部分足部截肢病人新式足部輔具之生物力學研究

Biomechanical studies of the newly designed foot prosthesis for patients with partial foot amputation

吳昱沁(Yu-Chin Wu)

指導教授 ： 陳文斌

中原大學/工學院/醫學工程研究所/碩士(2001年)

https://doi.org/10.6840/cycu200100472

摘要

截肢足的輔具製作在臨床上沒有一定的準則。截肢手術後因為足部結構的改變，造成患者步行時生物力學變化，導致其它功能上的代償，尤甚者二度截肢。電腦輔助設計和有限元素分析應用在足部和輔具，可以為臨床輔具設計和截肢足的生物力學探討節省龐大的實驗及製作開支，進而讓輔具的應用普遍化。
本研究探討的是臨床上截肢量最多的大拇趾截肢(hallux amputation)與蹠骨橫截肢(transmetatarsal amputation)兩種截肢群，利用電腦輔助工程設計軟體製作這兩種足部的全觸式鞋墊，未降低截肢造成的足底壓力負面影響，代入適當的鞋墊材質，並模擬步行狀態分析，以求更精確的分析結果。這部分的研究，是有限元素法應用在足部運動學的典型。
分析結果顯示，三種足部模型在穿著全觸式鞋墊之後，足底壓力普遍降低50%以上。裸足分析，截肢足各分區的足底壓略高於正常足的足底壓，穿著鞋具之後，三組模型的足底各分區壓力，除足跟區域外，都在100kPa之內，證實本研究中設計的全觸式鞋墊在材質與形狀上都確實達到減低足底壓的效果。有限元素分析用於足部生物力學研究，可得到實驗量測很難得到的骨骼內的應力應變分佈，本研究不僅可提供足底壓分析，也可提供骨骼在截肢後的應力應變變化，進而預估骨骼內最大應力值的發生位置。

關鍵字

應力應變 ； 足底壓 ； 截肢 ； 足部輔具 ； 有限元素分析

並列摘要

Foot structure changes following partial foot amputation surgery can result in abnormal biomechanical changes during gait. This may induce functional compensation, and subsequent re-amputation. Currently, there is no commonly accepted standardized partial foot prosthesis used in clinics. The aim of this research is to explore the biomechanics of partial amputation feet and to develop appropriate prostheses for such patients using CAD (Computer Aided Design) and CAE (Computer Aided Engineering) programs.
In this study, we investigated the two largest groups of foot amputation - hallux and transmetatarsal amputation (TMA) seen in clinics. Total contact prostheses for those two types of amputation were designed using CAD software and finite element models of the amputation feet and prostheses were generated. The stress distributions before and following the interventions of foot prostheses were quantified using finite element analyses. The effects of prosthesis on the plantar pressure and skeletal stress were investigated.
Results concluded that total contact prostheses could contribute 50% of the plantar pressure reduction. Peak plantar pressure was found to be higher in amputation feet than normal ones. Excluding M5 (plantar calcaneus) area, total contact prosthesis can reduce the peak pressure value to under 100kPa. This proves the valuable effect of plantar pressure reduction by the special geometry and material selection of the total contact prostheses. Finite element analysis has the advantage of quantifying the skeletal stress distributions that cannot be measured from experiments. This study can be a reference on the plantar pressure and skeletal stress distributions in foot amputation and prosthesis design.

並列關鍵字

Plantar pressure ； Foot ； Prosthesis ； Partial foot amputation ； Finite element analysis

參考文獻

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