Shirado O, Ito T, Kaneda K, Strax T E
Department of Orthopaedic Surgery, Hokkaido University School of Medicine, Sapporo, Japan.
Arch Phys Med Rehabil. 1995 Mar;76(3):225-9. doi: 10.1016/s0003-9993(95)80605-9.
Posture to avoid hyperextension of the lumbar spine during isometric trunk muscle exercises has been widely recommended. However, there are no common standards for cervical and pelvic alignment during exercises. To investigate the effects of four different techniques regarding cervical and pelvic alignment, electromyographic (EMG) and radiological studies were performed on 30 healthy subjects. The four different postures were: (1) maximally extended neck, (2) neutral neck, (3) maximally flexed neck, and (4) maximally flexed neck with pelvic stabilization through muscle contraction. During flexion exercises, the largest increase in EMG activity in the abdominal muscles was observed with the flexed neck with pelvic stabilization (p < .01). During extensor exercises, the largest increase in EMG activity in the erector spinae was also obtained in the same position (p < .01). An increase of EMG activity in antagonist muscles (eg, erector spinae on flexion, and rectus and oblique muscles on extension) was also greatest with the flexed neck and pelvic stabilization. From the radiographic study, degrees of lumbar lordosis were least with the flexed neck and pelvic stabilization (p < .01). This study showed that neck and pelvic alignment can influence the EMG activity of trunk flexors and extensors during isometric trunk exercises. For isometric trunk muscle exercises, a maximum flexed neck with pelvic stabilization through muscle contraction seems to be the most optimal posture for decreasing the lumbar lordosis and for activating trunk flexors and extensors most effectively.
在等长躯干肌肉锻炼期间，人们广泛推荐采用避免腰椎过度伸展的姿势。然而，在锻炼过程中，颈椎和骨盆对齐并没有通用标准。为了研究四种不同的颈椎和骨盆对齐技术的效果，对30名健康受试者进行了肌电图（EMG）和放射学研究。四种不同的姿势分别是：（1）颈部最大程度伸展，（2）颈部中立位，（3）颈部最大程度屈曲，以及（4）通过肌肉收缩实现骨盆稳定的颈部最大程度屈曲。在屈曲锻炼期间，通过肌肉收缩实现骨盆稳定的颈部屈曲姿势下，观察到腹部肌肉的肌电图活动增加幅度最大（p <.01）。在伸展锻炼期间，在相同姿势下竖脊肌的肌电图活动增加幅度也最大（p <.01）。拮抗肌的肌电图活动增加（例如，屈曲时的竖脊肌，伸展时的直肌和斜肌）在颈部屈曲和骨盆稳定时也最为明显。从放射学研究来看，通过肌肉收缩实现骨盆稳定的颈部屈曲姿势下腰椎前凸程度最小（p <.01）。这项研究表明，在等长躯干锻炼期间，颈椎和骨盆对齐会影响躯干屈肌和伸肌的肌电图活动。对于等长躯干肌肉锻炼，通过肌肉收缩实现骨盆稳定的最大程度屈曲颈部姿势似乎是减少腰椎前凸以及最有效地激活躯干屈肌和伸肌的最佳姿势。
