Risk factors for work-related low back pain in the People's Republic of China

The effects of psychological distress after surgery in patients undergoing lumbar spinal fusion

BACKGROUND

The aim of this study was to evaluate the psychological distress pre-operatively, at 3, 6, and 12 months in patients who underwent lumbar spine fusion surgery.

METHODS

A total of 440 patients received instrumented lumbar spine fusion were enrolled. Psychological distress was evaluated using the Modified Somatic Perception Questionnaire (MSPQ) and the Modified Zung Depressive Index (ZDI). The results of lumbar fusion surgery were evaluated using the Oswestry Disability Index (ODI), the Japanese Orthopedic Association (JOA-29), and the visual analog scale (VAS).

RESULTS

Psychological distress was reported among 23% of patients and 7, 5.5, and 4.0% of the patients preoperatively, at 3, 6, and 12 months after lumbar surgery, respectively. The mean MSPQ score decreased from 8.78 (before surgery) to 4.30, 3.52, and 3.43 at 3, 6 and 12 months in after surgery, respectively, in patients with psychological distress patients (p < 0.001). The mean ZDI score decreased from 17.78 to 12.48, 10.35, and 9.61 (p < 0.001). The mean ODI score decreased from 22.91 to 11.78, 10.13, and 9.96 (P < 0.001). The mean JOA score increased from 13.65 to 22.30, 23.43, and 23.61 (P < 0.001). The mean low back pain (LBP) VAS score decreased from 4.48 to 1.96, 1.52, and 1.51 (P < 0.001); moreover, the mean leg pain (LP) VAS score decreased from 5.30 to 1.30, 1.04, and 1.03 (P < 0.001).

CONCLUSIONS

Patients with psychological distress may experience surgical intervention benefits equal to those of ordinary patients. Moreover, reduced pain and disability after surgical intervention may also alleviate psychological distress. Hence, we highly recommend that patients with psychological distress undergo surgical intervention as normal patients do, but appropriate screening measures and interventions are necessary.

Time trends in the burden of low back pain and its associated risk factors in China from 1990 to 2019

Background

From 1990 to 2019, low back pain (LBP) was the leading cause of years lived with disability (YLDs) in China. However, the change patterns of LBP and its risk factors in China remain unclear.

Methods

Data from the Global Burden of Disease Study 2019 were used. We used the join-point regression model and age-period-cohort analysis to evaluate the time trends of attributable risk factors on the burden of LBP.

Results

In 2019, the risk factors included in this analysis accounted for 4.36 million YLDs of LBP, representing 42.2% of all YLDs of LBP in China, with 2.86 million due to occupational ergonomic factors, 1.74 million due to smoking, and 0.46 million due to high body mass index (BMI). The age-standardized YLD rates of LBP showed downward trends during 1990-2019, while there was a faster decline between 1990 and 1994. The curves of local drifts, which reflected the average annual percentage change across age groups, showed an increasing trend with age for high BMI and smoking, and a downward trend for occupational ergonomic factors. The YLD rates for LBP increased dramatically with age for high BMI, while it reached a peak at 40-60 years old for occupational ergonomic factors, and 65-80 years old for smoking. The period and cohort rate ratios of LBP YLD decreased in the past 3 decades for occupational ergonomic factors and smoking, while increased for high BMI.

Conclusions

Our results provided strong evidence that there were diverse changing patterns for different risk factors, highlighting the need for risk-specific strategies.

The translational potential of this article

China has the largest senior population and the fastest aging population in the world. Given that LBP typically occurs in the senior population, there would be an increasing LBP burden on China's health system. This suggests that effective strategies for LBP prevention should be strictly implemented in China, particularly in the senior population, which is of crucial translational potential.

Low back pain and telecommuting in Japan: Influence of work environment quality

Objectives

This study examined the relationship between frequency of working from home and low back pain (LBP), considering the quality of work environment.

Methods

The study was based on a cross‐sectional internet‐based survey. Of 33 302 respondents, data from 12 774 desk workers were retained for analysis. We used a 0–10 numerical rating scale to assess LBP. Work environment was assessed using five subjective questions. Mixed‐effects logistic regression nested by city level was used to analyze the relationship between frequency of working from home and LBP, stratified by work environment condition.

Results

The prevalence of LBP was 21.0%. Among those reporting a poor work environment, as opposed to almost never working from home, the multivariate odds ratio (OR) of LBP were as follows: working from home less than 1 day per week: OR = 1.25, 95% CI: 0.89–1.76, p = .190; 2–3 days per week: OR = 1.58, 95% CI: 1.16–2.16, p = .004; and 4 or more days per week: OR = 1.82, 95% CI: 1.38–2.40, p < .001. By contrast, among those reporting a good work environment, the OR of LBP did not increase as the frequency of working from home increased.

Conclusions

The relationship between LBP and frequency of working from home was found to vary with the quality of the work environment; more specifically, LBP was associated with frequency of teleworking in a poor work environment. This study suggests that employers should give more support to their employees in promoting a good work environment to prevent LBP. (Words: 240/250).

Association Between Telecommuting Environment and Low Back Pain Among Japanese Telecommuting Workers: A Cross-Sectional Study

OBJECTIVES

We evaluated the relationship between telecommuting environment and low back pain (LBP) among desk-based workers in Japan.

METHODS

This cross-sectional study included 3663 desk-based, telecommuting workers. LBP was assessed using a 0 to 10 numerical rating scale. The telecommuting environment was evaluated using subjective questions. Mixed-effects logistic regression analysis was used to evaluate this association.

RESULTS

The results of mixed-effects logistic model revealed that not having a place or room to concentrate on work, desk not well-lit enough for work, lack of space on the desk to work, not having enough legroom, and uncomfortable temperature and humidity conditions in the workspace were significantly associated with higher odds of LBP.

CONCLUSIONS

Our findings suggest that telecommuting environment is associated with the prevalence of LBP.

