University of British Columbia Okanagan, 3333 University Way, Kelowna, BC, V1V 1V7, Canada.
Eur J Appl Physiol. 2010 Dec;110(6):1251-7. doi: 10.1007/s00421-010-1600-x. Epub 2010 Aug 25.
The purpose of this study was to examine force steadiness in three positions of the forearm in young men and women across a variety of force levels. Eight young men and eight young women performed three maximum voluntary contractions (MVCs) in the neutral, supinated, and pronated forearm positions. Viewing a target line on a computer screen, subjects performed submaximal isometric contractions relative to their own MVC at 2.5, 5, 10, 25, 50, and 75% in each of the three forearm positions. Force steadiness was determined as the coefficient of variation (standard deviation around the mean force). A repeated-measures three-way ANOVA was used to assess the differences in force steadiness between sex, position, and force level. Men were stronger than women in all three forearm positions. Overall, men were steadier than women across all force levels and forearm positions. The neutral and supinated positions were equally strong and steady, and the pronated position was the weakest and least steady position. The forearm was most steady between 25 and 75% MVC, and least steady at the lower force levels. When correlations were run between MVC and coefficient of variation at all force levels and all forearm positions, a strong negative relationship was found (r = -0.49). In conclusion, men were stronger, as well as steadier, than women. The neutral and supinated forearm positions were both stronger and steadier than the pronated position. Results suggest that one of the primary factors influencing sex differences in force steadiness is absolute strength.
本研究旨在探讨男性和女性在前臂三个位置的力稳定性，涵盖了多种力水平。8 名年轻男性和 8 名年轻女性在前臂中立位、旋后位和旋前位分别进行了三次最大自主收缩（MVC）。受试者通过电脑屏幕上的目标线，在三个前臂位置的 2.5%、5%、10%、25%、50%和 75%的自身 MVC 相对应的亚最大等长收缩。力稳定性由变异系数（平均值周围的标准偏差）确定。采用重复测量三因素方差分析评估性别、位置和力水平对力稳定性的差异。男性在前臂三个位置的力量均强于女性。总体而言，男性在所有力水平和前臂位置的力稳定性均强于女性。中立位和旋后位的力量和稳定性相当，旋前位的力量和稳定性最差。在 25%至 75%的 MVC 之间，前臂最稳定，在较低的力水平下最不稳定。当在所有力水平和所有前臂位置下将 MVC 与变异系数进行相关性分析时，发现两者之间存在很强的负相关关系（r=-0.49）。总之，男性的力量和稳定性均强于女性。中立位和旋后位的力量和稳定性均强于旋前位。结果表明，影响力稳定性性别差异的主要因素之一是绝对力量。
