Effectiveness of a Participatory Program for Preventing Work-Related Musculoskeletal Disorders among Slaughterhouse Workers in Thailand | ||
| Health Education and Health Promotion | ||
| Article 20, Volume 13, Issue 2, 2025, Pages 347-356 PDF (421.24 K) | ||
| DOI: 10.58209/hehp.13.2.347 | ||
| Authors | ||
| R. Sompan* 1; O. Keeratisiroj2 | ||
| 1Department of Occupational Health and Safety, School of Public Health, University of Phayao, Phayao, Thailand | ||
| 2Department of Community Health, Faculty of Public Health, Naresuan University, Phitsanulok, Thailand | ||
| Abstract | ||
| Aims: This study aimed to develop a model for injury prevention through a participatory work-related musculoskeletal disorders (program designed to reduce localized pain across various body regions among workers in pig production slaughterhouses in Thailand. Materials & Methods: This quasi-experimental study was conducted in 40 slaughterhouse workers who participated in a program designed to prevent work-related musculoskeletal disorders. The prevention program comprised four core activities. Self-administered questionnaires were used to assess the prevalence of work-related musculoskeletal disorders before and after the intervention. Statistical analyses were performed using SPSS 17 software by Chi-square and paired t-tests. Findings: There was a significant reduction in work-related musculoskeletal disorders following the prevention program in four areas, including upper arms (p<0.001), hands/wrists (p=0.049), calves (p=0.031), and feet (p=0.007). Furthermore, the severity of pain associated with work-related musculoskeletal disorders was significantly reduced after the intervention (t=7.654; p<0.001). Conclusion: A workplace-based work-related musculoskeletal disorder prevention program is effective in reducing musculoskeletal discomfort and improving ergonomic practices among workers. | ||
| Keywords | ||
| Ergonomic; Social Participation; Slaughterhouse; Musculoskeletal Diseases | ||
| Full Text | ||
|
Introduction Work-related musculoskeletal disorders (WMSDs) have a significant impact on mobility and physical function, often leading to early retirement, reduced quality of life, and limited social participation. With the growing population and aging workforce, the prevalence of WMSDs and associated disabilities is rapidly increasing, making it a critical occupational health issue globally. Several countries, including the United States, the United Kingdom, Germany, and Japan, officially recognize WMSDs as occupational diseases eligible for compensation [1, 2]. In the United States, WMSDs are among the most common occupational diseases, particularly affecting workers in jobs that require prolonged standing or sitting. In 2020, WMSDs accounted for 31.0% of all occupational illnesses [3]. In 2021, a study conducted in Venezuela found that 77% of the population experienced musculoskeletal discomfort. The most commonly affected areas were the shoulders, back, hands/wrists, and neck, with prevalence rates ranging from 83.3% to 90.2%, respectively [4]. Similarly, data from Thailand’s Social Security Office indicate that injuries and illnesses related to musculoskeletal disorders ranked highest in incidence for five consecutive years, from 2018 to 2022. According to the Social Security Administration, the incidence rates of WMSDs in Thailand were 2017 (84.54%), 2018 (80.70%), 2019 (80.79%), 2020 (84.66%), and 2021 (72.59%) [5-9]. The meat processing industry involves the slaughtering, processing, and packaging of pork for human consumption. The process begins with slaughtering the animal and extracting the blood. The carcass is then opened to remove internal organs and thoroughly cleaned. Afterward, the meat is divided into various cuts. Workers in the observed facilities manually cut the meat. Finally, semiautomated production lines weigh and package the meat, depending on the specific product requirements. The industry is particularly susceptible to WMSDs due to the high physical demands of the job. Tasks such as repetitive lifting, prolonged standing, and manual handling of raw materials are associated with musculoskeletal discomfort and injuries [10]. Studies from Iran and Poland have revealed high prevalence rates among meat industry workers, with common complaints, including lower back pain (38.0%, 64.0%), knee pain (40.0%, 24.0%), and neck pain (24.0%, 42.0%). Similarly, 64.9% of meat processing workers in New Zealand reported pain in their hands/wrists, while 54.8% experienced pain in multiple body regions, including the limbs and neck [11]. In Denmark, slaughterhouse workers report high rates of pain in the neck (48.0%), shoulders (60.0%), elbows (40.0%), and hands/wrists (52.0%) [12]. Nigerian butchers exhibit a prevalence of 66.7% for lower back pain and 45.1% for hands/wrists, with age identified as a significant risk factor [13, 14]. The meat processing industry is characterized by factors that contribute to a high prevalence of musculoskeletal discomfort among workers. These factors include high production volumes, physically demanding tasks, manual handling of raw materials, frequent lifting of heavy weights, and the need for sustained mental concentration due to the variety of products being processed. It is important to emphasize that meat cutters face significantly higher risks of