目的 扁平足在步態中會產生異常的足底壓力與影 響足部與膝關節的運動，極少研究探討其對腰椎 的影響。本研究調查足部類型和足弓支撐鞋墊對 步行中的下肢與腰椎關節運動學及足底壓力重心 位移的影響。 方法 三十九名成人應用足底壓力計量測兩腳足 弓，根據足弓指數（Arch Index, AI）及足部姿勢 指數（Foot Posture Index, FPI）區分成三組：正常 足、扁平足與雙足不對稱組。請參與者在七公尺長 的步道來回行走五回，在三公尺步道處踩過設置的 足壓板；在步行測試時同步記錄腰椎、膝關節活動 度。兩種足部穿著測試：一、運動鞋；二、前者鞋 內置足弓支撐鞋墊。 結果 扁平足組在足著地負荷期需較大膝關節活動度； 在著地中期產生較大足底壓力重心偏離角度，且在著 地中期及抬腳離地期足底重心位移的速度比其他兩組 慢。相較於扁平足組，雙足不對稱組使用較小的膝關 節活動度來執行步態推進期。當使用足弓支撐鞋墊 時，所有組別在著地中期及抬腳離地期呈現腰椎活動 度減少；但離地期增加膝關節活動度。扁平足在著地 期呈現減少膝關節屈曲，增加足底重心偏離角度。不 對稱組則是在著地中期降低膝關節活動度，在足部負荷期增加足底重心位移速度。

Purposes Flat feet result in abnormal plantar pressure during walking and affect the mobility of the feet and knee joint. However, few studies have examined the effects on the lumbar vertebrae. This study aimed to investigate the effects of the type of foot arch and foot orthosis on the kinematics and center of pressure (COP) progression in the lower limbs and lumbar vertebrae during walking. Methods A plantar-pressure measurement device was used to assess the foot arches in 39 adults, who were classified into three groups: normal feet, flat feet, and asymmetric feet, according to the arch index (AI) of the foot and the foot posture index (FPI). Participants were required to walk back and forth 5 times on a 7-meter-long trail and step on a foot plate at the 3-m marker. During the test, the mobility of the lumbar vertebrae and knee joint were recorded. Two types of footwear were tested: (1) sports shoes and (2) sports shoes with prefabricated orthoses. Results Subjects in the flat feet group required a larger range of motion (ROM) for the knee in the loading phase, applied a larger COP deviation angle in mid-stance, and had a slower COP progression velocity at the mid-stance and push-off phases in comparison to subjects in the other 2 groups. Compared with the flat feet group, the asymmetric feet group used smaller knee ROM to perform push-off. When orthoses were used, all groups had reduced lumbar ROM in mid-stance and the push-off phase, and increased knee ROM during pushoff. Subjects in the flat feet group had reduced knee flexion and increased COP deviation angle in the loading and mid-stance phases. Subjects in the asymmetric feet group had reduced knee ROM in mid-stance and increased COP velocity in the loading phase. Conclusions The kinematics and COP progression of the lumbar vertebrae and knee joint could be affected by different foot arch types and footwear. (Cheng Ching Medical Journal 2019; 15(2): 7-16)