Larsson L, Grimby G, Karlsson J
J Appl Physiol Respir Environ Exerc Physiol. 1979 Mar;46(3):451-6. doi: 10.1152/jappl.1979.46.3.451.
Maximum values for isometric strength, dynamic strength, and speed of movement (MEV) in the quadriceps muscle were measured in 114 male subjects who were between 11 and 70 yr. Biopsy samples were taken from the quadriceps muscle in 51 of the subjects (22-65 yr. old). Isometric and dynamic strength increased up to the third decade, remained almost constant to the fifth decade, and then decreased with increasing age. However, no measurable external atrophy of the quadriceps muscle, explaining the decline in strength, could be seen in old age. Histochemical changes in the muscle tissue such as decreased proportion of type II fibers and a selective atrophy of type II fibers, were seen with increasing age. The strength decline in old age was also observed to correlate significantly with the type II fiber area. Multiple regression analyses indicated, however, that mechanisms other than the type II fiber atrophy might be responsible for the decline in strength performance during aging. The implications of these findings are discussed.
对114名年龄在11岁至70岁之间的男性受试者测量了股四头肌的等长力量、动态力量和运动速度（MEV）的最大值。在其中51名受试者（年龄在22岁至65岁之间）身上采集了股四头肌的活检样本。等长力量和动态力量在第三个十年之前增加，在第五个十年之前几乎保持不变，然后随着年龄的增长而下降。然而，在老年时并未观察到股四头肌有可测量的外部萎缩来解释力量的下降。随着年龄的增长，肌肉组织出现了组织化学变化，如II型纤维比例下降和II型纤维选择性萎缩。老年时的力量下降也被观察到与II型纤维面积显著相关。然而，多元回归分析表明，除了II型纤维萎缩之外的其他机制可能是衰老过程中力量表现下降的原因。讨论了这些发现的意义。
