近年來台灣地區隨著經濟發達及醫療公共衛生進步，工業生產面臨人口少子化、勞動人力老年化的衝擊，面對勞動人口老化現象已成為重要的社會經濟議題。職業性肌肉骨骼傷害近年來在我國勞工保險職業病給付中所占的比率甚高，於職業病之議題上頗受重視。此疾病源自勞工因長期執行重複性動作、過度施力及工作姿勢不當，而導致局部的慢性傷害甚至發生下背痛與椎間盤突出等職業病。使得中高齡勞工體能對工作內容與工作環境的適應力減弱。本文的目的是以人因關鍵指標分析方法（Key Indicator Method）分析勞工作業方式，以改善台灣金屬工業中高年齡勞工之工作場所，並協助一家工廠於現場作業環境的工作條件和設施進行研究和改進。研究分析之結果發現，許多台灣金屬中高年工作者大多為男性勞工作業於高風險人因的工作環境，因此迫切需要改善工作環境，以防止任何肌肉骨骼傷害職業傷害的發生。

Purpose The purpose of this paper is to analyze and enhance the work improvement program in Taiwan’s Metal Industry. Two plants’ work conditions and facilities were investigated and improved. It was found that many of the workers are middle-aged men who occupy high risk jobs. Therefore, there is a strong need to improve the work environment to prevent the occurrence of occupational injuries. Method Key Indicator Method (KIM) is a consistent method used to assess risk involvement in manual material loading. It is conducted by quantifying the key indicators individually (time, load, posture and working conditions using rating points) and calculating the risk score and risk range. At Plant 1, observed areas were coil coating, coil packaging, and chemical storage area. The areas observed in Plant 2 were iron cutting, iron scrap, H-type iron conveyor operation, and iron burr trimming area. According to KIM, coil coating area time rating point was 6 before improvement, since lifting/positioning occurs fewer than 500 times per day. The load rating point was 2, since the load was less than 20 kg. The posture rating was 4, since the torso is bent slightly and there is high load on the shoulder. The working condition rating point score was 0, since the working condition is good. Therefore, the risk score is 36, the load status is ＂increased＂, and the risk range is 3. Based on the observational results, an improvement plan was designed and implemented to fit the middle-aged workers in the facilities. The rating points were re-assessed afterwards to examine the improvement effectiveness. Results & Discussion The work facilities designed and implemented at Plant 1 are: an additional rotating arm bracket for the coil coating area; height adjustments for pallets, to 80 cm; height adjustment for sleepers’ bottom, to 50 cm; adjustable seat hights and movable brackets for the coil packaging area; and, a lift cart and stairs for the chemical area. All the equipment was designed with a limited budget and timeframe to support ease of use for middle-aged workers. Before the improvements, the risk score ranged between a ＂medium＂ load of 16 and ＂increased＂ load of 40; after the enhanced improvement program, the range of risk score was reduced to 4 (＂low＂ load) to as high as 36 (＂increased＂ load). In summary, with the analysis of KIM, the enhanced improvement program can reduce the risk score in the areas investigated in the metal plants.