INTRODUCTION
Work-related musculoskeletal disorders have become a major problem in users of video display terminals (VDT) as VDT use has increased because of increased office automation [
1,
2,
3,
4].
According to the World Health Organization, a work-related musculoskeletal disorder is defined as a disorder of the muscle, tendon, peripheral nerve, and vascular system that is generated, preceded, or aggravated by repeated or continuous use of the body [
5]. This definition focuses on repeated use and its causative role in occurrence of disease. The National Institute of Occupational Safety and Health (NIOSH) defined a work-related musculoskeletal disorder as pain, spasticity, and burning or tingling sensations in the neck, shoulder, elbow, forearm, wrist, or hand that last for longer than one week or appear at least once a month for one year [
5].
In Korea, studies about work-related musculoskeletal disorders in VDT workers have mostly addressed the prevalence and risk factors of symptoms of the neck and upper extremities. These studies have mainly been conducted in the fields of occupational and environmental medicine and have mostly concerned the diagnosis and prevalence of work-related musculoskeletal disorders [
1,
3,
5].
Currently, education on muscle-relaxing exercises and regular joint and muscle-strengthening exercises is usually assigned in order to prevent musculoskeletal disorders in worker who perform repetitive upper extremity tasks such as VDT use. In the case of mild pain, physical and exercise therapy have been widely recommended [
6,
7]. However, in recent studies, exercise and ergonomics did not significantly reduce musculoskeletal disorder symptoms [
8,
9,
10]. In spite of this controversy, there have been few instances in which rehabilitation education has been tailored to the individual characteristics of musculoskeletal disorders based on accurate diagnosis. Accordingly, there have also been few reports about the effects of rehabilitation education or symptom change after rehabilitation education.
Therefore, in this study, we conducted a survey to analyze changes in and characteristics of musculoskeletal symptoms after tailored rehabilitation education among VDT workers with work-related musculoskeletal disorders.
DISCUSSION
The VDT workers in the present study complained of pain in the order of shoulder, neck, low back, elbow, wrist, and lower extremity. Park et al. [
15] reported that the prevalence of pain complaints among 290 female international telephone operators was significantly greater in the shoulder (65.2%) and upper extremities (50.0%), followed by the neck (38.6%), low back (36.2%), hand (34.5%), back (29.0%), and lower extremities (24.8%). This study demonstrated that VDT work mainly caused shoulder-arm-neck pain. In addition, the prevalence of muscle tenderness was significantly higher in the shoulder and upper extremities, followed by the back (6.2%), neck (5.2%), low back (2.8%), hand and fingers (2.4%), and lower extremities (1.0%). In addition, muscle tenderness on the right side upper extremities, neck, and shoulder was significantly severer than it was on the left side [
15].
Bernard et al. [
16] reported that the prevalence of musculoskeletal disorders of the upper extremities including the neck and shoulder was 41% among newspaper employees, and the prevalence of hand or wrist disorders was 22%. Bergqvist et al. [
17] also found that symptom prevalence of neck and shoulder disorders was 61.2% and that the rates of neck and shoulder disorders were 22.7% and 13.0%, respectively, among VDT workers. These studies demonstrated similar results to our study, in which shoulder pain was the most common, followed by pain in the neck, low back, elbow, wrist, and lower extremities.
In a previous study related to rehabilitation education, Shuai et al. [
6] evaluated the effects of an educational program for preventing work-related musculoskeletal disorders among 350 school teachers. They evaluated the program effects after 6 and 12 months using a questionnaire. The educational program contained an occupational health lecture, approximately 40 minutes long, that explained musculoskeletal disorders and risk factors and introduced ergonomic training to improve posture while at the computer. After the intervention, there was an improvement in awareness, attitudes, and behavior associated with work-related musculoskeletal disorders and a significant decrease in discomfort or pain in the neck, shoulder, and low back. These results were similar to those in our study. These results collectively suggest the importance of rehabilitation education for managing work-related musculoskeletal disorders. In addition, the educational program in the study described above was similar to that in our study with regard to explaining the characteristics of musculoskeletal disorders and education on correct working posture. However, there were differences between the studies in that additional exercise education and improvements in the working environment were provided in our study, in addition to our production of an educational booklet and video with free educational content uploaded on a website in order to increase the access to information to the subjects in our study.
de Freitas-Swerts et al. [
18] evaluated the effects of office exercise on reduced work-related stress and musculoskeletal pain. They reported that there was no significant reduction in work-related stress. However, there was a significant decrease in pain in the upper, middle, and lower back; right thigh; ankle; and foot and left leg. Their study also assigned postural exercises, segmental stabilization, and segmental and muscular chain stretching for both the upper and lower extremities. This might explain the difference in results compared with our study.
