嚴重痙攣中風患者之張力降低踝足矯具之設計與效應

本研究目的為使用低溫塑材為下肢嚴重痙攣中風患者設計一張力降低(Reducing tone of Inversion and Drop foot, RID)踝足矯具，並與前葉式踝足矯具(anterior ankle foot orthosis, AAFO)比較，以檢視新式RID踝足矯具之靜態站立平衡及步態效應。我們設計RID踝足矯具依據三點壓力系統、踝足矯具可能降低張力的特點、國際義肢與矯具協會共識會議“最佳做法(best practice)”的建議、痙攣抑制及足印壓力分布的技術及藉由踝關節背屈增加膝關節屈曲力距等。以平衡儀(Smart Balance Master System)的感覺組合測驗(Sensory Organization Test)計算壓力中心的移動變化及三維動作資料擷取系統進行步態分析。使用Wilcoxon符號等級檢定比較15位受試者穿戴兩種踝足矯具之差異。RID踝足矯具較傳統前葉式踝足矯具增加考慮跟骨的負荷、維持距下關節及跟骨的生理結構位置與第一蹠骨處的減壓包覆。效應研究結果顯示，穿戴RID踝足矯具與前葉式踝足矯具，在壓力中心改變的相關數據與步態參數，沒有顯著差異。穿戴RID與前葉式踝足矯具，在站立中期的對稱性(患側膝關節與健側膝關節屈曲角度的差異)有顯著差異(P = 0.013)，穿戴RID雙側膝關節屈曲差異較小。穿戴兩種踝足矯具分別與正常老年人數據比較，穿戴RID踝足矯具於站立中期的踝關節外翻角度(3.53°)與正常老年人(5.4°)較接近(P > 0.05)。穿戴RID踝足矯具站立期與擺動期的時間比例(70.1%：29.9%)與正常老年人 (62.3%：37.7%)較接近(P > 0.05)。RID踝足矯具對靜態站立平衡及基本步態與傳統前葉式踝足矯具有相似的效益，而站立中期雙側膝關節對稱與踝關節外翻角度及站立期與擺動期的時間比率有更佳的效益。

The purposes of this study were (1) to design a low temperature thermoplastic ankle foot orthosis (AFO) to reduce tone of inversion and drop foot (RID) for stroke patients with severe spastic lower limb and (2) to investigate the effects of the RID AFO on static standing balance and gait by comparing with anterior AFO.Design of the RID AFO was based on three-point pressure system, potential tone reduction features, “best practice” suggestion of the International Society for Prosthetics and Orthotics (ISPO), spasticity inhibition and foot pressure distribution techniques, and increasing knee flexion moment via ankle dorsiflexion. The Sensory Organization Test of the Smart Balance Master System was used to quantify center of pressure (COP) sway and the three-dimensional motion capture system was used for gait analysis. Statistical comparison between RID and anterior AFO was done with the Wilcoxon signed-rank test in 15 subjects.The RID AFO was more concerned with heel loading, aligning the subtalar joint and calcaneus in its neutral position and providing cover and elevation beneath the metatarsal heads to reduce excessive tone in plantarflexion and inversion. The results of effects study showed that there were no significantly differences in COP sway parameters and gait parameters between two AFOs. There was a significant difference (P = 0.013) in mid stance symmetry by calculating the difference in knee flexion between the affected and sound limb. The difference in knee flexion was smaller when wearing the RID AFO. Comparing with the data of normal older adults, with the RID AFO, the ankle eversion angle (median = 3.53°) in mid stance was similar to that (5.4°) in normal older adults (P > 0.05) and the stance/swing ratio (median = 70.1%: 29.9%) was similar to that (62.3%: 37.7%) in normal older adults (P > 0.05).No difference was found in the effects on static standing balance and gait parameter between the RID AFO and AAFO. There were more beneficial results on knee flexion symmetry as well as ankle eversion in mid stance, and stance/swing ratio when wearing the RID AFO.