Murray Nicholas, Cipriani Daniel, O'Rand Denise, Reed-Jones Rebecca
Interdisciplinary Health Sciences, The University of Texas at El Paso, El Paso, TX, USA.
Schmid College of Science and Technology Physical Therapy, Crean School of Health and Life Sciences, Chapman University, Orange, CA, USA.
Int J Exerc Sci. 2013 Apr 15;6(2):114-125. doi: 10.70252/FLLL2291. eCollection 2013.
Weightlifters have commonly believed that changing joint position can alter specific muscle activation. The magnitude of force produced by a muscle is highly dependent upon the length of the muscle. The purpose of this study was to determine the effect of foot positioning on muscle activation of the superficial quadriceps as measured by surface electromyography (sEMG) during a functional squatting movement in healthy adults. Twenty physically active asymptomatic adults (7 females and 13 males) were included in the study while four different foot positions (Neutral, Internally Rotated, Externally Rotated, and Staggered) were assessed. Three quadriceps muscles (Rectus Femoris (RF), Vastus Medialis Oblique (VMO), and Vastus Lateralis Oblique(VLO) were measured. Raw EMG was transformed using a root mean square algorithm. Six one-way repeated measure ANOVAs were conducted to examine the peak and average RMS amplitude for each muscle across each condition, with an alpha level of 0.05 set a priori. Across all foot positions only the Staggered foot position reached statistical significance when compared to all other foot positions for each muscle group. Results suggest that altering the foot position during a partial weight squat has little to no effect on the EMG amplitudes of the quadriceps. However, more research is needed to examine the concentric and eccentric phases of the squatting motion separately with the addition of full weight bearing squats.
举重运动员普遍认为改变关节位置可以改变特定肌肉的激活情况。肌肉产生的力量大小高度依赖于肌肉的长度。本研究的目的是确定在健康成年人的功能性深蹲运动中，通过表面肌电图（sEMG）测量足部位置对股四头肌浅层肌肉激活的影响。本研究纳入了20名身体活跃的无症状成年人（7名女性和13名男性），同时评估了四种不同的足部位置（中立位、内旋位、外旋位和交错位）。测量了三块股四头肌（股直肌（RF）、股内侧斜肌（VMO）和股外侧斜肌（VLO））。原始肌电图使用均方根算法进行转换。进行了六项单因素重复测量方差分析，以检查每种情况下每块肌肉的峰值和平均均方根振幅，预先设定的α水平为0.05。在所有足部位置中，与每个肌肉组的所有其他足部位置相比，只有交错位足部位置达到了统计学显著性。结果表明，在部分重量深蹲过程中改变足部位置对股四头肌的肌电图振幅几乎没有影响。然而，需要更多的研究来分别研究深蹲运动的向心和离心阶段，并增加全负重深蹲。