Preventive factors against work-related musculoskeletal disorders: narrative review

Musculoskeletal disorders (MSDs) are major causes of morbidity among workers. They comprise several signs and symptoms, as e.g. pain, paresthesia, fatigue and limited range of motion, which can be related to work tasks. Workplace-related factors include physical, psychological, social and biomechanical hazards. The main kinetic factors associated with MSDs include repetitive movements, exerting excessive force, awkward postures, compression and mechanical vibration. Accurate knowledge of epidemiological aspects, evaluation of ergonomic hazards and musculoskeletal symptoms, and workplace exercise may help reduce the occurrence of MSDs. The aim of the present review is to analyze the applicability of preventive strategies against MSDs among workers. We performed a narrative review based on a survey of databases PubMed and BIREME and included studies published in English, Spanish or Portuguese. We found that workplace exercise is beneficial for both employers and workers. Risk analysis of MSDs is essential for early identification of occupational hazards and to prevent health consequences and costs associated with absenteeism.

Inter- and intra-rater agreement of static posture analysis using a mobile application

[Purpose] To determine the intra- and inter-rater agreement of a mobile application, PostureScreen Mobile^® (PSM), that assesses static standing posture. [Subjects and Methods] Three examiners with different levels of experience of assessing posture, one licensed physical therapist and two untrained undergraduate students, performed repeated postural assessments of 10 subjects, fully clothed or minimally clothed, using PSM on two nonconsecutive days. Anterior and right lateral images were captured and seventeen landmarks were identified on them. Intraclass correlation coefficients (ICCs) were calculated for each of 13 postural measures to evaluate inter-rater agreement on the first visit (fully or minimally clothed), as well as intra-rater agreement between the first and second visits (minimally clothed). [Results] Eleven postural measures were ultimately analyzed for inter- and intra-rater agreement. Inter-rater agreement was almost perfect (ICC≥0.81) for four measures and substantial (0.60<ICC≤0.80) for three measures during the fully clothed exam. During the minimally clothed exam, inter-rater agreement was almost perfect for four measures and substantial for four measures. Intra-rater agreement between two minimally clothed exams was almost perfect for two measures and substantial for five measures. [Conclusion] PSM is a widely available, inexpensive postural screening tool that requires little formal training. To maximize inter- and intra-rater agreement, postural screening using this mobile application should be conducted with subjects wearing minimal clothing. Assessing static standing posture via PSM gives repeatable measures for anatomical landmarks that were found to have substantial or almost perfect agreement. Our data also suggest that this technology may also be useful for diagnosing forward head posture.

Low back pain functional disability in athletes; conceptualization and initial development of a questionnaire

Background:

Low Back Pain (LBP) is one of the most prevalent causes of disability not only in the general population but also in athletes. Despite a large number of self-reported back specific disability questionnaires, there is no specific, well documented, outcome measure for athletes suffering from back pain.

Objectives:

This study aimed to identify the main descriptive themes representing functional disability in athletes due to LBP.

Patients and Methods:

We conducted a qualitative study using in-depth interviews to characterize the experiences of athletes with LBP. Twenty athletes with LBP were recruited and the main descriptive elements of their LBP related disability were extracted. Then a preliminary questionnaire using these themes was proposed.

Results:

The main disability indicators were pain intensity; stretching exercises, strengthening exercises, sport specific skills, back range of motion (ROM), sitting, walking, sleep patterns, self-care, and recreational activities, fear of pain and avoidance behavior, and changes in sexual activity.

Conclusions:

The findings of this study suggest that apart from non-sports items, some sport related items should be included in the assessment of LBP disability levels in athletes. Our results have also been organized as a preliminary LBP disability questionnaire for athletes.

Prevalence of pain reporting and associated health outcomes across emerging markets and developed countries

OBJECTIVE

The current study represents the first broad, multi-country, population-based survey of pain, assessing the association between pain and health outcomes, plus comparing the burden of pain across emerging and developed countries.

DESIGN

Data from the 2011/2012 National Health and Wellness Surveys were used. Respondents reporting pain (neuropathic pain, fibromyalgia, back pain, surgery pain, and/or arthritis pain) vs no pain in emerging (Brazil, China, Russia) vs developed (European Union, Japan, United States) countries were compared on sociodemographic characteristics and measures of quality of life (SF-12v2 and SF-36v2), work productivity and activity impairment, and health care resource use.

SUBJECTS

Respondents included 128,821 without pain and 29,848 with pain in developed countries, and 37,244 without pain and 4,789 with pain in emerging countries.

RESULTS

Pain reporting and treatment rates were lower in China (6.2% and 28.3%, respectively) and Japan (4.4% and 26.3%, respectively) than in other countries (≥ 14.3% and 35.8%, respectively). Significant impairments in quality of life, productivity, and resource use were associated with pain across all health outcomes in both developed and emerging countries, with some productivity and physical health status impairments greater with pain in developed countries, whereas mental health status impairment and resource use were greater with pain in emerging countries.

CONCLUSIONS

Pain was associated with burden across all study outcomes in all regions. Yet, differences emerged in the degree of impairment, pain reporting, diagnosis, treatment rates, and characteristics of patients between emerging and developed nations, thus helping guide a broader understanding of this highly prevalent condition globally.

Low back pain beliefs are associated to age, location of work, education and pain-related disability in Chinese healthcare professionals working in China: a cross sectional survey

Background

Low back pain (LBP) is the leading cause of disability worldwide. Evidence pointing towards a more efficacious model of care using a biopsychosocial approach for LBP management highlights the need to understand the pain-related beliefs of patients and those who treat them. The beliefs held by healthcare professionals (HCPs) are known to influence the treatment advice given to patients and consequently management outcomes. Back pain beliefs are known to be influenced by factors such as culture, education, health literacy, place of work, personal experience of LBP and the sequelae of LBP such as disability. There is currently a knowledge gap among these relationships in non-western countries. The aim of this study was to examine the associations between LBP-related beliefs among Chinese HCPs and characteristics of these HCPs.