injuries and musculoskeletal problems compared to most other occupational groups. The regulatory standards for the slaughter and meat processing industries recommend implementing job rotations to improve worker safety and reduce risks. These rotations should meet at least one of the following criteria: changing working positions, alternating the use of muscle groups, performing tasks that minimize repetitive motions, or reducing the physical strain caused by lifting and handling heavy loads [15, 16]. According to a previous study, approximately 13% of tasks in slaughterhouses were identified as high-risk for upper extremity WMSDs, with risk levels exceeding 21.5%. Moreover, a moderate level of risk was observed in tasks with risk levels ranging from 10.8% to 21.5% [17]. Therefore, this study aimed to evaluate the effectiveness of intervention programs for pig slaughterhouse workers, with a focus on ergonomic strategies, training, and posture support. Materials and Methods Design and sampling This quasi-experimental study was conducted from November 2021 to January 2022 among 108 pig production slaughterhouse workers in the Muang Ang Thong district of Thailand. The sample size was calculated based on the proportion of WMSDs from a quasi-experimental study conducted by Krungkraipet [18]. Using the comparative proportional formula, a minimum sample size of 37 participants was required. To account for potential attrition, the sample size was increased by 10%, resulting in 40 participants who were selected through quota sampling [19]. The analysis of occupational tasks and work processes was conducted with the participation of ten individuals, each possessing over one year of professional experience and demonstrating a comprehensive understanding of their respective roles. Instrument The measure of prevalence of WMSDs had three sections; sociodemographic information (gender, age, marital status, body mass index, smoking, and alcohol consumption), work-related information (work duration, additional occupational positions/job tasks), and a modified version of the standard Nordic Musculoskeletal Questionnaire (NMQ) adapted for the Thai context. This questionnaire assessed musculoskeletal symptoms across 12 anatomical regions (neck, shoulders, upper back, lower back, upper arm, elbows, lower arm, hands/wrists, hips/thighs, knees, calves, and feet). Participants reported experiencing soft tissue pain or discomfort within two time frames: the past 12 months and the past seven days. The NMQ, developed by Kuorinka et al., is a widely validated and reliable tool for diverse populations and settings. Its brevity and ease of completion (taking approximately five minutes) make it especially advantageous for occupational health studies [20]. Procedure All participants provided written informed consent before study enrollment. The participatory program included five main components; identifying WMSDs using a body map, defining and demonstrating proper work procedures, distribution of WMSDs by body region (pre- and post-intervention analysis), providing knowledge on WMSD prevention and management, and comparing WMSD severity among participants before and after the quasi-experimental study. Throughout the research process, participant confidentiality was protected, and data security measures were strictly implemented in accordance with institutional guidelines. Two occupational health and safety experts conducted the educational session, and the curriculum encompassed ergonomic principles and workplace environmental modifications. The two-day training program, comprising both theoretical instruction and practical applications, focused on postural correction and muscular conditioning for the prevention of WMSDs. The analysis of occupational tasks and work processes was conducted through structured interviews, utilizing closed-ended questions to elicit detailed insights into their task characteristics. Training on the prevention and management of musculoskeletal disorders was conducted by two experts specializing in occupational health and safety. Data analyses Statistical analyses were performed using SPSS 17 software. The prevalence of WMSDs in different body regions was compared before and after the intervention using the Chi-square test. Differences in WMSD severity scores between the pre- and post-intervention periods were analyzed using paired t-tests, as the data met the normality assumption, verified using the Shapiro-Wilk test. A significance level of p<0.05 was applied to all analyses. Findings The mean age of participants was 34.15±8.27 years. 