可輔助下樓梯之穿戴式裝置開發與評估

Abstract

上下樓梯是較困難的日常生活動作，相較於平地行走需要更多的身體適能來完成，易使高齡者處於危險且跌倒的風險中。上樓梯時重心向上移動，身體肌群可因為主動本體感覺而產生活化以因應跌倒的可能，但下樓梯時身體重心會有一下落的趨勢，產生跌倒的風險較高，因此下樓梯所需的輔助支撐相較於上樓梯多。現行幫助上下樓梯之輔助裝置多為裝設在樓梯間並利用馬達及軌道之樓梯升降椅，此類裝置較為笨重，在使用上較無法符合實際生活中的各種情況，而輕便穿戴式裝置中又少有針對下樓梯的輔助設計且現行多需要使用馬達電池導致使用時間受限，本研究開發一能夠幫助下樓梯之非動力穿戴式裝置，進而減少高齡者於下樓梯時之身體負擔。此機構參考下樓梯時人體膝關節活動並藉由文獻及人體計測資料計算所需之輔助，將輔具裝置穿戴在人體膝關節處，在下樓梯的過程中，輔具機構可以隨著膝關節彎曲而給予輔助力。本研究招募五位年輕(22 ~ 25 yrs.)與四位中年(50 ~ 64 yrs.)受試者驗證該輔助裝置之效果，使用自行建置之階梯實驗平台紀錄地面反作用力、動作時間及量測表面肌電訊號以評估穿戴輔助裝置前後之差異。結果顯示在下樓梯的過程中穿戴輔助裝置可以降低踩踏到階梯時之最大反作用力5 ~ 7 %；中年人股外側肌對股二頭肌之共同活化情形下降11 %，顯示出穿戴裝置可以提升關節穩定性，在協助支撐方面，可以降低中年人股外側肌之平均活化情形10 %，降低肌力需求。

The society in Taiwan is aged, and the life expectancy increases year by year. Studies have shown that the aging process would decrease the muscle strength of older people. Stair negotiation is hazardous for older people, and a portion of falling accidents were reported to occur on stairs especially while descending. By comparing level walking, stair negotiation is one of the daily demands and needs capable physical ability. Existing assistive devices for stair climbing, such as stair-lifting wheelchairs are either bulky or inconvenient to be applied in many environments. Other powered wearable assistive devices give assist while walking but not stair descending, and the weight and duration are restricted by motors and batteries. Therefore, the aim of this study is to develop a non-powered wearable device which can reduce the muscle demand on lower limbs for stair descending and to evaluate its efficacy. By considering the knee movement of stair descending and anthropometry data, we designed an assistive mechanism which can give support while knee flexion during descending. Four older adults (50 ~ 64 yrs.) and five younger adults (22 ~ 25 yrs.) were asked to perform stair negotiation to evaluate the efficacy of device. We collected the ground reaction forces and the electromyography of quadriceps and biceps simultaneously. Our results showed that the maximum ground reaction force reduced 5 ~ 7 % by wearing our device. Besides, older adults’ vastus lateralis vs biceps femoris Co-activation decreased 11 % that meant our device could increase the knee joint stability; the vastus lateralis mean muscle activity reduced 10 % during wearing device which indicated that our device could help to reduce muscle demand during single leg supporting.