Brown Stephen H M, McGill Stuart M
Department of Kinesiology, University of Waterloo, 200 University Avenue West, Waterloo, Ontario, Canada.
Clin Biomech (Bristol). 2010 Feb;25(2):115-23. doi: 10.1016/j.clinbiomech.2009.10.001. Epub 2009 Oct 30.
Ultrasound imaging is a valuable tool which, when applied appropriately, has the potential to provide information regarding the mechanics of abdominal muscle contraction. Typically, changes in muscle thickness are obtained and interpreted. However, the link between ultrasound measures of muscle thickening and EMG measures of activation is not clear.
Five healthy males performed a series of abdominal muscle contractions while surface EMG and trunk posture were monitored and ultrasound images of the internal oblique and external oblique were captured both at relaxation and upon contraction. Ramped isometric flexor and extensor moment contractions were also assessed and compared between EMG and ultrasound.
No definitive relationship between increases in muscle activation and corresponding measures of thickening was observed. Correlations between the two measures, across all contraction types, were 0.14 for internal oblique and -0.22 for external oblique.
The lack of clear association between abdominal muscle activation and thickening may be due to the composite laminate-like structure of the abdominal wall, with force being transmitted between obliquely oriented muscle layers. Thus, ultrasound alone may not be a valid measure of muscle activation or force in the unique architecture of the abdominal wall.
超声成像技术是一种有价值的工具,若应用得当,它有可能提供有关腹部肌肉收缩力学的信息。通常,会获取并解读肌肉厚度的变化。然而,肌肉增厚的超声测量与激活的肌电图测量之间的联系尚不清楚。
五名健康男性进行了一系列腹部肌肉收缩动作,同时监测表面肌电图和躯干姿势,并在放松状态和收缩时采集腹内斜肌和腹外斜肌的超声图像。还评估了渐增的等长屈肌和伸肌力矩收缩,并在肌电图和超声之间进行比较。
未观察到肌肉激活增加与相应增厚测量之间存在明确关系。在所有收缩类型中,两种测量方法之间的相关性,腹内斜肌为0.14,腹外斜肌为 -0.22。
腹部肌肉激活与增厚之间缺乏明确关联,可能是由于腹壁的复合层状结构,力在倾斜排列的肌肉层之间传递。因此,仅靠超声可能无法有效测量腹壁独特结构中的肌肉激活或力量。