Shear Wave Predictions of Achilles Tendon Loading during Human Walking
Shear Wave Predictions of Achilles Tendon Loading during Human Walking
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DOI：
10.1038/s41598-019-49063-7
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发表时间：
2019-09-17
影响因子：
4.6
通讯作者：
Thelen, Darryl G.
中科院分区：
文献类型：
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作者：
Keuler, Emily M.;Loegering, Isaac F.;Thelen, Darryl G.
在体内的肌肉肌腱负荷的评价是理解正常和病理人类行走的驱动的基础。然而，用于测量人体中的肌肉-肌腱负荷的常规技术对于步态分析的使用来说太侵入性。在这里，我们展示了使用剪切波传播的非侵入性措施作为行走过程中跟腱负荷的代理。12名健康青年在测力计上进行等长踝跖屈。测量跟腱波速、肌腱力臂、肌腱横截面积和踝关节扭矩。我们首先表明，肌腱应力和波速平方之间的线性关系可以从等距任务中校准。膝关节角度、踝关节角度或负荷率对受试者特定校准没有显著影响。校准的剪切波张力计被用来估计跟腱负荷时，步行速度范围从2米/秒。随着行走速度的增加，推离过程中的峰值肌腱应力从41 MPa增加到48 MPa，与逆动力学估计值相当。张力计还检测到跟腱负荷4至7 MPa的后期摆动。后期摆动肌腱负荷是不可辨别的逆动力学估计，但不符合被动拉伸腓肠肌肌腱单位。这项研究表明，使用校准的剪切波张力计，以评估肌腱负荷运动任务的能力。这种技术可以证明有利于识别作为特定对象运动模式基础的肌肉动作。
The evaluation of in vivo muscle-tendon loads is fundamental to understanding the actuation of normal and pathological human walking. However, conventional techniques for measuring muscle-tendon loads in the human body are too invasive for use in gait analysis. Here, we demonstrate the use of noninvasive measures of shear wave propagation as a proxy for Achilles tendon loading during walking. Twelve healthy young adults performed isometric ankle plantarflexion on a dynamometer. Achilles tendon wave speed, tendon moment arms, tendon cross-sectional area and ankle torque were measured. We first showed that the linear relationship between tendon stress and wave speed squared can be calibrated from isometric tasks. There was no significant effect of knee angle, ankle angle or loading rate on the subject-specific calibrations. Calibrated shear wave tensiometers were used to estimate Achilles tendon loading when walking at speeds ranging from ito 2 m/s. Peak tendon stresses during pushoff increased from 41 to 48 MPa as walking speed was increased, and were comparable to estimates from inverse dynamics. The tensiometers also detected Achilles tendon loading of 4 to 7 MPa in late swing. Late swing tendon loading was not discernible in the inverse dynamics estimates, but did coincide with passive stretch of the gastrocnemius muscle-tendon units. This study demonstrates the capacity to use calibrated shear wave tensiometers to evaluate tendon loading in locomotor tasks. Such technology could prove beneficial for identifying the muscle actions that underlie subject-specific movement patterns.