Nijem Ramsey M, Coburn Jared W, Brown Lee E, Lynn Scott K, Ciccone Anthony B
Department of Kinesiology, Center for Sport Performance, California State University, Fullerton, California.
J Strength Cond Res. 2016 May;30(5):1177-82. doi: 10.1519/JSC.0000000000001351.
The purpose of this study was to determine the effects of deadlift chain variable resistance on surface electromyography (EMG) of the gluteus maximus, erector spinae, and vastus lateralis muscles, ground reaction forces (GRFs), and rate of force development (RFD). Thirteen resistance-trained men (24.0 ± 2.1 years, 179.3 ± 4.8 cm, 87.0 ± 10.6 kg) volunteered for the study. On day 1, subjects performed 1 repetition maximum (1RM) testing of the deadlift exercise. On day 2, subjects performed one set of 3 repetitions with a load of 85% 1RM with chains (CH) and without chains (NC). The order of the CH and NC conditions was randomly determined for each subject. For the CH condition, the chains accounted for approximately 20% (19.9 ± 0.6%) of the 85% 1RM load, matched at the top of the lift. Surface EMG was recorded to differentiate muscle activity between conditions (CH, NC), range of motion (ROM; bottom, top), and phase (concentric, eccentric). Peak GRFs and RFD were measured using a force plate. Electromyography results revealed that for the gluteus maximus there was significantly greater EMG activity during the NC condition vs. the CH condition. For the erector spinae, EMG activity was greater at the bottom than the top ROM (p ≤ 0.05). Force plate results revealed that deadlifting at 85% 1RM with an accommodating chain resistance of approximately 20% results in a reduction in GRFs (p ≤ 0.05) and no change in RFD (p > 0.05). Collectively, these results suggest that the use of chain resistance during deadlifting can alter muscle activation and force characteristics of the lift.
本研究的目的是确定硬拉链条可变阻力对臀大肌、竖脊肌和股外侧肌的表面肌电图（EMG）、地面反作用力（GRF）以及力发展速率（RFD）的影响。13名有阻力训练经验的男性（24.0±2.1岁，179.3±4.8厘米，87.0±10.6千克）自愿参与本研究。在第1天，受试者进行硬拉练习的1次最大重复量（1RM）测试。在第2天，受试者分别使用链条（CH）和不使用链条（NC），以85% 1RM的负荷进行一组3次重复动作。每个受试者的CH和NC条件顺序是随机确定的。对于CH条件，链条在动作顶端匹配时，约占85% 1RM负荷的20%（19.9±0.6%）。记录表面肌电图以区分不同条件（CH、NC）、运动范围（ROM；底部、顶部）和阶段（向心、离心）之间的肌肉活动。使用测力台测量峰值GRF和RFD。肌电图结果显示，对于臀大肌，NC条件下的肌电活动显著大于CH条件。对于竖脊肌，底部的肌电活动大于顶部ROM（p≤0.05）。测力台结果显示，在85% 1RM下进行硬拉，使用约20%的适应性链条阻力会导致GRF降低（p≤0.05），而RFD无变化（p>0.05）。总体而言，这些结果表明在硬拉过程中使用链条阻力可以改变举重时的肌肉激活和力量特征。
