客製化鞋墊對於功能性扁平足患者的生物力學與疼痛之療效

Abstract

背景：客製化鞋墊能針對功能性扁平足進行介入與矯正，過去已有使用三維列印技術製作鞋墊的文獻，然而使用的技術類型、材料與結構設計不一，使其在療效方面相比傳統製程或是減法製程尚無法定論。 實驗目的：使用電腦輔助設計配合三維列印製程製作客製化鞋墊，建立臨床驗證流程，比較不同熱塑性聚合物的鞋墊於功能性扁平足受試者穿戴後的足部功能與生物力學參數變化。 方法：本計畫收入10位功能性扁平足患者（足部姿勢指數大於六分）進行三種鞋墊的穿戴，分別採用三維列印（尼龍與熱塑性聚氨酯材質）與電腦銑床製作（乙烯醋酸乙烯酯共聚物材質）。實驗利用足底壓力感測器與量表紀錄介入後的生物力學參數、疼痛與個別一週穿戴後的足部療效。統計則採用弗理曼二因子等級變異數分析與事後分析來比較組間差異。 結果：尼龍材質的三維列印鞋墊能降低第一蹠骨的最大足底壓力與力量，行走時能將身體重心帶往外側偏移，也擁有最好的舒適度並降低其疼痛程度。熱塑性聚氨酯材質的三維列印鞋墊能增加內側中足的最大足底壓力、力量與接觸面積，重新分配重量以降低足部疼痛。此外，三維列印鞋墊都能降低單腳時的重心偏移速度，然而彼此之間卻沒有顯著差異。個別穿戴一週後，所有鞋墊的足部功能量表分數都會顯著下降，然而熱塑性聚氨酯材質的鞋墊相較乙烯醋酸乙烯酯共聚物材質的鞋墊其分數會相對上升。 結論：三維列印提供精準的客製化鞋墊製程，尼龍與熱塑性聚氨酯三維列印鞋墊能有效改善功能性扁平足患者的足部生物力學表現、疼痛與功能，可作為客製化鞋墊的新選擇。

Background: Functional flatfoot can be treated with customized insoles. There have been few studies using 3D printing for customized insoles for functional flatfoot. Besides, compared to the traditional methods and subtractive manufacturing, the effect of 3D printing insoles is still controversial and depends on technology, materials and design. Purpose: This study aims to compare the effects of 3D printing customized insoles using different thermoplastic materials on functional flatfoot patients’ foot function and biomechanics. Method: Ten patients with functional flatfoot (foot function index > 6) were recruited in this study and wore three kinds of customized insoles fabricated by 3D printing with Nylon (3D-Nylon) and TPU (3D-TPU) or computer numerical control machine with EVA (CNC-EVA). F-Scan system and questionnaires were used to record foot biomechanics and pain after wearing insoles immediately, and foot conditions each week. Statistical analysis was adopted for the Friedman test and post-hoc test for all outcome measures to test the difference between groups. Result: 3D-Nylon insole significantly decreased peak pressure and peak force in 1st metatarsal, shifted the center of pressure (COP) laterally, and alleviated pain during walking. 3D-TPU insole increased peak pressure, peak force and contact area in the medial midfoot, which reduced pain during walking. During single leg stance, COP excursion velocity was decreased with all insoles when compared with shoe alone condition. However, there was no significant difference between groups. Foot function index (FFI) was decreased with all insoles when compared with shoe alone condition. Besides, FFI was significantly higher with 3D-TPU insole than CNC-EVA insole. Conclusion: 3D printing provides a precise fabrication process of customized insoles. 3D-Nylon and 3D-TPU insoles can effectively improve the biomechanical performance, pain and function of the foot of patients with functional flatfoot, and can be used as a new choice for customized insoles.