Nonisometric behavior of fascicles during isometric contractions of a human muscle
Nonisometric behavior of fascicles during isometric contractions of a human muscle
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DOI：
10.1152/jappl.1998.85.4.1230
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发表时间：
1998-10-01
影响因子：
3.3
通讯作者：
Fukunaga, T
中科院分区：
文献类型：
--
作者：
Ito, L;Kawakami, Y;Fukunaga, T
利用超音波量测活体人类胫骨前肌之肌束长度、羽状角及肌腱伸长。要求受试者（n = 9）在距解剖位置20度跖屈的踝关节角度处逐渐产生等长背屈扭矩，直至达到最大扭矩。肌束长度从90 +/- 7缩短至76 +/- 7（SE）mm，羽状角从10 +/- 1度增加至12 +/- 1度，肌腱伸长率增加至15 +/- 2 mm，分级力发展至最大。肌腱刚度随着肌腱力的增加而增加，从0-20 N时的10 N/mm增加到240-260 N时的32 N/mm。杨氏模量从0-20 N时的157 MPa增加到240-260 N时的530 MPa。可以得出结论，在人体肌肉的等长收缩中，机械功（其中一些被腱组织吸收）是由肌肉纤维的缩短产生的，并且超声可以用于确定人体肌腱的刚度和杨氏模量。
Fascicle length, pennation angle, and tendon elongation of the human tibialis anterior were measured in vivo by ultrasonography. Subjects (n = 9) were requested to develop isometric dorsiflexion torque gradually up to maximal at the ankle joint angle of 20 degrees plantarflexion from the anatomic position. Fascicle length shortened from 90 +/- 7 to 76 +/- 7 (SE) mm, pennation angle increased from 10 +/- 1 to 12 +/- 1 degrees, and tendon elongation increased up to 15 +/- 2 mm with graded force development up to maximum. The tendon stiffness increased with increasing tendon force from 10 N/mm at 0-20 N to 32 N/mm at 240-260 N. Young's modulus increased from 157 MPa at 0-20 N to 530 MPa at 240-260 N. It can be concluded that, in isometric contractions of a human muscle, mechanical work, some of which is absorbed by the tendinous tissue, is generated by the shortening of muscle fibers and that ultrasonography can be used to determine the stiffness and Young's modulus for human tendons.