Vezina M J, Hubley-Kozey C L
Canadian Forces Health Care Center Support Unit, Ottawa, Ontario.
Arch Phys Med Rehabil. 2000 Oct;81(10):1370-9. doi: 10.1053/apmr.2000.16349.
To evaluate the relative activation amplitudes from 3 abdominal and 2 trunk extensor muscle sites in healthy subjects performing the pelvic tilt, abdominal hollowing, and level 1 of the trunk stability test (TST level 1) exercises and to compare the activation amplitudes among muscle sites and exercises.
Prospective comparative study.
Motion Analysis Research Center, Dalhousie University, Canada.
Twenty-four healthy men (mean age, 30 +/- 8.1 yr [SD]) without low back pain.
Subjects performed 3 exercises in a balanced order, repeating each exercise 5 times while surface electromyography (EMG) was recorded from the 5 muscle sites. Exercises were divided into 2 phases: movement and stabilization. The root-mean-square amplitude of the EMG for each phase was calculated and normalized to the maximal voluntary isometric contraction (MVIC) amplitude for each muscle. A 2-factor repeated-measures analysis of variance (ANOVA) tested the muscle by exercise interaction and the main effects for each phase separately.
Normalized activation amplitude was the main dependent variable. Ensemble-average curves were calculated to examine the phasing of activation.
ANOVA showed a statistically significant interaction (p < .05) for both phases, indicating the 3 exercises recruited the 5 muscle sites using different patterns of relative activation. The external oblique (EO) muscle site was activated to higher amplitudes than the other 4 sites in all 3 exercises for both phases. The highest activity was recorded from the EO during the pelvic tilt, just more than 25% of MVIC. The only exercise to recruit the erector spinae to significantly higher amplitudes than the multifidus site was the TST level 1.
Study exercises were not interchangeable for the patterns of trunk muscle activation amplitudes. The exercises did not recruit the abdominal muscles to adequate levels for strengthening for this healthy sample; however, all 5 muscle sites were activated, forming the basis of a stabilizing exercise approach.
评估健康受试者在进行骨盆倾斜、收腹以及躯干稳定性测试1级（TST 1级）练习时，3个腹部肌肉部位和2个躯干伸肌部位的相对激活幅度，并比较各肌肉部位和练习之间的激活幅度。
前瞻性比较研究。
加拿大达尔豪斯大学运动分析研究中心。
24名无腰痛的健康男性（平均年龄30±8.1岁[标准差]）。
受试者以平衡的顺序进行3项练习，每项练习重复5次，同时从5个肌肉部位记录表面肌电图（EMG）。练习分为两个阶段：运动和稳定。计算每个阶段EMG的均方根幅度，并将其归一化为每个肌肉的最大自主等长收缩（MVIC）幅度。采用双因素重复测量方差分析（ANOVA）分别测试肌肉与练习的交互作用以及每个阶段的主效应。
归一化激活幅度是主要因变量。计算总体平均曲线以检查激活的相位。
ANOVA显示两个阶段均存在统计学显著的交互作用（p < 0.05），表明这3项练习以不同的相对激活模式募集5个肌肉部位。在两个阶段的所有3项练习中，腹外斜肌（EO）部位的激活幅度均高于其他4个部位。在骨盆倾斜期间，EO记录到的活动最高，略超过MVIC的25%。唯一能使竖脊肌募集幅度显著高于多裂肌部位的练习是TST 1级。
对于躯干肌肉激活幅度模式而言，研究中的练习不可相互替代。对于这个健康样本，这些练习未能使腹部肌肉募集到足够强度以达到强化效果；然而，所有5个肌肉部位均被激活，构成了稳定练习方法的基础。
