- 學位論文
前端弧形鞋底設計對於步態站立期間足底筋膜負載之影響
Effect of Anterior Rocker Sole Shoe Profiles on the Plantar Fascia Loading during Stance Phase of Gait
摘要
足底筋膜炎為足跟痛常見之主因，其成因眾多包含不正常足底結構或過度使用足部超出其負荷。以生物力學之觀點而言，此些因素皆可能造成足底筋膜過大之負載，而使得足底筋膜產生損傷。步態站立期間足底筋膜上負載明顯出現於平貼期至推進期之階段，尤其推進期時趾頭因受地板推擠而背屈，產生絞盤效應導致最大負載發生。弧形鞋為臨床上用於治療足底筋膜炎輔具之一，但鮮少針對輔具與足底筋膜負載的影響進行探討。因此本研究將結合步態實驗與動態有限元素分析，探討前端弧形鞋底外形對於步態站立期間足底筋膜負載之影響。 本研究建構一完整足部結構之三維六面體有限元素模型，包含足部骨頭、實體足底筋膜及其他軟組織，並建構全觸式鞋內墊及三種不同弧形角度之前端弧形鞋(10度、20度及30度)。利用步態實驗所獲得之運動學參數作為邊界條件，模擬步態站立期間穿著不同角度弧形鞋之足部運動，並依實驗所獲得的動力學參數進行結果驗證分析。足底軟組織材料參數，參照本研究室軟組織實驗結果套入模型進行分析。 本研究結果顯示足底筋膜張力由裸足組1338.2 N，RBS10°組1077.7 N，RBS20°組888.5 N，下降至 RBS30°組752.3 N。與跟骨連接處前端之足底筋膜von Mises應力峰值亦由裸足22.2 MPa，RBS10°組15.49 MPa，RBS20°組14.04 MPa下降至RBS30°組11.87 MPa。因此，穿著較大弧形角度之前端弧形鞋可抑制步態推進時足部結構之絞盤效應，降低足底筋膜所承受最大負載。本研究分析之結果，經地板反作用力及足底壓力結果之驗證，可提供臨床對於足底筋膜炎患者治療之方針及輔具製作師設計弧形鞋之參考。
並列摘要
Plantar fasciitis is commonly observed in the patients with heel pain. The etiology is multifactorial, such as abnormal foot structure or overuse injury. Both these factors may lead to excessive loading on the plantar fascia, and then impair it. It is obvious that the plantar fascia bears loading during the period of mid-stance phase and push-off phase. As to the push-off phase, the windlass effect is induced by dorsiflexion of the toes, and brings on the peak loading on the plantar fascia. In clinical practice, the anterior rocker sole is a common orthosis prescribed for the treatment of plantar fasciitis. The effect of orthoses to the loading of plantar fascia, however, is not well investigated. For this reason, the gait analysis and dynamic finite element analysis (FEA) were used in this study to investigate the effect of the anterior rocker shoe designs on the loading of planter fascia during the stance phase of gait. A three-dimensional finite element foot model, including the bones, the planter fascia and the other soft tissues, were reconstructed in this study. A total contact insole and the anterior rocker soles with 3 different designs of rocker angle were also created. The kinematic data obtained from the gait analysis was used as the boundary conditions to simulate the motion of the foot with different anterior rocker soles during the stance phase, while the kinetic data was used to validate the results from the FEA. The material property of the plantar soft tissues obtained from our previous study was adopted in this study as well. The result showed that the tensile loading of the planter fascia under barefoot, RBS10°, RBS20° and RBS30° conditions were 1338.2 N, 1077.7 N, 907.5 N and 752.3 N, respectively. The maximal peak von Mises stresses in the plantar fascia near the calcaneal tuberosity calculated 22.2 MPa, 15.49 MPa, 14.04 MPa and 11.87 MPa under barefoot, RBS10°, RBS20° and RBS30° conditions, respectively. As a result, wearing a shoe with larger anterior rocker angle would be able to inhibit the windlass effect, and the peak loading of the plantar fascia will thus be relieved. The validated results from this study can provide a treatment guideline for treatment of plantar fasciitis, and would be benefical to orthotis in the design of orthosis.