de Boer Maarten D, Seynnes Olivier R, di Prampero Pietro E, Pisot Rado, Mekjavić Igor B, Biolo Gianni, Narici Marco V
Instititute for Biomedical Research into Human Movement and Health, Manchester Metropolitan University, Alsager, ST7 2HL, UK.
Eur J Appl Physiol. 2008 Sep;104(2):401-7. doi: 10.1007/s00421-008-0703-0. Epub 2008 Mar 5.
The aim of the present study was to investigate the changes in thickness, fascicle length (L (f)) and pennation angle (theta) of the antigravity gastrocnemius medialis (GM) and vastus lateralis (VL) muscles, and the non-antigravity tibialis anterior (TA) and biceps brachii (BB) muscles measured by ultrasonography in ten healthy males (aged 22.3 +/- 2.2 years) in response to 5 weeks of horizontal bed rest (BR). After BR, muscle thickness decreased by 12.2 +/- 8.8% (P < 0.05) and 8.0 +/- 9.1% (P < 0.005) in the GM and VL, respectively. No changes were observed in the TA and BB muscles. L (f) and theta decreased by 4.8 +/- 5.0% (P < 0.05) and 14.3 +/- 6.8% (P < 0.005) in the GM and by 5.9 +/- 5.3% (P < 0.05) and 13.5 +/- 16.2% (P < 0.005) in the VL, again without any changes in the TA and BB muscles. The finding that amongst the antigravity muscles of the lower limbs, the GM deteriorated to a greater extent than the VL is possibly related to the differences in relative load that this muscle normally experiences during daily loading. The dissimilar response in antigravity and non-antigravity muscles to unloading likely reflects differences in loading under normal conditions. The significant structural alterations of the GM and VL muscles highlight the rapid remodelling of muscle architecture occurring with disuse.
本研究的目的是调查通过超声测量，十名健康男性（年龄22.3±2.2岁）在经历5周水平卧床休息（BR）后，抗重力的内侧腓肠肌（GM）和外侧股四头肌（VL）以及非抗重力的胫骨前肌（TA）和肱二头肌（BB）的厚度、肌束长度（L(f)）和羽状角（θ）的变化。BR后，GM和VL的肌肉厚度分别下降了12.2±8.8%（P<0.05）和8.0±9.1%（P<0.005）。TA和BB肌肉未观察到变化。GM的L(f)和θ分别下降了4.8±5.0%（P<0.05）和14.3±6.8%（P<0.005），VL的L(f)和θ分别下降了5.9±5.3%（P<0.05）和13.5±16.2%（P<0.005），TA和BB肌肉同样没有任何变化。下肢抗重力肌肉中，GM比VL退化程度更大，这一发现可能与该肌肉在日常负荷中通常承受的相对负荷差异有关。抗重力和非抗重力肌肉对卸载的不同反应可能反映了正常情况下负荷的差异。GM和VL肌肉的显著结构改变突出了废用导致的肌肉结构快速重塑。
