Effect of exercise given to factory workers with ergonomics training on pain and functionality: A randomized controlled trial

1 Introduction

Work-related musculoskeletal disorders are the most common of all work-related diseases. These disorders are caused by poor posture, ergonomic inadequacies and the use of strenuous, repetitive movements [1]. Work-related musculoskeletal disorders are prevalent in many countries and result in significant economic losses. Low back pain, in particular, is one of the most common work-related musculoskeletal disorders in technologically advanced societies [2]. Low back pain is a significant musculoskeletal condition, leading to reduced productivity, workplace injuries, and loss of labor force. Activities such as carrying, pushing, pulling, holding, lowering, and lifting exacerbate the prevalence of low back pain [3]. Due to these risk factors, low back pain is common among factory workers who are exposed to physically demanding working conditions [4, 5]. Employees in the manufacturing, heavy industry, healthcare, cleaning, and service sectors are particularly susceptible to risks in the workplace [6]. Low back pain impacts fundamental activities like sitting, walking, dressing, and standing, thereby declining patients’ quality of life. It is also associated with psychological conditions such as sleep disturbance, depression and anxiety [7–9].

In addition to pharmacological interventions, non-pharmacological alternatives, including exercise and manual therapy, are also employed for low back pain management [10]. Physical activity and exercise are recommended to prevent work-related musculoskeletal disorders and improve employee performance. These programs typically include stretching and strengthening exercises [11, 12]. Several studies have demonstrated that core stabilization exercises are a highly effective technique in rehabilitating low back pain. In addition, enhancing coordination and function in deep abdominal muscles through core stabilization exercises has been shown to lessen low back pain in patients [13, 14]. In addition to physical exercise, ergonomic training has been shown to be an effective approach to managing spinal conditions [15].

In this study, we hypothesized that physical activity combined with ergonomics training for factory workers with chronic low back pain may prevent pain and fatigue in employees. There is no study in the literature on this subject, especially on factory workers. Therefore, the present study analyzed the efficacy of an exercise program consisting of core stability and stretching exercises alongside ergonomics training in improving pain, functionality, sleep, and fatigue in factory workers experiencing low back pain.

2 Methods

2.3 Randomization and blinding

The investigation was conducted as a single-blind randomized controlled trial following established principles of research design. The evaluator evaluated the study as single-blinded. Fifty-four employees from a factory participated in the study and were assigned at random to the experimental group (n:27) or control group (n:27) via a simple random method. Randomization was accomplished using a sealed envelope method.

First, a total of 60 participants underwent assessments by a medical specialist to be eligible for the trial. The trial was ultimately concluded with 54 participants. Figure 1 shows the flow of participants through the study. Inclusion criteria were defined as being between 18–65 years of age, having low back pain in the last 3 months, having a score above 4 on the Visual Pain Scale and not having undergone surgical intervention in the last 6 months. The study involved individuals who suffer from non-specific chronic low back pain. Desk work, having mental disorders, use of sleeping pills and medical conditions that prevent physical activity were the exclusion criteria for the study.

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Fig. 1

CONSORT flow diagram of the participants.

2.4 Intervention and procedure

All participants provided written informed consent. The experimental group received ergonomics training and additional training involving stretching and core exercises, while the control group only received ergonomics training. Both types of training were explained to the employees individually and supported with a written brochure. Employees were asked to perform the exercises three times a week for 8 weeks. Exercise progress was tracked and monitored through the establishment of a group using an exercise tracking chart. The initial exercises were performed with the physiotherapist, and the subsequent exercises were assigned as an individual home program. Every week, the employees received reminder messages while the study was announced both verbally and in writing to ensure maximum participant reach.

2.4.1 Exercise training

The exercise training program implemented for the participants of the experimental group (n: 27) spanned 8 weeks, with 3 sessions per week, each lasting an average of 20–30 minutes. The exercise program did not involve the use of any equipment. Before the exercise training, all participants were instructed on the abdominal corseting technique. Following its teaching, the program consisted of 5-minute stretching exercises for warm-up and posture, and 25-minute core exercises, with their movements adjusted in accordance to the capacity of each participant. The set of stretching exercises included quadratus lumborum, hamstring, erector spina, and hip extensor exercises. A posterior pelvic tilt exercise was implemented as a control and smoothing exercise for the vertebrae of the lumbar and pelvic regions. The core stabilization exercises consisted of bridging, planking, side planking, abdominal strengthening, and cross-arm leg raising exercises in the crawling position (Fig. 2). Each exercise position was held for 8 seconds, and participants were instructed to complete 10–15 repetitions. Rest intervals of 30 seconds were implemented between each exercise. Participants were instructed not to engage in any physical activity other than the exercise provided.

