足部的發展及其生物力學與生理學之效應

本前瞻性研究的主要目的是探討學童足部的成長及扁平足的定義和發生率，形成扁平足相關因素，如身體質量指數、性別、年齡、地區，及生理功能的表現，如跳遠或跑步能力。足部特殊角度與尿失禁的相關性都在研究中。並進一步進行體內及體外之負重實驗，以探討負重對韌帶或肌腱的影響。　　內側縱弓一直是被認為定義扁平足的主要參考，而足印是足型的評估最常用的工具。所以本研究利用EMED ST-4電容系統的壓力板來測量足底面積、壓力、及足型。足底的形狀是在最大壓力時所馭得，足型及足部的角度則用Novel-Ortho軟體分析，以探討它們與內側縱弓的關係。除了比較足部參數與性別、身高及體重的關係外，並由放射線照片的測量以定義扁平足，同時分析學童扁平足在肥胖、性別、地區與體適能的相關性。另外，利用可調整的踝關節站立架以改變骨盆傾斜的角度，及用陰道探測器測量體盆底肌內收縮時的壓力。再利用分子生物學的方法，測量不同負重對肌腱細胞基因的表現，及沒有負重下，韌帶纖維的組織變化。　　結果顯示足型在男女呈雙型式之分佈，女孩的腳長、腳寬、足跟寬皆比較小，而男孩的足弓下角、足部前進角度、內跗骨角及前蹠角反而比較大。另外足弓下角和放射線照片的跗骨－第一蹠骨角有顯著的相關性，所以利用放射線照片的測量結果，定義足弓下角大於或等於153.5度為扁平足，進而發現足長、足寬、足跟角及足部壓力指數在非扁平足族群比較大，然而，拇趾角、足部前進角度及前蹠角在扁平族群比較大。研究中也顯示身體質量大於95個百分比者，是15~84個百分比者的3.58 倍，男生有扁平足的盛行率是女生的2.42倍，都市學童的盛行率是鄉村學童的4.2倍。另外，扁平足學童的跳遠及跑步能力也比非扁平足學童差。扁平足的人，其足踝背曲範圍較小，有可能日後較易有婦女尿失禁的現象。體外實驗顯示出，4.5%機械負重可有效促進後脛肌肌腱細胞的基因表現，而人體試驗也顯示出，沒有負重會造成韌帶惡化。　　傳統的墨水印雖方便又便宜，然而電容式足印卻容易操作，且可以克服傳統墨水印耗人力的缺點，本研究是第一個以電容壓力板來大量評估學童的動態足印，所得之資料可以探討學童足部的成長的重要變化。足部參數亦可提供扁平足學童製作輔具的參考。研究結果也指出，減重及輔具應可增加學童體適能。而足底肌肉運動及少穿鞋子亦可降低扁平足的發生，同時可能降低婦女尿失禁。由研究的結果得知，機械性的負重會影響肌腱的表現，所以適當的機械性負重會促進纖微母細胞基因的表現，但太多或沒有負重，卻有相反效果，因此，吾人正研究利用機械性負重的新穎模式來治療扁平足的併發症。

關鍵字

足部發展；扁平足；足部生物力學；足部生理學；機械負重

並列摘要

The purpose of this prospective study was to investigate the foot evolution in children, flatfoot definition and flatfoot incidence. The factors , such as body mass index, gender, age, district, were studied. Running and jumping performance and the clinical effects on flatfoot children were analyzed. The relationship between ankle positions and women with stress urine incontinence was also investigated. Furthermore, the effects of mechanical load on tendons or ligaments were studied. The assessment of foot morphology by using footprints is common. Medial longitudinal arch (MLA) has been used as a main reference to diagnose flatfoot. To measure foot types, contact area, pressure, and force variables, we used an EMED ST-4 capacitance mat transducer. These parameters with maximum pressure diagrams were analyzed by using Novel-Ortho software (version 0.87). The relationships between foot parameters and gender, body height or body weight were investigated. Flatfoot definition could be done by analyzing footprints. Therefore, we studied the flatfoot prevalence related to BMI, gender, places and physical activities. To assess pelvic floor muscle (PMF) activity in women with stress urinary incontinence, an adjustable ankle platform was used. PMF activity was measured with an intravaginal probe. In the force study, fibroblast showed gene expression under different mechanical loading by using Flexcell○R Tension Plus TM System. The changes of fiber morphology in stress deprived were measured. The results showed that sexual dimorphism in foot parameters. Girls had smaller foot length, width and heel width and boys had larger subarch angle, foot progressive angle, medial tarsal angle and anterior plantar angle. Subarch angle indicated well correlated to medial longitudinal arch and was used to define the flatfoot. When the degrees of the subarch angle were greater than 153.5°, a flatfoot was defined. From the results, foot length and width, heel angle and pressure indices were larger in non-flatfoot children. However, hallux angle, progressive angle and anterior plantar angle were larger in flatfoot groups. Higher flatfoot prevalence was also presented in obese children. Children with BMI greater than 95 percentile showed 3.58 times more than those with BMI between 15~85 percentile. Flatfoot prevalence in boys was 2.42 times than that in girls. The prevalence in urban students was 4.2 times than that in rural students. Obese or flatfoot students showed poorer physical fitness. Women with flatfeet might have the tendency of urine stress incontinence in this study. Furthermore, mechanical loading could promote fibroblast gene expression in vitro and human ligaments with stress deprived deteriorated into poor morphologies. The traditional method of acquiring ink footprint is a simple method measurement, but time-consuming, laborious and messy. Capacitance footprint is an easier way to overcome the disadvantages of obtaining ink footprints. In this study, foot data are useful for feet functional assessment and foot parameters can be applied in orthotic manipulation for flat feet in children. Reduced body weight and suitable orthoses to correct their flat feet may increase their jumping and running abilities. On the other hand, intrinsic muscle training in foot plantar area and reduced duration of footwear would get great benefit to reduce the flatfoot incidence in children. Women with flatfoot may have higher stress urine incontinence. From this study, we also assume that suitable mechanical loading might have promoted tendon or ligament function; however, overload or unload presented negative effects. Novel treatments with mechanical load are expected for the flatfoot children in the future.

並列關鍵字

foot development ； flatfoot ； foot biomechanism ； foot physiology ； mechanical load

參考文獻

第一章: 參考文獻

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