Methods

A convenience sample of 432 HCPs working in various health settings in Shanghai, China, completed a series of questionnaires assessing their demographic characteristics, LBP status, pain-related disability and their beliefs about their own LBP experience, using the Back beliefs Questionnaire (BBQ) and the Fear Avoidance Beliefs Questionnaire (FABQ).

Results

Younger Chinese HCPs (20–29 years) held more negative beliefs and attitudes related to LBP compared to older HCPs (>40years; BBQ mean difference [95% CI]: 2.4 [0.9 - 3.9], p = 0.001). HCPs working outside tertiary hospitals had poorer beliefs concerning the inevitable consequences of LBP (BBQ mean difference [95% CI]: −2.4 [−3.8 - −1.0], p = 0.001). HCPs who experienced LBP had higher level of fear avoidance beliefs when experiencing high LBP-related disability (FABQ-physical mean difference [95% CI]: 2.8 [1.5 - 4.1], p < 0.001; FABQ-work mean difference [95% CI]: 6.2 [4.0 - 8.4], p < 0.001)) and had lower level of fear avoidance beliefs if they had completed postgraduate study (FABQ-physical mean difference [95% CI]: 2.9 [−5.8 - 0.0], p = 0.049).

Conclusion

This study suggests that LBP-related beliefs and attitudes among Chinese HCPs are influenced by age, location of work, level of LBP-related disability and education level. Understanding back pain beliefs of Chinese HCPs forms an important foundation for future studies into the condition and its management in China.

The global burden of occupationally related low back pain: estimates from the Global Burden of Disease 2010 study

OBJECTIVES

The study was part of the Global Burden of Disease 2010 study and aimed to quantify the burden arising from low back pain (LBP) due to occupational exposure to ergonomic risk factors.

METHODS

Exposure prevalence was based on occupation distribution; estimates of relative risk came from a meta-analysis of relevant published literature. The work-related burden was estimated as disability-adjusted life years (DALYs). Estimates were made for each of 21 world regions and 187 countries, separately for 1990 and 2010 using consistent methods.

RESULTS

Worldwide, LBP arising from ergonomic exposures at work was estimated to cause 21.7 million DALYs in 2010. The overall population attributable fraction was 26%, varying considerably with age, sex and region. 62% of LBP DALYs were in males-the largest numbers were in persons aged 35-55 years. The highest relative risk (3.7) was in the agricultural sector. The largest number of DALYs occurred in East Asia and South Asia, but on a per capita basis the biggest burden was in Oceania. There was a 22% increase in overall LBP DALYs arising from occupational exposures between 1990 and 2010 due to population growth; rates dropped by 14% over the same period.

CONCLUSIONS

LBP arising from ergonomic exposures at work is an important cause of disability. There is a need for improved information on exposure distributions and relative risks, particularly in developing countries.

Differences between two subgroups of low back pain patients in lumbopelvic rotation and symmetry in the erector spinae and hamstring muscles during trunk flexion when standing

The present study was performed to examine lumbopelvic rotation and to identify asymmetry of the erector spinae and hamstring muscles in people with and without low back pain (LBP). The control group included 16 healthy subjects, the lumbar-flexion-rotation syndrome LBP group included 17 subjects, and the lumbar-extension-rotation syndrome LBP group included 14 subjects. Kinematic parameters were recorded using a 3D motion-capture system, and electromyography parameters were measured using a Noraxon TeleMyo 2400T. The two LBP subgroups showed significantly more lumbopelvic rotation during trunk flexion in standing than did the control group. The muscle activity and flexion-relaxation ratio asymmetries of the erector spinae muscles in the lumbar-flexion-rotation syndrome LBP group were significantly greater than those in the control group, and the muscle activity and flexion-relaxation ratio asymmetry of the hamstring muscles in the lumbar-extension-rotation syndrome LBP group were significantly greater than those in the control group. Imbalance or asymmetry of passive tissue could lead to asymmetry of muscular activation. Muscle imbalance can cause asymmetrical alignment or movements such as unexpected rotation. The results showed a greater increase in lumbopelvic rotation during trunk flexion in standing among the lumbar-flexion-rotation syndrome and lumbar-extension-rotation syndrome LBP groups compared with the control group. The differences between the two LBP subgroups may be a result of imbalance and asymmetry in erector spinae and hamstring muscle properties.

Back and neck pain due to working in a cold environment: a cross-sectional study of male construction workers

OBJECTIVE

To study whether work in a cold environment increased the risk of musculoskeletal symptoms in the neck and low back among construction workers.

METHODS

This cross-sectional study is based on a cohort of male workers in the Swedish construction industry that participated in regular health examinations through a nationwide occupational health service. The analysis is based on workers examined from 1971 to 1974, who answered a questionnaire including questions about neck and back pain. The cohort consists of 134,754 male workers, including 16,496 office workers and foremen. The health examinations of the workers were conducted in provinces covering Sweden from the south to the north, and temperature data were collected for the provinces. In the analyses, the results were adjusted for age, BMI and use of nicotine.

RESULTS

The prevalence's of neck and low back pain were higher among manual construction workers than among foremen and office workers (24.3 vs. 8.6 % and 16.5 vs. 6.2 %, respectively); the corresponding adjusted ORs for low back and neck pain were 1.59 (95 % CI 1.52-1.66) and 1.39 (95 % CI 1.30-1.49), respectively. Workers in the northern and central provinces had higher ORs for low back and neck pain compared to workers in the southern province. The test for trends showed an increased risk of developing low back and neck pain with decreased outdoor temperature.

CONCLUSIONS

Outdoor work in a cold environment may increase the risk of low back and neck pain.

Influence of automobile seat lumbar support prominence on spine and pelvic postures: a radiological investigation

BACKGROUND

The use of lumbar supports has been associated with decreased reports of low back pain during driving exposures. However, there has been limited work investigating whether lumbar supports actually change spine and pelvic postures at the level of the vertebrae.

