近年來，由於工業化的結果以及持續擴大的城鄉差距，青壯年多半離鄉工作，因此許多高齡者仍然在從事農耕的工作。然而一般農耕工具大多是單一的規格設計，並未考慮到不同使用者的身體條件差異或生理機能衰退程度；加上有許多工具幾乎沒有使用年限，農耕工作者由當初的青壯年持續使用工具至高齡階段，當初購買的農耕工具早已不符合他們的使用條件！因此本研究以農耕工具中的揹負式割草機為主，以觀察與訪談法探討高齡農耕工作者使用此工具的操作情況，由現有揹負式割草機使用調查結果可知高齡農耕工作者在操作揹負式割草機執行除草任務時多出現肩部，大腿外側，手部方面不適的情況；於是針對現有之揹負式割草機提出改良設計方案；最後透過使用性評估結果可知於揹負式割草機與人體接觸處，包含肩帶，腿靠，握把處加裝較厚的發泡材質有助於降低除草時帶來的震動，以減輕不適情況並提升使用者滿意度。

In recent years, most young adults are away from home countries to work in the city. Therefore, many elderly people still engage in farming work. However, the design of general farming facilities is usually standardized. It does not consider the variety of physical condition between users, and the degree of functional decline along time in a single user. Moreover, many tools don’t have limitation of service life, agricultural workers continually use those same tools from young to old; those tools which purchased years ago can’t meet the elder’s conditions of use already. Therefore, through observation and interview, this study focuses on a common farming tool-knapsack mower, in order to investigate how the elderly agricultural workers operate the tool. The survey revealed that the elderly agricultural workers often experienced discomfort over their shoulders, lateral thighs, and hands while they were using the knapsack mower for weeding. Thus we propose the improved design of the existing knapsack mower. According to the evaluation result, to install thickened foam materials over contact surface between human body and the knapsack mower, including the grip, the shoulder strap and the leg rely, reduces the shake during weeding, relieves users’ discomfort, and further improves elder workers’ satisfaction.