## 4 Discussion  
This study used structural equations to analyze the relationship between work-family conflict, musculoskeletal pains, sleep-related problems, and well-being among workers in the food manufacturing industry. The research results show that work-family conflict has an impact on musculoskeletal pain. This finding is consistent with research indicating that work-family conflict can lead to musculoskeletal symptoms such as neck and back pain [8, 30, 31, 32]. Work-family conflict has also been shown to affect sleep-related problems. This is consistent with the results that the greater the work-family conflict, the higher the risk of waking up multiple times at night, the difficulty in falling asleep again, as well as the likelihood of sleep-related problems such as waking up tired [68, 69, 70]. The results are consistent with the findings that construction workers and IT workers experience sleep-related problems due to work-family conflict [71, 72]. As work hours increase, work-family conflict may worsen [73, 74]. Thus, managing work hours of food manufacturing workers can reduce work-family conflict. Musculoskeletal pain has also been shown to contribute to sleep-related problems. This is in line with research indicating that musculoskeletal pain can have a negative impact on both the quantity and quality of sleep, resulting in difficulty falling asleep and conditions such as insomnia, narcolepsy, and sleep apnea [9, 10, 40, 41, 42, 43]. In addition, the sleep quality of workers in hospitals and electronic component manufacturing plants was found to be linked to musculoskeletal pain [38, 75]. Musculoskeletal pain has been shown to have a negative impact on well-being. This was consistent with the finding that the group complaining of musculoskeletal pain had lower overall psychological well-being than the non-complainers [76, 77] and that musculoskeletal pain had a negative effect on psychological well-being [78]. These results suggest that preventing musculoskeletal pain is important to improve the well-being of food manufacturing workers. Food manufacturing workers are prone to musculoskeletal pain because they use hand tools, handle heavy objects, and perform repetitive tasks [79, 80]. Physical therapy for patients with neck, shoulder, or back pain can improve not only pain but also psychological well-being [81]. Appropriate education is also important to understand the causes and prevention of musculoskeletal pain [1, 81]. Figure 2: Final SEM of this study. Rectangle represents measurement variable, and ellipse represents latent variable. D\({}_{i}\); disturbance or residual; e\({}_{i}\): measurement error. This study presents effective measures to manage food manufacturing workers' well-being, sleep problems, musculoskeletal pain, and work-family conflict. First, musculoskeletal pain is the factor that most directly affects well-being, suggesting that managing workers with musculoskeletal pain is paramount. In particular, it is necessary to manage food manufacturing workers' upper limb, back, and lower limb pain. Second, the sleep-related problems of food manufacturing workers were influenced by musculoskeletal pain and work-family conflict, and it was found that musculoskeletal pain was particularly affected among the two. Third, because the presence of musculoskeletal pain is influenced by work-family conflict, this suggests that efforts are needed to reduce work-family conflict factors. In particular, efforts are needed to improve major factors in work-family conflict, such as \"not giving time to work because of family\" and \"difficult to concentrate on work because of family\". Lastly, integrated management using structural relationships is needed for well-being, sleep problems, musculoskeletal pain, and work-family conflict. This study has some limitations. First, this study did not target the entire food manufacturing industry, so caution is needed in interpretation.