Parkkola R, Kujala U, Rytökoski U
Department of Diagnostic Radiology, University Hospital of Turku, Finland.
Eur J Appl Physiol Occup Physiol. 1992;65(5):383-7. doi: 10.1007/BF00243501.
A group of 12 sedentary medical students (1 man and 11 women aged 21-27 years) participated in a strength training programme for the trunk muscles lasting 18 weeks. The maximal isometric flexion and extension forces of the trunk muscles were measured before the training and at 18 weeks by dynamometer. The cross-sectional area of the back muscles, i.e. erector spinae, multifidus and psoas muscles, was measured from magnetic resonance images (spin echo sequence TR/TE 1500/80, slice thickness 10 mm) obtained at the L4-L5 disc level before the training, at 11 and 18 weeks. During training, no significant change in the body mass or body fat content was found. Muscle forces or muscle cross-sectional area were not related to body mass. There was a significant increase in both trunk muscle cross-sectional area (psoas muscle P < 0.001 and back muscles P < 0.01) and trunk muscle forces (flexion and extension forces P < 0.01) during the training but no direct association between the muscle cross-sectional area and strength of the flexors and extensors was detected before or after the training.
一组12名久坐不动的医学生（1名男性和11名年龄在21至27岁之间的女性）参加了一项为期18周的躯干肌肉力量训练计划。在训练前和18周时，使用测力计测量躯干肌肉的最大等长屈伸力。从训练前、11周和18周时在L4-L5椎间盘水平获得的磁共振图像（自旋回波序列TR/TE 1500/80，层厚10毫米）中测量背部肌肉（即竖脊肌、多裂肌和腰大肌）的横截面积。在训练期间，未发现体重或体脂含量有显著变化。肌肉力量或肌肉横截面积与体重无关。训练期间，躯干肌肉横截面积（腰大肌P<0.001，背部肌肉P<0.01）和躯干肌肉力量（屈伸力P<0.01）均显著增加，但在训练前后均未检测到屈肌和伸肌的肌肉横截面积与力量之间存在直接关联。
