Kadhiresan V A, Guelinckx P J, Faulkner J A
Department of Physiology, University of Michigan Medical School, Ann Arbor 48109-2007.
J Appl Physiol (1985). 1993 Sep;75(3):1294-9. doi: 10.1152/jappl.1993.75.3.1294.
The functional properties of latissimus dorsi (LTD) muscles were evaluated 160 to 180 days after tenotomy and repair, when grafts had stabilized. Our hypothesis was that, compared with control LTD muscles, LTD grafts would develop less absolute force and power but that the specific force and normalized power would not differ. Expressed as a percentage of the value for control LTD muscles, values for grafts were 67% for muscle mass, 74% for mean single fiber cross-sectional area, 56% for maximum absolute isometric tetanic force, 64% for maximum absolute average force during shortening, and 70% for maximum absolute power. Compared with control LTD muscles, grafts showed no significant differences either in the number of fibers in the total muscle cross section or in the optimum velocity for the development of power. When force and power of grafts were normalized for total fiber cross-sectional area and mass, respectively, only the value for maximum specific force (84% of control value) was significant. The mechanisms responsible for the decrease in specific force after tenotomy and repair are not known. In contrast to the deficit in maximum specific force, the 30% deficit in maximum absolute power of grafts compared with control LTD muscles was explained completely by the 33% smaller muscle mass.
在肌腱切断和修复术后160至180天，当移植物稳定时，对背阔肌（LTD）的功能特性进行了评估。我们的假设是，与对照LTD肌肉相比，LTD移植物产生的绝对力和功率会更低，但比肌力和标准化功率不会有差异。以对照LTD肌肉的值的百分比表示，移植物的肌肉质量值为67%，平均单纤维横截面积值为74%，最大绝对等长强直收缩力值为56%，缩短过程中最大绝对平均力值为64%，最大绝对功率值为70%。与对照LTD肌肉相比，移植物在总肌肉横截面积中的纤维数量或功率发展的最佳速度方面均无显著差异。当分别将移植物的力和功率按总纤维横截面积和质量进行标准化时，只有最大比肌力值（对照值的84%）具有显著性。肌腱切断和修复后比肌力下降的机制尚不清楚。与最大比肌力的不足相反，与对照LTD肌肉相比，移植物最大绝对功率30%的不足完全是由肌肉质量小33%所解释的。
