National Research Centre for the Working Environment, Lersø Parkalle 105, DK 2100 Copenhagen, Denmark.
Phys Ther. 2010 Apr;90(4):538-49. doi: 10.2522/ptj.20090167. Epub 2010 Feb 4.
High-intensity resistance training plays an essential role in the prevention and rehabilitation of musculoskeletal injuries and disorders. Although resistance exercises with heavy weights yield high levels of muscle activation, the efficacy of more user-friendly forms of exercise needs to be examined.
The aim of this study was to investigate muscle activation and perceived loading during upper-extremity resistance exercises with dumbbells compared with elastic tubing.
A single-group, repeated-measures study design was used.
Exercise evaluation was conducted in a laboratory setting.
Sixteen female workers (aged 26-55 years) without serious musculoskeletal diseases and with a mean neck and shoulder pain intensity of 7.8 on a 100-mm visual analog scale participated in the study.
Electromyographic (EMG) activity was measured in 5 selected muscles during the exercises of lateral raise, wrist extension, and shoulder external rotation during graded loadings with dumbbells (2-7.5 kg) and elastic tubing (Thera-Band, red to silver resistance). The order of exercises and loadings was randomized for each individual. Electromyographic amplitude was normalized to the absolute maximum EMG amplitude obtained during maximal voluntary isometric contraction and exercise testing. Immediately after each set of exercise, the Borg CR10 scale was used to rate perceived loading during the exercise.
Resistance exercise with dumbbells as well as elastic tubing showed increasing EMG amplitude and perceived loading with increasing resistance. At the individually maximal level of resistance for each exercise-defined as the 3 repetitions maximum-normalized EMG activity of the prime muscles was not significantly different between dumbbells (59%-87%) and elastic tubing (64%-86%). Perceived loading was moderately to very strongly related to normalized EMG activity (r=.59-.92). Limitations The results of this study apply only for exercises performed in a controlled manner (ie, without sudden jerks or high acceleration).
Comparably high levels of muscle activation were obtained during resistance exercises with dumbbells and elastic tubing, indicating that therapists can choose either type in clinical practice. The Borg CR10 can be a useful aid in estimating intensity of individual rehabilitation protocols.
高强度抗阻训练在预防和康复肌肉骨骼损伤和疾病方面起着至关重要的作用。尽管使用重物进行的抗阻运动可以产生高水平的肌肉激活，但需要检查更便于使用的运动形式的效果。
本研究旨在比较哑铃和弹性管在上肢抗阻运动中的肌肉激活和感知负荷。
采用单组、重复测量设计。
在实验室环境中进行运动评估。
16 名女性工人（年龄 26-55 岁），无严重肌肉骨骼疾病，颈肩部疼痛平均强度为 100mm 视觉模拟量表的 7.8 分。
在逐渐增加哑铃（2-7.5kg）和弹性管（Thera-Band，红色到银色阻力）的负荷下进行侧平举、腕伸和肩外旋运动时，测量 5 块选定肌肉的肌电图（EMG）活动。每位个体的运动和负荷顺序均随机。将 EMG 幅度归一化为最大自主等长收缩和运动测试期间获得的绝对最大 EMG 幅度。每次运动后，立即使用 Borg CR10 量表评估运动时的感知负荷。
哑铃和弹性管的抗阻运动均显示随着阻力的增加，EMG 幅度和感知负荷增加。在每项运动的个体最大阻力水平（定义为 3 次重复最大-标准化主要肌肉的 EMG 活动）下，哑铃（59%-87%）和弹性管（64%-86%）之间的标准化 EMG 活动无显著差异。感知负荷与归一化 EMG 活动呈中度至高度相关（r=.59-.92）。局限性：本研究结果仅适用于在受控方式下进行的运动（即，无突然急动或高加速度）。
在使用哑铃和弹性管进行抗阻运动时，可获得相当高的肌肉激活水平，这表明治疗师在临床实践中可以选择任一种类型。Borg CR10 可以成为估计个体康复方案强度的有用辅助工具。