PURPOSE

To investigate the effectiveness of a lumbar support in changing radiological measures of lumbar spine and pelvic postures and to examine the impact of support excursion magnitudes on these postures.

METHODS

Eight male subjects were recruited with no history of back injury, pathologies or low back pain within the past 6 months. Radiographs were taken in four postures: standing, and sitting with 0 cm, 2 cm and 4 cm lumbar support prominence (LSP).

RESULTS

Lumbar lordosis angle increased from 20° with no support to 25° with 2 cm support and 30° with 4 cm support. Lumbar lordosis angles were significantly different between 0 cm support and 4 cm support (p < 0.0001) and between 2 cm support and 4 cm support (p = 0.0256). Increasing lumbar support reduced the flexion at intervertebral disc joints throughout the lumbar spine, however, these remained significantly different from upright standing (p > 0.001) with the exception of L1/L2 in 4 cm support (p = 0.1381) and L5/S1 for all seated postures (p = 0.0687). All measures of pelvic posture were significantly different in sitting compared to standing (p < 0.0001), however, the lumbar support had no significant impact on seated pelvic posture.

CONCLUSIONS

Lumbar supports were shown to impact the vertebral rotations of the lumbar spine yet had no effect on pelvis postures. Increasing support from the current maximum of 2 cm-4 cm resulted in increased lumbar lordosis. The changes were mostly imparted at the upper lumbar spine joints with the most marked change being exhibited at the approximate level of the lumbar support apex: in the L2/L3 joint.

Validation of the simplified chinese version of the functional rating index for patients with low back pain

STUDY DESIGN

Cross-cultural translation and psychometric testing of the functional rating index (FRI).

OBJECTIVE

To evaluate the reliability and validity of the adapted simplified Chinese FRI (SC-FRI) for patients with low back pain (LBP).

SUMMARY OF BACKGROUND DATA

The FRI is a reliable and valid instrument to assess the perception of function and pain for patients with LBP. However, there is no culturally adapted, reliable, and validated FRI for use in mainland China.

METHODS

The translation and cross-cultural adaptation were performed following international guidelines. The SC-FRI was administered to 115 patients with LBP along with the simplified Chinese version of the Oswestry disability index, 36-item short form health survey, and the visual analogue scale. Psychometric testing included internal consistency, test-test reliability, concurrent criterion validity, and construct validity.

RESULTS

A high completion rate of 96% and no floor or ceiling effects were noted for the SC-FRI. The internal consistency was good (i.e., Cronbach α = 0.897 for the overall SC-FRI; range, 0.851-0.890, if an item was deleted). Test-retest reliability was excellent, with an intraclass correlation coefficient of 0.948 (95% confidence interval, 0.917-0.968). Concurrent criterion validity assessment demonstrated that the SC-FRI significantly correlated with the visual analogue scale (r = 0.852, P < 0.0001) and the simplified Chinese version of the Oswestry disability index (r = 0.958, P < 0.0001). Construct validity was confirmed by the significant Pearson correlation between the SC-FRI and physical functioning (r = -0.802, P < 0.0001), Bodily Pain (r = -0.698, P < 0.0001), social functioning (r = -0.573, P < 0.0001), role-physical (r = -0.503, P < 0.0001), and general health (r = -0.502, P < 0.0001) domains of the 36-Item Short Form Health Survey.

CONCLUSION

The SC-FRI showed excellent reliability and validity in the evaluation of pain and the functional health status of Chinese-speaking patients with LBP. It is simple and easy to use and can be recommended in clinical and research practice in mainland China.

Prevalence and work-related risk factors for reduced activities and absenteeism due to low back symptoms

Although quite a lot is known about the risk factors for low back symptoms (LBS), less is known about the risk factors for the consequences of LBS. A sample of 3003 men and women randomly selected from the New Zealand Electoral Roll, were interviewed by telephone about self reported physical, psychosocial, organizational, environmental factors and the consequences of LBS (i.e. self-reported reduced activities and absenteeism). The 12-month period prevalence of reduced activities and absenteeism were 18% and 9%, respectively. Lifting (OR 1.79 95% CI 1.16-2.77) increased the risk of reduced activities. Working in awkward/tiring positions (OR 2.11 95% CI 1.20-3.70) and in a cold/damp environment (OR 2.18 95% CI 1.11-4.28) increased the risk of absenteeism. Among those with LBS, reduced activities increased with working in a hot/warm environment (OR 2.14 95% CI 1.22-3.76) and absenteeism was increased with work in awkward/tiring positions (OR 2.06 95% CI 1.13-3.77), tight deadlines (OR 1.89 95% CI 1.02-3.50), and a hot/warm environment (OR 3.35 95% CI 1.68-6.68). Interventions to reduce the consequences of LBS should aim to reduce awkward/tiring positions, lifting and work in a cold/damp environment. For individuals with LBS, additional focus should be to reduce tight deadlines, and work in hot/warm environments.

Cross-cultural adaptation and validation of simplified Chinese version of the Roland-Morris Disability Questionnaire

STUDY DESIGN

The Roland-Morris Disability Questionnaire (RMDQ) was translated and then adapted and validated.

OBJECTIVE

Translation of the RMDQ into simplified Chinese characters (SCRMDQ), and its cross-cultural adaptation and validation in patients with low back pain with or without radicular leg pain.

SUMMARY OF BACKGROUND DATA

The RMDQ is used worldwide and versions in traditional Chinese characters are available in Hong Kong and Taiwan. But there is no version in simplified Chinese characters for use in Mainland China.

METHODS

The original version of the RMDQ was translated and back-translated, and then cross-cultural adaptation of the simplified Chinese version was performed following published guidelines. The SCRMDQ was validated in 150 patients, 30 of whom finished the prefinal SCRMDQ and helped determine the final version. The remaining 120 patients were asked to complete the final SCRMDQ, simplified Chinese Oswestry Disability Index (SCODI), and visual analogue scale. Reliability was assessed with the final version using internal consistency by the Cronbach α coefficient and intraclass correlation coefficient; structural validity was evaluated by correspondence analysis. Then comparison of SCRMDQ and SCODI was performed.

