Manal Kurt, Roberts Dustyn P, Buchanan Thomas S
Center for Biomedical Engineering Research, Department of Mechanical Engineering, University of Delaware, Newark, DE 19716, USA.
J Biomech. 2008 Aug 7;41(11):2492-7. doi: 10.1016/j.jbiomech.2008.05.005. Epub 2008 Jun 24.
Ultrasonography was used to measure pennation angle and electromyography (EMG) to record muscle activity of the human tibialis anterior (TA), lateral gastrocnemius (LG), medial gastrocnemius (MG), and soleus (SOL) muscles during graded isometric ankle plantar and dorsiflexion contractions done on a Biodex dynamometer. Data from 8 male and 8 female subjects were collected in increments of approximately 25% of maximum voluntary contraction (MVC) ranging from rest to MVC. A significant positive linear relationship (p<0.05) between normalized EMG and pennation angle for all muscles was observed when subject specific pennation angles at rest and MVC were included in the analysis. These were included to account for gender differences and inter-subject variability in pennation angle. The coefficient of determination, R(2), ranged between 0.76 for the TA and 0.87 for the SOL. The EMG-pennation angle relationships have ramifications for use in EMG-driven models of muscle force. The regression equations can be used to characterize fiber pennation angle more accurately and to determine how it changes with contraction intensity, thus providing improved estimates of muscle force when using musculoskeletal models.
在Biodex测力计上进行分级等长踝关节跖屈和背屈收缩时，使用超声检查测量羽状角，并使用肌电图（EMG）记录人体胫骨前肌（TA）、外侧腓肠肌（LG）、内侧腓肠肌（MG）和比目鱼肌（SOL）的肌肉活动。收集了8名男性和8名女性受试者的数据，以最大自主收缩（MVC）的约25%为增量，范围从静息到MVC。当分析中纳入静息和MVC时受试者特定的羽状角，观察到所有肌肉的归一化EMG与羽状角之间存在显著的正线性关系（p<0.05）。纳入这些是为了考虑性别差异和羽状角的个体间变异性。决定系数R²在TA为0.76和SOL为0.87之间。EMG-羽状角关系对用于肌肉力量的EMG驱动模型有影响。回归方程可用于更准确地表征纤维羽状角，并确定其随收缩强度的变化，从而在使用肌肉骨骼模型时提供对肌肉力量的改进估计。
