains a lower proportion of B fibres than are known to be present in soleus, but a higher proportion than in tibialis anterior. These results are consistent with the functional properties of the muscles, for the values for isometric twitch contraction time, the half relaxation time, and the twitch summation frequency of the spinotrapezius are also intermediate between those of soleus and tibialis anterior. The present experiments support the view that the proportion of B fibres to A and C fibres govern the overall functional characteristics of mammalian muscles.
在大鼠和小鼠的斜方肌中，A、B和C纤维的比例大致相等。因此，斜方肌中B纤维的比例低于比目鱼肌中已知的比例，但高于胫骨前肌中的比例。这些结果与肌肉的功能特性一致，因为斜方肌的等长收缩时间、半松弛时间和收缩总和频率的值也介于比目鱼肌和胫骨前肌之间。目前的实验支持这样一种观点，即B纤维与A和C纤维的比例决定了哺乳动物肌肉的整体功能特征。
