Kyoto University, Kyoto, Japan.
Eur J Appl Physiol. 2012 Jan;112(1):43-8. doi: 10.1007/s00421-011-1952-x. Epub 2011 Apr 7.
This study investigated the effects of age and inactivity due to being chronically bedridden on atrophy of trunk muscles. The subjects comprised 33 young women (young group) and 41 elderly women who resided in nursing homes or chronic care institutions. The elderly subjects were divided into two groups: independent elderly group who were able to perform activities of daily living involving walking independently (n = 28) and dependent elderly group who were chronically bedridden (n = 13). The thickness of the following six trunk muscles was measured by B-mode ultrasound: the rectus abdominis, external oblique, internal oblique, transversus abdominis, thoracic erector spinae (longissimus) and lumbar multifidus muscles. All muscles except for the transversus abdominis and lumbar multifidus muscles were significantly thinner in the independent elderly group compared with those in the young group. The thicknesses of all muscles in the dependent elderly group was significantly smaller than that in the young group, whereas there were no differences between the dependent elderly and independent elderly groups in the muscle thicknesses of the rectus abdominis and internal oblique muscles. In conclusion, our results suggest that: (1) age-related atrophy compared with young women was less in the deep antigravity trunk muscles than the superficial muscles in the independent elderly women; (2) atrophy associated with chronic bed rest was more marked in the antigravity muscles, such as the back and transversus abdominis.
本研究旨在探讨因长期卧床导致的年龄增长和不活动对躯干肌肉萎缩的影响。研究对象包括 33 名年轻女性（年轻组）和 41 名居住在养老院或慢性病护理机构的老年女性。老年受试者分为两组：能够独立完成包括独立行走在内的日常生活活动的独立老年组（n = 28）和长期卧床的依赖老年组（n = 13）。通过 B 型超声测量以下六块躯干肌肉的厚度：腹直肌、腹外斜肌、腹内斜肌、腹横肌、胸腰伸肌（最长肌）和腰多裂肌。除了腹横肌和腰多裂肌之外，所有肌肉在独立老年组中都明显比年轻组薄。依赖老年组的所有肌肉厚度均明显小于年轻组，而在腹直肌和腹内斜肌的肌肉厚度方面，依赖老年组与独立老年组之间没有差异。总之，我们的结果表明：（1）与年轻女性相比，独立老年女性的深层抗重力躯干肌肉的年龄相关性萎缩程度小于浅层肌肉；（2）与慢性卧床相关的萎缩在背部和腹横肌等抗重力肌肉中更为明显。
