Ergonomically designed working environment to reduce the effects of hand-arm vibration in industry / Nurul Hanna Mas'aud.

worker's risk and vibration impact on upper trapezius muscle. Then, ergonomic working environment will be designed to reduce the vibration effects among manufacturing workers. The data on musculoskeletal disorders (MSDs) symptoms of pain and the workers' risks of exposure to vibration were collected via questionnaire and Rapid Upper Limb Assessment (RULA). The muscle activity and muscle fatigue were measured using Electromyography (EMG). After implementing the ergonomic
designed working environment, satisfaction survey was conducted to get feedback from workers as well as to verify and justify the ergonomic designs. The research outcome found that the ergonomic designs of hand-arm vibration exposure caused the workers to experience pain, especially on the right shoulder (60.7 percent). The RULA result found that 50 percent of the workers score 3 or 4, 28.6 percent score 5 or 6 and 21.4 percent score 7. The EMG result found that 67 percent of the workers are
in fatigue condition. The EMGRMS maximum peak value js 305.49uV. It is then concluded that the muscle is in fatigue when the EMGRMS value is increasing and EMGMPF value is decreasing. The starting point of fatigue is generally found after 90 minutes to 120 minutes for both male and female workers. Therefore, six designs of ergonomic working environment were introduced and implemented for trial production: (a) standing block, (b) job rotation, (c) using fingerless anti-vibration glove, (d) nylon glove and rubber ring, (e) stretching program, and (f) using anti-fatigue mat. After implementing four designs of ergonomic environment, the percentage of pain occurring on the body parts was decreased, RULA score was reduced, and muscle no more in fatigue. Most of the workers are satisfied, they felt happy and comfortable. Overall, it raised the awareness of ergonomic among the workers and the organization.