RESULTS

A total of 116 patients in the final validation study finished the questionnaires completely. Their mean age was 52.17 ± 11.95 years (range, 22-78 yr) and the mean low back pain duration was 42.04 ± 60.94 months (range, 2-480 mo). The average time taken was 4.11 ± 1.48 minutes (range, 2-9 min) on SCRMDQ and 7.37 ± 3.98 minutes (range, 3-30 min) on SCODI. The mean SCRMDQ, SCODI, and visual analogue scale scores were 14.07 ± 4.79 (range, 2-24), 23.98 ± 10.38 (range, 2-47), and 57.17 ± 20.72 (range, 0-95), respectively. In the final test, the Cronbach α for internal consistency was 0.826 and intraclass correlation coefficient was 0.947; both showed adequate acceptance. Positive and statistically significant correlations were found between SCRMDQ and SCODI (r = 0.791, P < 0.01) and visual analogue scale (r = 0.493, P < 0.01), indicating sufficient structural validation. Most patients preferred SCRMDQ to SCODI, because it was simpler to understand and easier to finish.

CONCLUSION

The SCRMDQ was reliable and valid as a low back pain measurement tool in patients with or without radicular leg pain in Mainland China. The further use and research with the questionnaire were recommended.

Reliability and validity of simplified Chinese version of Roland-Morris questionnaire in evaluating rural and urban patients with low back pain

Objective

The causes of low back pain in China and Western countries are extremely different. We attempted to analyze the risk factors of low back pain in urban and rural patients under the dual economy with the simplified Chinese version of Roland-Morris disability questionnaire (SC-RMDQ) to demonstrate that SC-RMDQ could evaluate patients with low back pain arising from different causes.

Methods

Roland-Morris disability questionnaire was translated into SCRMDQ according to international guidelines for questionnaire adaptation. In this study, causes of low back pain of 187 outpatients and inpatients (99 urban patients and 88 rural patients) were analyzed. All patients underwent simplified Chinese version of Roland-Morris disability questionnaire (SC-RMDQ), simplified Chinese Oswestry disability index (SCODI) and visual analogue scale (VAS). Reliability was tested using reproducibility (intraclass coefficient of correlation – ICC) and internal consistency (Cronbach's alpha). Validity was tested using Pearson correlation analysis.

Results

The leading causes for low back pain were sedentariness (38.4%) and vibration (18.1%) in urban patients and waist bending (48.9%) and spraining (25%) in rural patients. Although causes of low back pain in the two groups of population were completely different, SCRMDQ had high internal consistency (Cronbach's α value of 0.874 in urban patients and 0.883 in rural patients) and good reproducibility (ICC value of .952 in urban patients and 0.949 in rural patients, P<0.01). SCRMDQ also showed significant correlation with Simplified Chinese version of Oswestry disability index (SCODI) and visual analogue scale (VAS) in rural areas (SCRMDQ-SCODI r = 0.841; SCRMDQ -VAS: r = 0.685, P<0.01) and in urban areas (SCRMDQ-SCODI: r = 0.818, P<0.01; SCRMDQ –VAS: r = 0.666, P<0.01).

Conclusions

Although causes of low back pain are completely different in rural and urban patients, SCRMDQ has a good reliability and validity, which is a reliable clinical method to evaluate disability of rural and urban patients.

The role of past and current strenuous physical work in the association between professional car driving and chronic low-back syndromes: a population-based study

STUDY DESIGN

Population-based cross-sectional study of clinically assessed low back syndromes.

OBJECTIVE

To investigate whether exposure to professional car driving, either alone or in combination with strenuous physical work is associated with clinically defined sciatica or other clinically diagnosed chronic low back syndromes.

SUMMARY OF BACKGROUND DATA

Several studies have found an association between professional driving and back disorders, but drivers' histories of heavy physical work tasks has rarely been taken into account.

METHODS

The nationally representative sample comprised of 2323 men aged 30 to 64 (the Health 2000 Survey). The diagnoses of sciatica and chronic low back syndromes were based on a standardized clinical examination by specially trained physicians. Life-long exposure to professional car driving and to physically demanding work was assessed retrospectively via interviews. Logistic regression was used to estimate the risk of clinical chronic low back syndromes related to these exposures, and the risks were presented with odds ratios (OR) with 95% confidence intervals (95% CI).

RESULTS

The prevalence of physician-diagnosed sciatica was 5.4% and that of other chronic low back syndromes 4.0%. Professional car driving in general was associated with sciatica at an OR of 1.42 (95% CI 0.92-2.18) and with other chronic low back syndromes at an OR of 1.31 (0.80-2.16), after adjustment of covariates and strenuous physical work. Exposure to driving without exposure to physical work was not associated with the outcomes, whereas driving in combination with strenuous physical work increased the risk for sciatica threefold (3.22; 1.86-5.59), and that of low back syndromes twofold (2.08; 1.12-3.87).

CONCLUSION

The increased risk of low back disorders related to professional car driving is more likely due to strenuous work tasks rather than to driving itself.

Cross-cultural adaptation, reliability and validity of the Chinese version of the Fear Avoidance Beliefs Questionnaire

The Fear Avoidance Beliefs Questionnaire (FABQ) was translated and cross-culturally adapted for China. Its psychometric properties were then evaluated in Chinese-speaking patients with low-back pain and the scales were tested for internal consistency, reproducibility, ceiling-and-floor effects, construct validity and responsiveness. A total of 15 patients were selected for pre-testing and a further 230 patients completed the FABQ (and other scales) at baseline and 14 days later. A test-retest reliability analysis was carried out on 61 of the 230 patients. The FABQ was found to be easily understood. Explorative factor analysis by principal components analysis, yielded a two-factor model for the FABQ, relating to work and physical activity, and this was confirmed by confirmatory factor analysis using structural equation modelling. The FABQ yielded high values for internal consistency and reproducibility; no ceiling-and-floor effects were detected. Generally, the FABQ scales and baseline variables were weakly correlated. Cohen's effect size was 0.22 and responsiveness was low. It was concluded that the translation and adaptation of the FABQ into Chinese was successful; the scales had acceptable factor structure, internal consistency, test-retest reliability and construct validity.

