Lin Chih-Chieh, Chang Chih-Han, Wu Chu-Lung, Chung Kao-Chi, Liao I-Chen
Institute of Biomedical Engineering, National Cheng Kung University, 1, University Road, Tainan 701, Taiwan.
Med Eng Phys. 2004 Jan;26(1):1-9. doi: 10.1016/s1350-4533(03)00127-9.
The socket liner plays a crucial role in redistribution of the interface stresses between the stump and the socket, so that the peak interface stress could be reduced. However, how the peak stress is affected by various liner stiffnesses is still unknown, especially when the phenomenon of the stump slide within the socket is considered. This study employed nonlinear contact finite element analyses to study the biomechanical reaction of the stump sliding with particular attention to the liner stiffness effects of the trans-tibial prosthesis. To validate the finite element outcomes, experimental measurements of the interface stresses and sliding distance were further executed. The results showed that the biomechanical response of the stump sliding are highly nonlinear. With a less stiff liner, the slide distance of the stump would increase with a larger contact area. However, this increase in the contact area would not ensure a reduction in the peak interface stress and this is due to the combined effects of the non-uniform shape of the socket and the various sliding distances generated by the different liner stiffnesses.
承窝衬垫在残肢与承窝之间的界面应力重新分布中起着关键作用，从而可以降低峰值界面应力。然而，峰值应力如何受到各种衬垫刚度的影响仍然未知，尤其是当考虑残肢在承窝内滑动的现象时。本研究采用非线性接触有限元分析来研究残肢滑动的生物力学反应，特别关注经胫假肢的衬垫刚度效应。为了验证有限元结果，进一步进行了界面应力和滑动距离的实验测量。结果表明，残肢滑动的生物力学响应是高度非线性的。使用较软的衬垫时，残肢的滑动距离会随着接触面积的增大而增加。然而，接触面积的这种增加并不能确保峰值界面应力的降低，这是由于承窝形状不均匀以及不同衬垫刚度产生的各种滑动距离的综合影响。