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Fig. 2

Exercise program applied to the participants. A: Abdominal bracing maneuver, B: Quadratus lumborum and erector spinae muscle stretching exercise, C: Hamstring muscle stretching exercise, D: Posterior pelvic tilt exercise, E: Bridging exercise, F: Plank exercise, G: Plank exercise in side lying, H: Abdominal strengthening exercise, I: Cross-arm leg raising exercise in crawling position.

2.4.2 Ergonomics training

Individual ergonomics training was given to both control group (n:27) and experimental group (n:27) participants. The training covered the definition and purpose of ergonomics, musculoskeletal diseases in employees, work-related musculoskeletal risk factors, ergonomic modifications in the work environment, and methods for preventing musculoskeletal diseases. At the start of the study, each participant received individual face-to-face ergonomics training that lasted approximately two hours. The training was presented through a combination of video, visual aids, and practical applications. Additionally, informative booklets were distributed.

3 Results

A total of fifty-four factory workers participated in the study. Demographic characteristics of the participants are presented in Table 1.

Table 2 shows the results of the pre and post-treatment assessments that were used in this study. Before treatment, there were no significant differences between the FSS, ODI, PSQI, VAS, and MPQ scores of patients in the control and experimental groups (p > 0.05). However, after treatment, a significant decrease was observed in the FSS (p < 0.001), ODI (p < 0.001), PSQI (p < 0.05), and MPQ (p < 0.001) measurements of the patients in the experimental and control groups. A substantial difference was observed between the patients in the experimental and control groups after treatment in the measures sub-parameters of PSQI. Subjective sleep quality, sleep latency, sleep time, daytime dysfunction, sleeping disorder, sleeping medicine use and PSQI total scores were significantly lower in the exercise group compared to the control group (p < 0.05). However, there was no difference between the mean measurements of habitual sleep activity and daytime dysfunction in the experimental and control groups (p > 0.05).

Table 3 represents the inter-group differences in evaluations. The exercise and control groups showed a significant decrease in the ODI, FSS, PSQI, and MPQ scores at the end of the study (p < 0.05). Also, the exercise group depicted a significantly greater decrease in ODI, FSS, PSQI, and MPQ scores than the control group in the between-group comparison (p < 0.05) (Tables 2, 3). Also, a significant difference was obtained between sleep latency and daytime dysfunction difference measurements and PSQI total score difference scores of the patients in the exercise and control groups (p < 0.05) (Tables 2, 3). There was no significant difference between the subjective sleep quality, sleep duration, habitual sleep activity, sleeping disorder and sleep medication use of the patients in the exercise and control groups.

Physical activity has been studied extensively and has been found to have a positive impact on both physiological and psychological health [19]. One of the most notable benefits of physical activity is the reduction of fatigue. Fatigue results in a reduction of problem-solving skills, a lack of focus, and decreased concentration. It therefore increases the risk of work-related accidents due to fatigue, particularly for industrial workers [20]. Biman and colleagues investigated how a 3-month yoga program affected musculoskeletal pain, fatigue, and stress in employees. Their research revealed that yoga is an effective intervention for improving fatigue levels [21]. Ramos et al. assessed the effects of transcutaneous electrical nerve stimulation (TENS) and stabilization exercises on pain, fatigue, transversus abdominis activation and functionality in patients suffering from lumbar disc herniation. The study revealed that stabilization exercises yielded favorable outcomes in all assessment criteria, including fatigue levels [22]. Stretching and stabilization exercises have been shown to reduce muscle fatigue in healthy university students [23]. In line with existing literature, our study revealed a statistically more significant reduction in pain severity (FSS) among participants who received an exercise program with ergonomics training. These findings provide evidence for the crucial role of exercise in alleviating pain among factory workers.

The decline in physical capacity, spasms, and posture among individuals experiencing low back pain results in reduced muscle strength and a decrease in their overall quality of life [24]. Multidisciplinary treatment is becoming increasingly important due to the impact of low back pain on the workforce, the high cost of treatment and the long recovery times. Complementary methods, such as massage, physiotherapy, exercises, and traction, play a significant role alongside medical interventions. Exercise has been identified as a particularly effective modality for reducing the severity of low back pain [25]. In this study, the level of functional impairment (ODI) was observed among participants who received an exercise program with ergonomics training, as well as those who received only ergonomics training. Employees who underwent an exercise program in addition to ergonomics training showed a greater decrease in functional impairment compared to the group receiving only ergonomics training. This demonstrates the positive effect of exercise on worker functionality.

