藉由正常人之步態分析探討膝上截肢者使用義肢上樓梯之運動學輸入與輸出參數關係

Abstract

膝上截肢者至今仍無法使用義肢，如常人般以左右腳交替之方式完成上樓梯的動作，為使其未來能有更接近常人的上樓梯能力，本研究企圖藉由觀察常人上樓梯時的步態，分析矢狀面上主要之運動學輸入和輸出參數，包括軀幹前傾角度，髖關節與膝關節彎曲角度、踝關節背屈角度，以及人體質心的位移，進而探討此動作中，各階段輸入與輸出參數的對應關係。 實驗中使用之三維動作分析系統為Motion Analysis system，特製四階階梯，第二、三階下方放有AMTI測力板，受測者為正常男性，全身貼有Helen Hayes之皮膚標記，以自然姿態向上走，記錄其步態及測力板資料。實驗結果顯示，上樓梯時軀幹維持前傾，但角度變化不大，下肢各關節均有明顯的角度變化；人體質心以近於等速之水平分量向前移動，垂直分量則在步態週期中呈二階段向上移動。 本研究將上樓梯步態週期分為九個階段，以健側髖關節、膝關節、踝關節、質心向上位移，以及質心與健側施力點距離作為輸入參數，義肢膝關節、踝關節作為輸出參數，並找出其各轉折點之對應關係，或可於未來協助膝上截肢者使用義肢上樓梯運動策略之建立，進一步作為未來義肢之設計規範。

Above-knee amputees are unable to climb up stairs by prostheses step by step as normal people. This research attempts to observe the motion of normal people when walking up stairs and analyze the kinematic parameters in sagittal plane, including trunk forward tilt angle, hip and knee flexion angles, ankle dorsiflexion angle, and the displacement of center of mass (COM), so as to find the relationship between parameters. Kinematic data are collected using 3-D Motion Analysis system with Helen Hayes Marker Set. A normal male ascends a four-step custom-made stair where two AMTI force plates underneath to measure the foot reactions. The result shows that the trunk tilts forward with almost the same angle. All angles of lower limb joints have significant angular changes. The COM keeps moving upward but moves forward only in two periods during the gait cycle. The gait cycle is divided into nine stages which include two outputs, prosthetic knee and ankle, and five inputs, intact hip, knee, ankle, upward displacement of COM and distance between COM and center of pressure (COP) of intact foot. The relationship between inputs and outputs are thus found through comparison. This may help establish the moving strategy of above-knee amputees to ascend stairs by prostheses and provide design specifications of control of prostheses in the future.