Responsiveness of the Chinese version of the Oswestry disability index in patients with chronic low back pain

The Oswestry Disability Index (ODI) is one of the most widely used questionnaires that assess disability in patients with low back pain (LBP). Responsiveness is both an important psychometric property of an instrument and a key issue for clinicians when choosing suitable outcome measures. The objective of this study was to examine the responsiveness of the Chinese version of the ODI (ODI-Chinese) for subjects with chronic LBP following a physical therapy program. In total, 76 patients with chronic LBP completed the ODI-Chinese, a visual analog scale (VAS) of pain, and the Chinese version of Short Form-36 (SF-36) before and after treatment. All patients also completed a global perception of change Likert scale in condition after the program. The scale was collapsed to produce a dichotomous variable outcome, improved or non-improved. The responsiveness of the instruments was determined using the standardized response means (SRM) and receiver operating characteristics (ROC). After treatment, 56 patients considered themselves to be improved. The SRM of the ODI-Chinese was -1.2 in the improved group and -0.4 in the non-improved group. The area of the ROC curve for the ODI-Chinese was 0.77 (95% CI 0.66-0.89). Therefore, the Chinese version of the ODI is both responsive and appropriate for use in chronic LBP patients after conservative therapy.

Factors associated with self-estimated work ability and musculoskeletal symptoms among male and female workers in cooled food-processing facilities

This questionnaire study evaluates how work ability and musculoskeletal symptoms associate with physical work factors and individual characteristics of the workers in cooled food-processing facilities. A total of 1,117 workers (response rate 85%) responded to the study. Poor work ability was significantly associated with longer work duration, experience of draught at the workplace, absence from work due to health reasons, and physical inactivity during free time. The amount of local cooling experienced was significantly associated with the risk for musculoskeletal symptoms in the neck-shoulder region, shoulders, wrists and lower back. Additionally, female gender, longer work duration and poor work ability were associated with the increased prevalence of the symptoms. The prevalence of musculoskeletal symptoms was significantly higher among older employees (40 to 64 yr) than among younger employees (18 to 39 yr) for all regions except wrists. Cold discomfort and unpleasant sensations due to the physical factors of work were significantly more common among females than males. The results showed that, in addition to individual characteristics of workers, factors related to work in a cool environment (experience of draught and cooling and long exposure to cold) are associated with poor work ability and musculoskeletal symptoms.

Health problems in cold work

Cold in- and outdoor work can result in different adverse effects on human health. Health problems decrease performance and work productivity and increase the occurrence of accidents and injuries. Serious health problems can also result in absence from work due to sick leave or hospitalization. At its worst, work in cold conditions could be associated with deaths due to cold-related accidents or a sudden health event. Musculoskeletal complaints, like pain, aches etc. are common in indoor cold work. Breathing cold air while working may lead to respiratory symptoms, which can decrease performance in cold. The symptoms are usually worsened by exercise and ageing, being more common in persons having a respiratory disease. Cardiovascular complaints and related performance decrements could be especially pronounced during work in cold weather and involving physical exercise, especially among those with an underlying cardiovascular disease. The article also reviews the current information related to diabetes, skin disorders and diseases, as well as cold injuries and accidents occurring in cold work. Increasing awareness and identifying workplace- and individual-related cold risks is the first step in proper cold risk management. Following this, the susceptible population groups need customized advice on proper prevention and protection in cold work.

Validation of the simplified Chinese version of the Oswestry Disability Index

STUDY DESIGN

Translation, cross-cultural adaptation, and validation were performed on the Chinese version of the Oswestry Disability Index (ODI).

OBJECTIVE

The objective of this study was to translate and adapt the ODI into simplified Chinese and to then validate its use in Chinese patients with low back pain.

SUMMARY OF BACKGROUND DATA

A traditional Chinese version of the ODI (TCODI) has been developed and used in Hong Kong. However, there is no simplified Chinese version of the ODI (SCODI).

METHODS

Translation and cross-cultural adaptation of the latest version of the ODI (2.1a) were performed following instructions from the published international guidelines. The translation procedure included forward translation, back translation, and a discussion among experts. The prefinal version was tested in 40 outpatients with LBP. Then, 179 patients with LBP, including 140 outpatients and 39 inpatients, participated in the final test. They finished the SCODI, the Short-Form 36, and the Visual Analog Scale. Those 39 inpatients also finished a second ODI questionnaire within 24 hours. Last, the SCODI and TCODI were tested in another 25 inpatients for comparison.

RESULTS

All of the patients in the prefinal test understood the simplified Chinese version correctly. In the final test, Cronbach's alpha for internal consistency was 0.93. A very high intraclass correlation coefficient was observed (ICC = 0.99) in the test-retest group. The SCODI showed a significant correlation with the 8 subscales of the Short-Form 36, especially in physical functioning (r = 0.78, P < 0.001). There was a moderate correlation between the ODI scores and the Visual Analog Scale (r = 0.69, P < 0.001). A significant difference in the mean score was demonstrated between the SCODI and the TCODI. Patients who participated in the comparison test all agreed that the SCODI was easier to understand than the TCODI.

CONCLUSION

The results showed that the translation and adaptation were successful. The SCODI has proven to be valid and reliable when used in the simplified Chinese speaking population.

