Lee Ju-Eun, Park Ga-Hyeon, Lee Yun-Seop, Kim Myoung-Kwon
Department of Physical Therapy, Youngsan University.
J Phys Ther Sci. 2013 Sep;25(9):1059-61. doi: 10.1589/jpts.25.1059. Epub 2013 Oct 20.
[Purpose] This study examined the differences in muscle activation between flat and normal feet in the one-leg standing position which delivers the greatest load to the lower extremity. [Subjects] This study was conducted with 23 adults, 12 with normal feet and 12 with flat feet, with ages ranging from 21 to 30 years old, who had no neurological history or gait problems. [Methods] The leg used for one leg standing was the dominant leg of the subjects. The experimenter instructed the subjects to raise the non-dominant leg with their eyes open, and the subjects maintained a posture with the non-dominant leg's knee flexed at 90° and the hip joint flexed at 45° for six seconds. In the position of one-leg standing, a horizontal rod was set at the height of the waist line of the subjects who lightly placed two fingers of each hand on the rod to prevent inclination of the trunk to one side. Measurements were taken three times and the maximum value was used. A surface electromyogram (TeleMyo 2400T, Noraxon Co., USA) was used to measure muscle activities. [Results] We compared muscle activities between flat and normal foot, and the results show a significant difference between normal and flat feet in the muscle activity of the abductor hallucis muscle. [Conclusion] The subjects with flat feet had relatively lower activation of the abductor hallucis muscle than those with normal feet during one leg standing. We infer from this that the abductor hallucis muscle of flat foot doesn't work as well as a dynamic stabilizer, compared to a normal foot, during one leg standing.
[目的] 本研究探讨在单腿站立位时扁平足与正常足之间的肌肉激活差异，单腿站立位会给下肢带来最大负荷。[对象] 本研究对23名成年人进行，其中12名正常足，12名扁平足，年龄在21至30岁之间，无神经病史或步态问题。[方法] 用于单腿站立的腿为受试者的优势腿。实验者指示受试者睁眼抬起非优势腿，受试者保持非优势腿膝关节屈曲90°、髋关节屈曲45°的姿势6秒。在单腿站立位时，在受试者腰线高度设置一根水平杆，受试者双手各用两根手指轻轻搭在杆上以防止躯干向一侧倾斜。测量进行三次，取最大值。使用表面肌电图（TeleMyo 2400T，美国Noraxon公司）测量肌肉活动。[结果] 我们比较了扁平足与正常足之间的肌肉活动，结果显示拇展肌的肌肉活动在正常足与扁平足之间存在显著差异。[结论] 在单腿站立时，扁平足受试者拇展肌的激活程度相对低于正常足受试者。由此我们推断，在单腿站立时，与正常足相比，扁平足的拇展肌作为动态稳定器的作用欠佳。
