White M J, Davies C T, Brooksby P
Q J Exp Physiol. 1984 Oct;69(4):685-91. doi: 10.1113/expphysiol.1984.sp002860.
In four male subjects one leg was immobilized in a full leg cast for 2 weeks. Measurements of the contractile properties of both triceps surae were made before, during and after immobilization. There was a significant increase in the mean twitch time to peak tension (Tc) after 1 week of immobilization from 126 +/- 10 ms to 143 +/- 20 ms (P less than 0.05) and in the half-relaxation time (T1/2r) from 88 +/- 7 ms to 107 +/- 12 ms (P less than 0.01). There were no further significant (P less than 0.1) changes in the twitch characteristics during the second week of immobilization. The strength of a maximal voluntary contraction (m.v.c.) declined by 11% (P less than 0.05) after 1 week and 24% (P less than 0.05) after 2 weeks. Twitch tension, tetanic tension and muscle fatigability were not significantly altered during immobilization. Muscle (plus bone) calf cross-sectional area (A) was reduced by 5% (P less than 0.01) after 1 week and a further 3% (P less than 0.05) after 2 weeks. The Tc and T1/2r of the twitch, m.v.c. and A returned to control values within 2, 7, 4 and 14 d respectively. No significant (P less than 0.01) changes were observed in the mechanical properties of the triceps surae of the contralateral limb during the period of immobilization. The results suggest that short-term voluntary immobilization is associated with atrophy and a diminished capacity of the muscle to develop maximal voluntary force.(ABSTRACT TRUNCATED AT 250 WORDS)
在四名男性受试者中，一条腿用全腿石膏固定2周。在固定前、固定期间和固定后，对双侧小腿三头肌的收缩特性进行了测量。固定1周后，平均单收缩达到峰值张力的时间（Tc）从126±10毫秒显著增加到143±20毫秒（P<0.05），半松弛时间（T1/2r）从88±7毫秒增加到107±12毫秒（P<0.01）。在固定的第二周，单收缩特性没有进一步的显著（P<0.1）变化。最大自主收缩（m.v.c.）的力量在1周后下降了11%（P<0.05），在2周后下降了24%（P<0.05）。在固定期间，单收缩张力、强直张力和肌肉疲劳性没有显著改变。1周后，小腿肌肉（加骨骼）横截面积（A）减少了5%（P<0.01），2周后又减少了3%（P<0.05）。单收缩的Tc和T1/2r、m.v.c.和A分别在2、7、4和14天内恢复到对照值。在固定期间，对侧肢体小腿三头肌的力学性能没有观察到显著（P<0.01）变化。结果表明，短期自愿固定与肌肉萎缩和肌肉产生最大自主力量的能力下降有关。（摘要截短至250字）