City bus driving and low back pain: a study of the exposures to posture demands, manual materials handling and whole-body vibration

A cross-sectional study was conducted to investigate worker exposure to posture demands, manual materials handling (MMH) and whole body vibration as risks for low back pain (LBP). Using validated questionnaire, information about driving experience, driving (sitting) posture MMH, and health history was obtained from 80 city bus drivers. Twelve drivers were observed during their service route driving (at least one complete round trip) and vibration measurements were obtained at the seat and according to the recommendations of ISO 2631 (1997), for three models of bus (a mini-bus, a single-decker bus, a double-decker bus). The results showed that city bus drivers spend about 60% of the daily work time actually driving, often with the torso straight or unsupported, perform occasional and light MMH, and experience discomforting shock/jerking vibration events. Transient and mild LBP (not likely to interfere with work or customary levels of activity) was found to be prevalent among the drivers and a need for ergonomic evaluation of the drivers' seat was suggested.

Estimating the global burden of low back pain attributable to combined occupational exposures

BACKGROUND

There is little information about the global burden of non-traumatic low back pain (LBP) attributable to the effects of physical and psychosocial occupational stressors.

METHODS

Based on a review of the epidemiological evidence, occupation-specific relative risks were used to compute attributable proportions by age, gender, and geographical sub-region for the economically active population aged 15 and older. The reference group was professional/administrative workers; other risk categories were Low, clerical and sales; Moderate, operators (production workers) and service; and High, farmers.

RESULTS

Worldwide, 37% of LBP was attributed to occupation, with twofold variation across regions. The attributable proportion was higher for men than women, because of higher participation in the labor force and in occupations with heavy lifting or whole-body vibration. Work-related LBP was estimated to cause 818,000 disability-adjusted life years lost annually.

CONCLUSIONS

Occupational exposures to ergonomic stressors represent a substantial source of preventable back pain. Specific research on children is needed to quantify the global burden of disease due to child labor.

Low back pain risk factors in a large rural Australian Aboriginal community. An opportunity for managing co-morbidities?

BACKGROUND

Low back pain (LBP) is the most prevalent musculo-skeletal condition in rural and remote Australian Aboriginal communities. Smoking, physical inactivity and obesity are also prevalent amongst Indigenous people contributing to lifestyle diseases and concurrently to the high burden of low back pain.

OBJECTIVES

This paper aims to examine the association between LBP and modifiable risk factors in a large rural Indigenous community as a basis for informing a musculo-skeletal and related health promotion program.

METHODS

A community Advisory Group (CAG) comprising Elders, Aboriginal Health Workers, academics, nurses, a general practitioner and chiropractors assisted in the development of measures to assess self-reported musculo-skeletal conditions including LBP risk factors. The Kempsey survey included a community-based survey administered by Aboriginal Health Workers followed by a clinical assessment conducted by chiropractors.

RESULTS

Age and gender characteristics of this Indigenous sample (n = 189) were comparable to those reported in previous Australian Bureau of Statistics (ABS) studies of the broader Indigenous population. A history of traumatic events was highly prevalent in the community, as were occupational risk factors. Thirty-four percent of participants reported a previous history of LBP. Sporting injuries were associated with multiple musculo-skeletal conditions, including LBP. Those reporting high levels of pain were often overweight or obese and obesity was associated with self-reported low back strain. Common barriers to medical management of LBP included an attitude of being able to cope with pain, poor health, and the lack of affordable and appropriate health care services. Though many of the modifiable risk factors known to be associated with LBP were highly prevalent in this study, none of these were statistically associated with LBP.

CONCLUSION

Addressing particular modifiable risk factors associated with LBP such as smoking, physical inactivity and obesity may also present a wider opportunity to prevent and manage the high burden of illness imposed by co-morbidities such as heart disease and type-2 diabetes.

Musculoskeletal disorders among Chinese medical students

We investigated the prevalence and distribution of Musculoskeletal Disorders (MSD) among Chinese medical students, by means of a questionnaire survey. A total of 207 questionnaires were successfully returned, giving a high response rate of 92.4%. The MSD period-prevalence at any body site was 67.6% in the previous year and 46.9% in the previous week. Almost one-third of them (31.9%), reported an ongoing MSD. By individual body site, the most commonly affected region was the lower back (40.1% in the last year), followed by the neck (33.8%) and shoulders (21.7%). The 7 day period-prevalence also followed a similar descending pattern, being reported by 20.8% at the lower back and 12.1% at both the neck and knees. MSD affected the daily life of students for an average period of 53.8 days, with an average of 6.6 sick days taken from school. Students reporting high mental pressure were 2.9 times more likely to suffer low back pain in the previous 12 months (OR 2.9, 95%CI 1.4-5.9, P=0.0030). Overall, our study suggests that Chinese medical students are at reasonable MSD risk, although it is probably lower than for working physicians. Further investigations are now recommended to elucidate the MSD mechanisms and contributory factors among medical students in China, as elsewhere. A longitudinal study of MSD among a complete group of medical students would be very useful in this regard.

Effects of low back pain on the relationship between the movements of the lumbar spine and hip

Previous research had examined the effects of back pain on spinal movements, but information concerning movement coordination between the lumbar spine and hips was limited. The purpose of this study was to examine the effects of back pain and limitation in straight leg raise on the relationship between the movements of the lumbar spine and hip. An electromagnetic tracking system was employed to measure the movements of these joints in asymptomatic subjects (n = 20), and back pain subjects with (n = 24) and without (n = 17) limitation in straight leg raise. Subjects were requested to perform forward, backward and side bending, and twisting of the trunk. Back pain subjects were found to exhibit significant reductions in the magnitude of spine movements in all directions. Back pain was also associated with decrease in the magnitude of hip flexion but not hip movements in other directions. Cross-correlation analysis showed that there were changes in the strength of correlation and the time lag between lumbar spine and hip motions in normal and back pain subjects. In addition, back pain and limitation in straight leg raise were found to cause significant increases in the time required to complete the trunk movements. It was concluded that clinical assessment and treatment planning should take into account of the effects of back pain on the relationship between spine and hip movements.

