Abstract:
According to pain study of cement bag carriers who carried and arranged cement bags into the truck by using questionnaires for 15 employees found that all 15 employees (100 percents) got the pain from this work. There were 15 employees (100 percents) suffered from lower back pain, 10 employees (66.7 percents) got upper back pain while 7 employees (46.7 percents) had the arm pain. Moreover, the interview forms were used with 5 employees. The average Abnormality Index; AI was 3.152 which showed that they suffered severe pain that had to improve immediately. After that, 3 factors, EMG, AI and pressure at L5/S1 of top 5 AI employees were analyzed. The analysis was done by comparing the result of before and after improvement. In the normal working condition, the employee carried 50-kilogram-cement-bag, the average result of EMG analysis for lower left and right back muscle before improvement were 335.68 and 293.64 μv while after improvement were 64.96 and 67.16 μv, respectively. The maximum average pressure at L5/S1 before improvement was 4,965.62 (±379.65)N and after improvement was 2,347.85 (±238.34)N which was 52.72 percents lower. The average AI was reduced from 3.152 (before improvement) to 2.34 (after improvement). or 25.76 percents reduction From above information, changing working posture could reduce the value of all related factors.