貼紮對足跟墊回彈力不佳者足跟墊避震能力之影響

Abstract

足跟墊包含膠原纖維所構成的大小腔室儲存脂肪，具有吸震及減震的功能，以減輕足部在行走時所受到的衝擊。足跟墊如出現萎縮時，其避震能力會下降，因此產生發炎或疼痛。臨床上，以足跟墊貼紮產生限制效應來治療足跟墊疼痛者，過去研究發現療效極佳，且能增進其避震能力。然而有些人的足跟墊雖未造成疼痛症狀，但在受力後已呈現回彈力不佳的現象。對於足跟墊回彈力不佳者，目前尚無研究探討其避震能力，且尚不確定足跟墊貼紮是否能改變其避震能力。所以本研究旨在針對足跟墊回彈力不佳者施以足跟墊彈性貼紮，比較其避震能力在貼紮前後的差異，用以探討足跟墊貼紮的效應。此外，在主實驗進行前，先檢測站立重心轉移測試及足跟墊負載—卸載測試之測試者內信度。 本研究屬於便利抽樣、前瞻性研究、擬試驗分析、前後測研究的設計。收取20名足跟墊回彈力不佳者作為實驗組，並以性別、身高、體重及身體質量指數配對20名健康人當做控制組。每名受試者皆在有、無彈性貼紮狀況下接受站立重心轉移測試及足跟墊負載—卸載測試。貼紮順序採隨機方式，接受測試腳為慣用腳。在站立重心轉移測試中，受試者站立將重心以最快的速度從非慣用腳移到慣用腳，再移回非慣用腳，同時以超音波影像儀擷取足跟墊應變的資料，以荷重轉換器擷取足跟墊受力的資料，並分析足跟墊厚度、受壓指數、能量耗散率等參數。在足跟墊負載—卸載測試中，受試者採坐姿且膝關節伸直的姿勢，並利用步進馬達將超音波探頭以定速定距的方式對足跟墊進行負載及卸載的移動，同時擷取超音波彈性影像資料，再分析其巨腔室層與微腔室層的最大應變值。統計方法採用2×2複合式變異數分析，探討足跟墊回彈力不佳組與配對控制組在有無貼紮的差異，其顯著水準訂在在α=0.05，檢定力訂在0.8。此外，分別以8名健康人則進行站立重心轉移測試信度實驗及10名健康人進行足跟墊負載—卸載測試信度實驗，以檢測站立重心轉移測試與足跟墊負載—卸載測試之施測者內信度。統計方法為組內相關係數ICC3,5與量測標準誤。 結果顯示足跟墊彈性貼紮對於足跟墊回彈力不佳者，可以增加足跟墊厚度(16.2 ± 1.9mm vs. 18.3 ± 1.9 mm, p<0.05)及降低受壓指數(62.4 ±8.1% vs. 54.5 ± 10.5%, p<0.05)。但在能量耗散率方面，則僅對足跟墊回彈力輕度不佳者有降低的效應(68.3± 11.2 % vs. 62.1 ± 12.6%, p<0.05)，對足跟墊回彈力重度不佳的人則不會改變。以超音波彈性影像量測巨腔室層及微腔室層在壓縮或回彈時的最大應變值，發現貼紮前後並無顯著差異(p>0.05)。在健康人足跟貼紮後也有相類似的效果。若以足跟墊回彈力不佳者與健康人比較，足跟墊回彈力不佳者在足跟墊微腔室層壓縮時應變值較健康人來得大(16.0 ± 4.8% vs. 15.5 ± 3.6%, p<0.05)。至於站立重心轉移測試與足跟墊負載—卸載測試，本研究發現皆有良好的施測者內信度(ICC3,5=0.782-0.979)。 本研究針對足跟墊回彈力差者與健康人的足跟墊施以彈性貼紮，探討貼紮對其機械性質的影響，發現足跟墊彈性貼紮無法改變其組織本身的機械特性，但卻可藉由足跟墊厚度的增加來改變整個足跟墊的機械特性，以增進避震能力，此結果有助於臨床應用的實證參考。此外，本研究檢測站立重心轉移測試與足跟墊負載—卸載測試之再測信度，發現兩個測試皆有良好的施測者內信度，此結果有助於日後使用此二量測方法來檢測足跟墊機械特性。

The function of the heel pad is mainly composed of the adipocytes, separated by fibrous septa, whose function is to decrease and absorb the shock as the foot contacts on the ground during walking. If the heel pad becomes atrophy, its shock attenuation capacity decreased which may cause inflammation or pain of the heel pad. The heel pad taping had been reported to be effective in the treatment of heel pad pain syndrome through improving the shock attenuation capacity of the heel pad. However, some people present poor rebound capacity of the heel pad as compression loaded even though they do not have the heel pad pain. There were no evidences to identify the taping effect among them. The purpose of this research was to explore the confinement effect of the heel pad taping on shock attenuation capacity in individuals with poor-rebound heel pad. Prior to the main study, the intrarater reliability of the weight shifting test and loading-unloading test were all tested. This research was convenience sampling, prospective, experiment, and pretest/ posttest study design. Twenty individuals with poor-rebound heel pad and 20 matched controls participated in the main study. Each participant received both weight shifting test and the loading-unloading test under the taping and non-taping conditions. For the weight shifting test, the participants were asked to stand with fully weight bearing on the non-dominant leg, and then shift the weight to the dominant leg and back to the non-dominant leg as soon as possible. The strain and stress data were collected using ultrasonography and load cell synchronously. The mechanical properties variables, including thickness, compressibility index, and energy dissipation ratio of the heel pad were analyzed. For the loading-unloading test, the participants were asked to sit on the floor with knee fully extended. The ultrasound probe with a stepping motor driver compressed the heel pad in a fixed speed and fixed displacement and unload in the same way. The maximum strain at the macrochamber and microchamber layers were collected by elastography. The 2×2 ANOVA with mixed model was used to examine the differences between taping conditions and groups. The significant level was set at α=0.05, and the power was at 0.8. Another 8 and 10 healthy adults separately received 3-session weight shifting test and 2-session loading-unloading test to examine the intrarater reliability. The averaged data were used for statistical analyses, including ICC3,5 and SEM. The results revealed that the heel pad taping increased thickness (16.2 ± 1.9mm vs. 18.3 ± 1.9 mm, p<0.05) and decrease CI (62.4 ±8.1% vs. 54.5 ± 10.5%, p<0.05) of the heel pad for the participants with poor-rebound heel pad. EDR significantly decreased only in the participants with mild poor-rebound heel pad (68.3± 11.2 % vs. 62.1 ± 12.6%, p<0.05); however, it was not the case for those with severe poor-rebound heel pad. There was no significant difference in εcompression and εrecoil in both macrochamber and microchamber layers of the heel pad between taping conditions for both participants with poor-rebound heel pad and healthy adults. Higher εcompression of the microchamber layer in the participants with poor-rebound heel pad than in the healthy adults was found in this study (16.0 ± 4.8% vs. 15.5 ± 3.6%, p<0.05). Additionally, both the weight shifting and loading-unloading tests were highly reliable (ICC3,5=0.782-0.979). It was concluded that the confinement effect of the heel pad taping changed the mechanical properties of the heel pad through increase in thickness rather than alteration of the mechanical properties of the tissue itself for both participants with poor-rebound heel pad and healthy adults. This taping method may be helpful in the clinic. Since the weight shifting and loading-unloading tests were reliable, these tests were able to be used to measure the mechanical properties of the heel pad.