Work-related musculoskeletal problems among women workers in the semiconductor industry in Peninsular Malaysia

A cross-sectional study to identify the prevalence of musculoskeletal problems and work-related risk factors was conducted among 906 women semiconductor workers. Highest prevalences were pain in the lower limbs, neck/shoulders, and upper back, and highest exposures were prolonged (> or = four hours per workshift) hand/wrist movement, standing, and lifting with hands. After logistic regression, lower-limb pain was significantly associated with standing, neck/shoulder pain with sitting and lifting, upper-back pain with climbing steps, low back pain with hand/wrist movement, and hand/wrist pain with lifting. Neck/shoulder pain was significantly higher for workers with shorter working durations, while lower-limb pain was significantly higher for workers with longer working durations. End-of-line assembly workers had significantly higher odds ratios for pain at all sites, while middle-of-line workers had higher odds ratios for pain in neck/shoulders and upper back, and wafer-fabrication workers had higher odds ratios for pain in low back and lower limbs.

Occupational health services in PR China

In China, the origin of occupational health started in the mid 1950s soon after the founding of the People's Republic of China. However, more complete concept and practice of occupational health was defined after the early 1980s, when China started her full-scale drive for economic reform and policy of openness. The integrity intends to cover occupational health, occupational medicine, industrial toxicology, industrial hygiene, occupational ergonomics, and occupational psychology as theoretical and practical components of occupational health. As a result, occupational health in China has undergone many changes and has improved over the past decades. These changes and improvements came about, most likely due to a new scheme, where a holistic approach of the recognition, regulation, and provision of occupational health services in a wider coverage is gradually formed and brought into effect. This presentation provides the current status of occupational health and safety problems, the latest legislative to occupational health and safety, and a general scenario of the organizational structure and function of occupational health services in China. It attempts to share with participants both our experience and lessons learned towards creating a more open and effective channel of ideas and information sharing.

Mechanical injury and psychosocial factors in the work place predict the onset of widespread body pain: A two-year prospective study among cohorts of newly employed workers

OBJECTIVE

Mechanical injury has been postulated as a risk factor for widespread pain, although to date, the evidence is weak. The aim of this study was to determine whether repeated exposure to mechanical trauma in the work place predicts the onset of widespread pain and to determine the relative contribution of mechanical trauma compared with psychosocial factors.

METHODS

In this prospective cohort study of 1,081 newly employed subjects in 12 diverse occupational settings, we collected detailed information on mechanical exposure, posture, physical environment, and psychosocial risk factors in the work place. Study questionnaires were completed at baseline and at 12 and 24 months. Individuals free of widespread pain at baseline and 12 months were eligible for followup. Generalized estimating equations were used to determine which factors predicted the new onset of widespread pain.

RESULTS

Of the 1,081 baseline respondents, 896 were free of widespread pain and were eligible for further study. Of these 896 subjects, 708 and 520 responded at 12 months and 24 months, respectively. The rates of new-onset widespread pain were 15% at 12 months and 12% at 24 months. Several work place mechanical and posture exposures predicted the new onset of widespread pain: lifting >15 lbs with 1 hand, lifting >24 lbs with 2 hands, pulling >56 lbs, prolonged squatting, and prolonged working with hands at or above shoulder level. Of the psychosocial exposures, those who reported low job satisfaction, low social support, and monotonous work had an increased risk of new-onset widespread pain. In multivariate analysis, monotonous work and low social support were found to be the strongest independent predictors of symptom onset.

CONCLUSION

Our findings demonstrate that the prevalence of new-onset widespread pain was high, but among this young, newly employed work force, both physical and psychosocial factors played an important role.

Prevalence of low back pain in three occupational groups in Shanghai, People's Republic of China

PROBLEM

Low back pain (LBP) is one of the most prevalent work-related conditions affecting employed populations in developed countries, yet little is known about this condition among the world's largest, single-nation labor force: The People's Republic of China.

METHOD

This is a cross-sectional study of the prevalence of low back pain (LBP) among garment workers, battery/kiln workers, and teachers in Shanghai, People's Republic of China. Data were collected by personal interview and physical examination at six work sites. The overall response rate was 78%.

RESULTS

The overall (N=383) self-reported annual prevalence of LBP symptoms lasting 24 hours or more was 50%. Garment workers had a higher annual prevalence of LBP (74%) than teachers (40%), prevalence ratio (PR=1.9, 95% CI=1.4-2.4).

DISCUSSION

The overall annual prevalence of self-reported LBP (50%) was higher than that reported among 50 other Chinese employed study populations (30%). Healthy worker effects may have limited the conclusions from this cross-sectional study.

SUMMARY

These results suggest that LBP is a prevalent condition in Chinese workers and that more work should be done to estimate its impact on the Chinese workforce. The findings for garment workers were consistent with increased risk of LBP among persons doing work in fixed, sedentary postures.

Relationship between the movements of the lumbar spine and hip

Movements of the lumbar spine and hips were measured in 20 healthy subjects using an electromagnetic tracking device. Movement sensors were attached to the L1 spinous process, the sacrum and the thighs. Each subject was requested to perform the following movements of the trunk: forward and backward bending, lateral bending and twisting. The ratio of the maximum magnitude of spine movement to that of the hip was determined. Angle-angle plot and cross-correlation were used to examine the relationship between the movements of the spine and hip. It was shown that during forward and backward bending of the trunk, the overall contributions of the lumbar spine and hip were similar, but the spine had a greater contribution to the early stage of the movement. Lateral bending of the trunk was found to be primarily accomplished by movement of the spine, whereas the hips were the predominate sources of movement for twisting. Moreover, it was shown that in the sagittal and horizontal planes, the movement patterns of the spine and hip were in phase, whereas in the coronal plane, the spine generally moved earlier than the hips. It is concluded that clinical examination of the back should include kinematic measures of both the lumbar spine and hips.