Reduction of low back muscular discomfort through an applied ergonomics intervention program.

An applied ergonomics intervention program (AEIP) was conducted with male employees who work in the pressing and storage sections of a metal auto parts factory in eastern Thailand. The objective of this study was to reduce worker muscular discomfort at the low back. The study design was a participatory research approach, with quasi-experimental pretest-posttest, and with a non-equivalent control group. Thirty-five persons participated in the AEIP (AEIP group) and 17 persons did not (non-AEIP group). The AEIP was composed of three major categories: (1) top management support; (2) equipment designed for workstations and manual material handling; and (3) administrative intervention, training, and health education. Muscle activity was measured by surface electromyography of the left and right erector spinae, and multifidus muscles; and evaluated by multivariate test for dependent samples (paired observation) and for independent samples. After the AEIP, the low back muscular loads of the AEIP group was significantly reduced, while those of the non-AEIP group were not. Comparison of the means of percentage maximum voluntary contractions (% MVC) of low back muscular activity between the AEIP group and non-AEIP group indicated that the AEIP group had significantly reduced low back muscular load, with a 95% confidence level (p-value < 0.05).

The health of workers in a metal autoparts factory in eastern Thailand.

One hundred and seventy-two male employees working in the pressing and store sections of a metal autoparts factory in eastern Thailand participated in the study. The aim of this study was to survey the health and well-being condition of Thai workers prior to corporation initiatives in applied ergonomics with the workers of the company. A retrospective study of official accident information, and questionnaires regarding general information, health, muscular discomfort, accidents, posture disorders, and subjective feelings of fatigue or discomfort were filled out for the survey. The results of the study provided 48 categories of important information on the health and wellness of the employees in their workplace. Regression analysis revealed that, based on the working history of the employees, the small and large pressing sections of the workplace had a greater impact on the muscular discomfort of the employees (0.322) (p = 0.001). Based on the health information, the independent factors influencing the employee's muscular discomfort were frequency of muscular discomfort (0.240) (p = 0.004), no disease of muscle and bone (0.165) (p = 0.025), and finally, regularly taking medicine for muscular pain (0.163) (p = 0.024). The factors influencing accidents in the employees were working where they could be cut by sharp material or metal (0.257) (p = 0.008), muscular discomfort (0.169) (p = 0.059), and not using protective equipment (0.146) (p = 0.076). Thus the applied ergonomics intervention program for preventing worker injuries in the sections studied should be implemented, in order to promote the health and well-being of the employees.

An ergonomics intervention program to prevent worker injuries in a metal autoparts factory.

An ergonomics intervention program (EIP) was conducted with male employees working in the pressing and storage sections of a metal autoparts factory in Samut Prakan Province, Thailand. The objectives of this study were to assess the causes of injuries in the pressing and storage sections of that factory, and to improve working conditions by reducing worker injuries from accidents and low back muscular discomfort, using an EIR The study design used a participatory research approach which was quasi-experimental with pretest-posttest evaluations, with a non-equivalent control group. A total of 172 male participants working in Building A were the target group for assessing causes of injury. A retrospective study of official accident information, and questionnaires for general information, health and muscular discomfort, injury frequency rate (IFR), injury severity rate (ISR), medical expenses, and EIP design. Two groups of employees volunteered for the study on muscular back discomfort. The first group of 35 persons volunteered to participate in the EIP (EIP group), and the second 17 persons from Building B did not (non-EIP group). The EIP was composed of 4 major categories: (1) engineering improvement, (2) change in personal protective equipment, (3) environmental improvement, (4) administrative intervention, training, and health education. Low back muscular discomfort was measured through questionnaires on subjective feelings of muscular discomfort, and by surface electromyography (sEMG). Muscle activities were measured by sEMG of the left and right erector spinae and multifidus muscles, and evaluated by multivariate test for dependent samples (paired observation), and multivariate test for two independent samples. After EIP, IFR decreased 65.46%, ISR decreased 41.02%, and medical expenses decreased 42.79%. The low back muscular loads of the EIP group were significantly reduced, with a 95% confidence level (p < 0.05) while those of the non-EIP group were not. Subjective feelings of muscular discomfort, determined by Wilcoxon Signed Ranks test, showed that after applying the EIP to the EIP group, the mean scores for general bodily discomfort and low back muscular discomfort in the EIP group had significantly reduced, while those of the non-EIP group increased, (p < 0.05).