Modified sitting grinder reduces complaints of musculoskeletal disorders, workload, and increases work productivity of blacksmiths in Tabanan Regency, Bali-Indonesia

Background: Blacksmith is one of the small industries that is developing in Gubug Village, Tabanan Regency. One of the processes in manufacturing household utensils in the form of small knives, large knives, sickles, and machetes will be faced with a grinder. In this process, the worker holds a vibrating grinder weighing more than 1.5 kg. Working with heavy loads and being exposed to vibration for a long time is an additional burden that will cause musculoskeletal complaints, as well as diseases such as Raynaud's Syndrome, Tenosynovitis, and Carpal Tunnel Syndrome in workers. This study aimed to determine the effect of Sitting Grinding Modification on Reducing Complaints of Musculoskeletal Disorders (MSDs), Workload, and Increasing Work Productivity of Blacksmiths in Gubug Tabanan Village.
Methods: This research is an experimental study with treatment by subject design. The population is 40 people from 10 industries. Sample selection by simple random sampling with a table of random numbers. The minimum number of samples was calculated using the Colton formula to determine the sample size to be 16 people. Data processing and analysis: Descriptive test for subject condition data includes age, weight, height, and body mass index. Normality test was performed on the data; a) physical environment includes air temperature, humidity, and noise), b). musculoskeletal complaints; c) workload; and d) work productivity. Difference test for data on musculoskeletal complaints, workload, and work productivity using parametric statistical tests (different test paired samples t-test at significance level = 0.05) in treatment I and treatment II on data that is normally distributed, and if it is not normal, non-parametric statistical tests were performed (Wilcoxon's difference test at significance level = 0.05).
Results: The mean age of the subjects was 39.00±8.52 years, body weight was 65.31±6.7.57 kg, height was 164.69±4.40 cm and the body mass index was 23.94±2.05. kg/m2. There is no difference in air temperature and humidity, there is a decrease in noise of 0.81%. There was a decrease in musculoskeletal complaints by 0.15%, a decrease in workload by 0.19%, an increase in productivity by 1.06%.
Conclusion: There is a significant decrease between musculoskeletal complaints, workload and noise before and after the use of the seated grinder (p<0.05), and there is a significant increase between work productivity before and after using modified sitting grinder.