However, in recent studies, no significant effects of exercise and workplace adjustments have been shown for work-related musculoskeletal pain. For example, Karjalainen et al. [
9] reported that multidisciplinary biopsychosocial rehabilitation showed no effectiveness on work-related musculoskeletal disorders. In addition, Verhagen et al. [
10] analyzed 44 studies of 6,580 persons to examine the effects of exercise, ergonomics, and physical therapy on work-related complaints of neck, shoulder, or upper extremity discomfort. Twenty-one studies evaluated the impact of exercise on work-related musculoskeletal pain, 13 evaluated ergonomic workplace adjustments, and nine evaluated behavioral interventions and other various treatments, excluding injections and surgical procedures. All of these studies reported no effect of exercise on pain, recovery, disability, or sick leave. However, ergonomic interventions did decrease pain in the long term, although not in the short term. A possible reason for the different results compared with our study is that exercise therapy including specific forms of exercises such as proprioceptive neuromuscular facilitation, Feldenkrais therapy, and Mensendieck training were provided to participants with nonspecific neck and shoulder pain, whereas we subdivided exercises into muscle-specific stretching and strengthening exercises according to actual diagnosis and conducted repeated and constant education. The results of our study including tailored rehabilitation education depending on accurate diagnosis could therefore be more clinically meaningful. In addition, to improve the working environment, we provided education on ergonomic training to improve computer working posture as a part of the tailored rehabilitation education and followed up after one year. In this regard, of our study results corresponded with those in the above meta-analysis.
Our study found that pain duration, intensity, and frequency were significantly decreased in the shoulder and wrist after tailored rehabilitation education, pain intensity was significantly decreased in the neck area and pain duration and frequency were significantly decreased in the low back area. This suggests that providing musculoskeletal rehabilitation education, including explanations of specific disease characteristics, exercise therapy, and posture education, to VDT workers is an important part of pain management. In the low back pain group, there was no significant difference in pain intensity; however, there was a decrease in the number of subjects who complained of moderate and severe pain, suggesting that musculoskeletal rehabilitation education was effective in alleviating pain intensity.
In the elbow pain group, the values of the three evaluation factors decreased, but this was not statistically significant. In the lower extremity pain group, there were no significant changes in any of the evaluation factors. A possible explanation might be that the components of our musculoskeletal rehabilitation education mainly focused on the neck, shoulder, and hand regions. With regard to the content of rehabilitation education used in our study, we think it will be necessary to revise the education so that it can be appropriately applied to all body parts, including the characteristics and symptoms of work-related musculoskeletal disorder, posture training, and exercises for the elbow and lower extremities. In the comparison between the severe and mild pain groups, pain duration, intensity, and frequency were more significantly decreased in the mild pain group than in the severe pain group. This suggests that musculoskeletal rehabilitation education was more effective in decreasing relatively mild pain, including myofascial pain syndrome. It also suggests the importance of medical examination for screening severe symptoms when planning a musculoskeletal rehabilitation education program in a large-scale work setting.
There were a number of limitations to the present study. First, this study is likely to have been influenced by the subjective tendency of respondents because of the nature of a self-report survey. To supplement this, additional study needs to be conducted with direct observation or the interview method in the future. Second, because this was a cross-sectional study, it only examined the changes in pain duration, intensity, and frequency; as such, we could not assess the effects of other psychological factors including occupational satisfaction and stress. Third, we did not consider work environment factors such as sitting position, desk height, or chair type in association with the occurrence of work-related musculoskeletal pain. Fourth, we were not able to evaluate the effects of the duration of education. Also, we did not investigate whether subjects received additional treatment other than rehabilitation education. Fifth, we were not able to set up a control group because of the nature of survey research in a large-scale work setting. In addition, many subjects were lost to follow-up. We were not able to compare the degree of decrease in pain in each body part after rehabilitation education because of the small number of subjects with pain in all body parts. Therefore, we could not analyze the region-specific effects of rehabilitation education. Large-scale prospective studies including a control group are needed in the future.
However, in spite of the above limitations, our study has clinical significance for identifying the usefulness of rehabilitation education that can easily be overlooked when analyzing symptom changes in work-related musculoskeletal patients after musculoskeletal rehabilitation education. In addition, our study differed from others in that tailored rehabilitation education was conducted according to accurate diagnosis. Therefore, our study provides useful data for establishing effective teaching methods for rehabilitating work-related musculoskeletal injury.
In conclusion, our study analyzed changes in musculoskeletal pain through disease-specific tailored rehabilitation education among VDT workers. Generally, the workers' musculoskeletal symptoms were improved after musculoskeletal rehabilitation education. In particular, there were significant decreases in pain in the shoulder, wrist, and low back regions. In addition, after musculoskeletal rehabilitation education, there was a greater decrease in pain in the mild pain group compared with the severe pain group.