Electromyographic activity of the lower body muscles during the deadlift and stiff-legged deadlift

The purpose of this study was to analyze eletromyographic (EMG) signal of biceps femoris (BF), vastus
lateralis (VL), lumbar multifidus (LM), anterior tibialis (AT), and medial gastrocnemius (MG) during the deadlift (DL) and stiff-legged deadlift (SLDL). Fourteen men (26.71 ± 4.99 yrs; body mass 88.42 ± 12.39 kg; 177.71 ± 8.86 cm) voluntarily participated in this study. The data were obtained on three non-consecutive days separated by 48 hrs. In the first day, anthropometric measures and the repetition maximum testing (1 RM) for both exercises were applied in a counter-balanced cross-over design. On the second day, the 1 RM was re-tested. On the third day, both exercises were performed at 70% of 1 RM and the EMG data were collected. Parameters related to the RMS during the movement, temporal activation patterns, and relative times of activation were analyzed for each muscle. The maximum activation
level for VL during the DL (128.3 ± 33.9% of the EMG peak average) was significantly different (P = 0.027) from the SLDL (101.1 ± 14% of the EMG peak average). These findings should be useful when
emphasizing different muscle groups in a resistance training program.

本研究旨在分析在硬拉（DL）和固定腿硬拉（SLDL）过程中股二头肌（BF）、阔筋膜张肌（VL）、腰背肌（LM）、胫骨前肌（AT）和内腓肠肌（MG）的肌电图（EMG）信号。十四名男性（平均年龄26.71 ± 4.99岁；体重88.42 ± 12.39公斤；身高177.71 ± 8.86厘米）自愿参与本研究。数据在相隔48小时的三个非连续日获得。第一天，采用交叉设计进行体质测量和两项运动的重复最大测试（1 RM）。第二天，对1 RM进行再次测试。第三天，在1 RM的70%强度下进行两项运动，并收集EMG数据。对每个肌肉在运动过程中的均方根（RMS）相关参数、时间激活模式和激活相对时间进行了分析。在硬拉过程中VL的最大激活水平（EMG峰值平均的128.3 ± 33.9%）与固定腿硬拉（EMG峰值平均的101.1 ± 14%）存在显著差异（P = 0.027）。这些发现对于在抗阻训练计划中强调不同肌肉群时应具有参考价值。