足底筋膜為支撐足弓之重要結構，在我們日常生活的活動中會承受很大的張力，若是筋膜受到的負載超過其所能承受，造成發炎的現象，是為足底筋膜炎。目前認為造成足底筋膜炎之原因可能有很多，不過力學上的負荷過度被認為是最直接原因。所以本研究之目的在探討足底筋膜於步態著地期之力學行為。
本研究以電腦斷層掃描影像為基礎，利用逆向工程技術重建一完整之足部三維有限元素模型，包含骨頭、軟骨、韌帶、足底筋膜和其他軟組織。在邊界條件設定方面，在小腿遠端給予位移同時在足跟處給一阿基里斯腱的拉力，重建足部步態之過程，來探討整個過程中足底筋膜之受力狀態。
結果顯示足底筋膜之受力在擺盪前期一開始達到最高點，約為體重的0.7倍。在足底筋膜在靠近跟骨處有明顯之應力集中現象，步態後期之等效應力最大值為前期之2.3倍。絞盤機制的作用可以使筋膜的張力增加66%。
本研究藉由使用薄膜元素來建構韌帶組織，使足部的模擬更加真實。同時，在脛骨遠端給予位移和在足跟處給予阿基里斯腱之拉力，可以模擬出整個步態著地期之過程。

Plantar fascia is one of the major arch supporters of foot, it sustains high tension during daily activities. When the loading on the plantar fascia over the tissue’s ability, the plantar fascia is subject to inflammatory reaction called plantar fasciitis. The causes of plantar fasciitis are multifactorial, however mechanical overload has been cited as the major factor. The purpose of this study was to investigate the biomechanical responses of plantar fascia during the whole stance phase.
A 3-D finite element foot model containing bones, cartilages, ligaments, plantar fascia as well as other soft tissues was constructed. The movements of the foot during stance phase were reproduced by prescribing the kinematics of the proximal part of the tibia. Moreover the Achilles tendon force was applied on calcaneus bone.
The result shows that the peak tension of plantar fascia was at late stance about 0.7 body weight. A stress concentration occurred near the medial calcaneal tubercle. The fascia peak von Mises stress could be increased by 2.3 times when comparing between late stance and mid-stance. The fascia tension could increase by 66% due to windlass mechanism.
With the membrane element used in the ligament tissue, this finite element model simulates the foot mechanical structure more accurately. By prescribing the kinematic data of distal tibia during stance phase, current model could reveal the fascia tension during the whole stance phase.

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