Veldhuizen J W, Verstappen F T, Vroemen J P, Kuipers H, Greep J M
Department of Surgery, University of Limburg, Maastricht, The Netherlands.
Int J Sports Med. 1993 Jul;14(5):283-7. doi: 10.1055/s-2007-1021178.
Immobilization of the knee as part of the treatment in bone or joint lesions leads to atrophy and consequently loss of functionally. In patients this atrophy and loss of functionality is difficult to quantify because of interfering symptoms and missing baseline data. In the present study structural and functional changes in thigh muscles were examined in eight healthy volunteers of whom one leg was immobilized in a cast for four weeks. Quadriceps cross-sectional area determined with computed tomography was 21% +/- 7% diminished after four weeks immobilization (p < 0.05). Muscle biopsies from the musculus vastus lateralis revealed an 16% decreased fiber diameter (p < 0.05) and no significant shift in fiber types. Isokinetic strength measurements of knee extensors and flexors demonstrated a fall in peak torque of 53% +/- 9% and 26% +/- 13% at an angular velocity of 60 deg.s-1 (p < 0.01). Aerobic power in one-leg-cycling exercise was not significantly affected, but isokinetic quadriceps endurance work decreased from 9.1 kJ to 5.6 kJ (p < 0.05). Despite the fall in quadriceps performance the subjects had only minor functional complaints for a few days. It is concluded that immobilization of the knee is an important factor in the development of thigh muscle atrophy in patients and should therefore be diminished as much as possible.
作为骨或关节损伤治疗的一部分，膝关节固定会导致萎缩，进而导致功能丧失。在患者中，由于干扰症状和缺乏基线数据，这种萎缩和功能丧失难以量化。在本研究中，对八名健康志愿者的大腿肌肉结构和功能变化进行了检查，其中一条腿用石膏固定四周。四周固定后，通过计算机断层扫描测定的股四头肌横截面积减少了21%±7%（p<0.05）。股外侧肌的肌肉活检显示纤维直径减少了16%（p<0.05），纤维类型无明显变化。膝关节伸肌和屈肌的等速力量测量表明，在角速度为60度/秒时，峰值扭矩分别下降了53%±9%和26%±13%（p<0.01）。单腿骑自行车运动中的有氧能力没有受到显著影响，但等速股四头肌耐力工作从9.1千焦降至5.6千焦（p<0.05）。尽管股四头肌性能下降，但受试者在几天内只有轻微的功能主诉。结论是，膝关节固定是患者大腿肌肉萎缩发展的一个重要因素，因此应尽可能减少。
