Powell P L, Roy R R, Kanim P, Bello M A, Edgerton V R
J Appl Physiol Respir Environ Exerc Physiol. 1984 Dec;57(6):1715-21. doi: 10.1152/jappl.1984.57.6.1715.
The maximum tetanic tension (Po) generated by a skeletal muscle is determined by its functional cross-sectional area (CSA) and its specific tension (tension/CSA). Measurements of average fiber length (normalized to a sarcomere length of 2.2 micron), muscle mass, and approximate angle of pinnation of muscle fibers within a muscle were taken from 26 different guinea pig hindlimb muscles and were used to calculate CSA. The specific tension was assumed to be 22.5 N X cm-2 and was used to determine the estimated Po of each muscle studied. In a second group of guinea pigs the in situ Po of 11 selected hindlimb muscles and muscle groups were determined. Estimated and measured Po values were found to have a strong linear relationship (r = 0.99) for muscle and muscle groups tested. The specific tension of the soleus, a homogeneously slow-twitch muscle, was shown to be approximately 15.4 N X cm-2 (P less than 0.01). Therefore, in our hands a specific tension value of 22.5 N X cm-2 appears to be a reasonable value for all mixed muscles studied in the guinea pig hindlimb and can be used to estimate their Po.
骨骼肌产生的最大强直张力（Po）由其功能横截面积（CSA）及其比张力（张力/CSA）决定。从26块不同的豚鼠后肢肌肉中测量了平均纤维长度（标准化为肌节长度2.2微米）、肌肉质量以及肌肉内肌纤维的大致羽状角，并用于计算CSA。假定比张力为22.5 N×cm-2，用于确定所研究的每块肌肉的估计Po。在第二组豚鼠中，测定了11块选定的后肢肌肉和肌肉群的原位Po。对于所测试的肌肉和肌肉群，发现估计的和测量的Po值具有很强的线性关系（r = 0.99）。比目鱼肌是一种均匀的慢肌，其比张力约为15.4 N×cm-2（P＜0.01）。因此，在我们的研究中，22.5 N×cm-2的比张力值对于豚鼠后肢中所有混合肌肉来说似乎是一个合理的值，可用于估计它们的Po。