62.5% were married, mostly had completed primary education (42.5%), 45.0% had a normal BMI (18.5-22.9kg/m²), and the majority were non-smokers (55.0%; Table 1). Table 1. Frequency of demographic characteristics of sample slaughterhouse workers in Muang Ang Thong District, Thailand (n=40)   Most participants experienced mild symptoms. The highest prevalence of WMSD symptoms was observed in the hand/wrist (n=30) and the lowest prevalence was found in the upper back (n=8); Table 2). Table 2. Frequency of work-related musculoskeletal disorders by body region using body mapping assessment (n=40)  The occupational task analysis and work process documentation included an exchange of experiences related to working methods and equipment for each step of the ten tasks (Table 3). Table 3. Occupational task analysis and work process  There was a statistically significant reduction in WMSD severity (t=7.654; p<0.001). There were statistically significant differences before and after the intervention in upper arms (p<0.001), hands/wrists (p=0.049), calf (p=0.031), and foot (p=0.007; Table 4). Table 4. Comparing the distribution of work-related musculoskeletal disorders symptoms according to the body regions before and after the intervention by paired t-test  Discussion This study aimed to evaluate the effectiveness of intervention programs for pig slaughterhouse workers. Meat processing workers predominantly performed tasks requiring repetitive hand and arm movements, resulting in the highest prevalence of hand/wrist pain (75.0%), followed by lower arm (52.0%) and shoulder (42.5%) discomfort. This is somewhat similar to a study on slaughterhouse workers in the South Island, reporting a 64.9% prevalence of musculoskeletal disorders among meat processing workers, with hand/wrist symptoms accounting for 54.8% of cases [20]. Similarly, findings from a study on poultry slaughterhouse workers in Santa Catarina, Brazil, indicated that the most frequently affected body regions are the shoulders (62.6%), neck (46.2%), spine (36.4%), forearms (31.3%), arms (29.2%), and hands/wrists (25.6%) [21]. In northern Thailand, the prevalence of work-related musculoskeletal pain (WMSP) among poultry slaughterhouse workers is highest in the shoulder region (61.5%) over the past seven days, followed by the wrists/hands (60.3%) and lower back (35.9%) [22]. Similarly, for the past 12 months, the prevalence has remained high in the same regions, with the shoulder (61.5%), wrists/hands (60.3%), and neck (37.1%) being the most affected areas. Overall, the severity of WMSP across all body regions is classified as mild to moderate, underscoring the significant yet manageable impact of musculoskeletal discomfort on this workforce [23]. Following the three-month intervention, the factory introduced revised work protocols, including mandatory 15-minute rest breaks after every two hours of continuous work. This approach aligns with the findings of Dias et al. [24], reporting that a work-rest schedule comprising six 10-minute breaks is more effective than three 20-minute breaks in reducing the risk of upper limb WMSDs among poultry slaughterhouse workers. As a result of the intervention, a significant reduction in WMSDs was observed, particularly in the upper arms, hands/wrists, calves, and feet. These improvements are attributed to behavioral modifications, including ergonomic training, enhanced manual handling techniques, and the structured work-rest schedule. Ergonomic education played a crucial role in increasing awareness of occupational hazards and mitigating muscle fatigue [25]. These findings are consistent with previous studies by Hancharoenkul et al. [26] and Denadai et al. [27], demonstrating the effectiveness of ergonomic training in reducing musculoskeletal complaints and pain intensity among both novice and experienced meat industry workers. Denadai et al. further emphasized that training is more accessible for novice workers and that biomechanical exposures varied by experience level, especially in cutting room tasks. These insights underscore the importance of tailoring ergonomic interventions to the worker’s experience and task characteristics to optimize effectiveness and promote long-term adoption. We demonstrated the effectiveness of a workplace-based WMSDs prevention program in reducing musculoskeletal discomfort and improving ergonomic practices among workers. Positive outcomes included symptom reduction, improved awareness, and behavioral changes, supported by rest breaks and ergonomic adjustments. Although limited by its setting and short-term scope, the findings suggest that participatory interventions, combined with organizational support, can enhance occupational health. Future studies should explore long-term effects and integrate psychosocial and work-related factors to strengthen generalizability and impact. Conclusion A workplace-based work-related musculoskeletal disorders prevention program is effective in reducing musculoskeletal discomfort and improving ergonomic practices among workers. Acknowledgments: We would like to thank all the workers of the pig slaughterhouse in the town municipality of Ang Thong, Thailand, for participating in this study. Ethical Permissions: The official research ethical approval code for the current study is IRB No. P10188/64 and Certificate of Approval No. is 456/2021, granted by the Human Research Ethics Committee of Naresuan University, Thailand. Conflicts of Interests: The authors declared no conflicts of interests. Authors' Contribution: Sompan R (First Author), Introduction Writer/Methodologist/Main Researcher/Discussion Writer/Statistical Analyst (70%); Keeratisiroj O (Second Author), Methodologist/Assistant Researcher/Discussion Writer/Statistical Analyst (30%) Funding/Support: The authors received no financial support for the research, authorship, and/or publication. | ||
| References | ||
|
| ||
|
Statistics Article View: 39 PDF Download: 19 |
||
Statistics
| Number of Journals | 45 |
| Number of Issues | 2,171 |
| Number of Articles | 24,674 |
| Article View | 24,436,496 |
| PDF Download | 17,551,440 |