Low back pain is the most prevalent musculoskeletal disorder associated with work, impacting around 45% of employees in Europe [26]. In the study, both groups exhibited high pain levels as measured by VAS and MPQ pain scores. The literature reveals numerous studies examining the impact of exercise and ergonomics training on pain among individuals employed in different industries. Several studies have highlighted the effectiveness of exercise programs in reducing pain levels among employees with chronic low back pain or neck and back pain across different occupational groups [27–30]. The study evaluated the effects of an exercise program combined with an ergonomics brochure for low back and neck pain on pain and functionality parameters among teachers. Results demonstrated that the group receiving ergonomics training along with exercise exhibited noticeable enhancements compared to those only receiving ergonomics training [27]. A study investigated the impact of ergonomics and exercise training on reducing musculoskeletal pain in automobile factory employees. The results showed a significant decrease in pain values among the employees [31]. The significance of exercise intervention in low back pain treatment is well-established, and research has focused on identifying the most effective exercise type. Recent studies have shown that core stabilization exercises are more efficacious in treating low back pain and were utilized for the experimental group’s exercise program in our study [32, 33]. In a study examining the impact of health education and stabilization exercises on low back pain among nurses, it was observed that the intervention group, which included stabilization exercises, had more significant improvements [34]. In line with the available literature, we found that the inclusion of both an ergonomics training and exercise program was effective in reducing VAS and MPQ scores among participants in our study. Another study, focusing solely on ergonomics training for operating theatre nurses, investigated the impact of a 3-month training program on musculoskeletal pain, particularly low back pain. The authors reported a decrease in the prevalence of such pain following the training program [35]. Similarly, we observed a noteworthy alleviation of pain scores in both the control and exercise groups. However, a combination of exercise programs and ergonomics training was found to be more effective in controlling functionality and pain intensity. Therefore, based on the literature and the findings of this study, an ergonomics training and physical exercise program tailored to the characteristics of the workplace for factory workers suffering from chronic low back pain may be an effective treatment to reduce pain interference and improve functionality.

In general, 50–59% of individuals suffering from chronic low back pain also encounter sleep disturbance [7, 36]. A meta-analysis of research exploring sleep quality and sleep-related issues in the industrial workforce revealed a significant incidence of sleep-related problems [37]. The current study, conducted with factory workers suffering from low back pain, indicates that both the experimental and control groups had poor sleep quality before any intervention, in line with the literature findings. Among female teachers with chronic musculoskeletal pain, Metri et al. found a positive effect of occupational yoga on sleep quality [38]. A study examining the impact of stabilization exercises on sleep disturbance in chronic low back pain patients found that these exercises led to a significant improvement in sleep disturbance scores [39]. Yoga and physiotherapy have been discovered to result in slight enhancement in sleep quality in adult individuals experiencing persistent low back pain [40]. In a systematic literature review investigating the impact of resistance or aerobic exercises on sleep quality among middle-aged and elderly individuals experiencing sleep difficulties, the evidence demonstrated a moderate improvement in sleep quality following exercise training [41]. Our study found that sleep quality improved when the exercise program was coupled with ergonomics training, which is consistent with previous literature. Furthermore, it was observed that the degree of low sleep quality vastly improved in the control group, which only received ergonomics training, comparable to the exercise group. In line with this, ergonomic training was found to be effective in improving sleep quality, pain, and quality of life in office employees [42]. Therefore, it is crucial not to underestimate the significance of ergonomics training in improving the quality of sleep and, indirectly, the quality of life for factory workers.

The study had some limitations. Firstly, the gender distribution is imbalanced, with men outnumbering women by approximately four to one. Secondly, the study did not examine the long-term impact of the intervention, which raises questions about whether the effects can be sustained over time. Finally, frequent job changes among the factory employees prevented an assessment of long-term effects.

5 Conclusion

In this study, although ergonomics training effectively alleviated high pain levels among factory workers with low back pain, the success of the intervention was further increased by adding an exercise program to the training.The results demonstrate that exercises in combination with ergonomics training effectively enhance moderately affected functionality and reduce moderate fatigue levels among workers. It has been also shown that physical activity and ergonomic training could enhance the sleep quality of employees facing sleep difficulties. Further research is required to substantiate the effectiveness of core stabilization exercises, which are more efficacious in reducing low back pain than various other exercise methods, particularly in factory workers. To enhance employee well-being, maximize work productivity, and reduce work absence caused by health problems, it is advised to undertake preventive physiotherapy services and consult experts at the institutional level for ongoing support.

Ethical approval

Ethical approval was obtained from the Uskudar University Non-Interventional Research Ethics Committee (reference number 61351342/March 2023–39).

Informed consent

All participants provided written informed consent.

Conflict of interest

None to report.