摘要

In this study, the effects of various pennation models on predictions of total fiber force and fiber length were compared. Four different pennation models were assumed, and musculotendon dynamics was performed with each pennation model for two different simulations: (1) isokinetic contraction at angular velocities of 1, 50, 100, and 500A degrees/s with fully-activated tibialis anterior (TA) muscle; and (2) isometric contraction at -30A degrees, -15A degrees, 0A degrees, and 15A degrees with altered TA muscle activation. Total fiber force and fiber length obtained from each model were compared. Results from the isokinetic simulation showed that errors in the peak normalized fiber force were approximately +/- 1%, and the operating range of the normalized fiber length was the narrowest in the realistic model. Pennation angles from the realistic model showed a considerable variation compared with the variable model in isometric simulation; moreover, the realistic model predicted the largest forces and the narrowest operating range of the normalized fiber length. From this study, the variable pennation model was good for the condition of fixed muscle activation, but rather underestimated the force when the muscle activation varied. In addition, it was confirmed that the changes in pennation angle mainly result in the operating range of the fiber length.

  • 出版日期2015-6

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