The influence of work-related exposures on the prognosis of neck/shoulder pain

Cardiovascular Disease Risk Factors Predict the Development and Numbers of Common Musculoskeletal Disorders in a Prospective Cohort

OBJECTIVE

The aim of the study is to assess risk of common musculoskeletal disorders (MSDs) based on cardiovascular disease (CVD) risk scores.

METHODS

Data from a 9-year prospective cohort of 1224 workers in three states were analyzed. Baseline data included questionnaires, structured interviews, physical examinations, anthropometric measurements, nerve conduction studies, and individualized measurement of job physical factors. Monthly follow-ups were conducted. Framingham risk scores were calculated. A priori case definitions were constructed for carpal tunnel syndrome, lateral epicondylopathy, medial epicondylopathy, and rotator cuff tendinopathy.

RESULTS

Adjusted RRs for one or more MSDs increased to 3.90 (95% confidence interval, 2.20-6.90) among those with 10-year cardiovascular disease risk scores greater than 15% and 17.4 (95% confidence interval, 3.85-78.62) among those with more than 4 disorders.

CONCLUSIONS

Cardiovascular disease factors are strongly associated with the subsequent development of common MSDs. Risks among those with multiple MSDs are considerably stronger.

Are respiratory disorders risk factors for troublesome neck/shoulder pain? A study of a general population cohort in Sweden

PURPOSE

The etiology of neck/shoulder pain is complex. Our purpose was to investigate if respiratory disorders are risk factors for troublesome neck/shoulder pain in people with no or occasional neck/shoulder pain.

METHODS

This prospective cohort study was based on the Stockholm Public Health Cohorts (SPHC) 2006/2010 and the SPHC 2010/2014. We included adults who at baseline reported no or occasional neck/shoulder pain in the last six months, from the two subsamples (SPHC 06/10 n = 15 155: and SPHC 2010/14 n = 25 273). Exposures were self-reported asthma at baseline in SPHC 06/10 and Chronic Obstructive Pulmonary Disease (COPD) at baseline in SPHC 10/14. The outcome was having experienced at least one period of troublesome neck/shoulder pain which restricted work capacity or hindered daily activities to some or to a high degree during the past six months, asked for four years later. Binomial regression analyses were used to calculate risk ratios (RR) with 95% confidence intervals (95% CI).

RESULTS

Adjusted results indicate that those reporting to suffer from asthma at baseline had a higher risk of troublesome neck/shoulder pain at follow-up four years later (RR 1.48, 95% CI 1.10-2.01) as did those reporting to suffer from COPD (RR 2.12 95%CI 1.54-2.93).

CONCLUSION

Our findings indicate that those with no or occasional neck/shoulder pain and reporting to suffer from asthma or COPD increase the risk for troublesome neck/shoulder pain over time. This highlights the importance of taking a multi-morbidity perspective into consideration in health care. Future longitudinal studies are needed to confirm our findings.

The Correlation of Frequency of Work-Related Disorders with Type of Work among Polish Employees

Musculoskeletal disorders have a significant negative impact on the quality of life of the population. These conditions, as well as other work-related disorders, generate costs associated with treatment and work absence, which makes it a growing problem in industrialized countries. Available data from studies on individual populations of workers indicate a higher incidence of certain symptoms in these groups. Due to the lack of studies on the general population, we aimed to perform the preliminary study evaluating the occurrence of pain and work-related conditions depending on the type of occupational work among Polish employees to identify further possible areas for research. Data was collected using an electronic self-administered questionnaire, which was distributed in groups bringing together various professionals. The data obtained from 379 participants have been analyzed and divided according to performed work into sedentary, forced posture, standing, physical and requiring physical activity. Our study reveals a correlation between the frequency of work-related disorders and type of work performed in the Polish population. A significant correlation between the type of occupational work and prevalence of ankle, knee and shoulder pain, as well as heavy legs or upper limb paresthesia was found. According to our findings, female employees may be more vulnerable to lower limb symptoms. A place of residence also seems to affect the prevalence of upper back pain and heavy legs. The analysis also showed a correlation between the occurrence of hip, knee and ankle pain and the level of education of the participants. Surprisingly, lower extremity paresthesia was significantly more common among participants undertaking additional physical activity, compared to non-physically active respondents.

Association between working in awkward postures, in particular overhead work, and pain in the shoulder region in the context of the 2018 BIBB/BAuA Employment Survey

Background

Musculoskeletal disorders are the leading cause of work-related sick leave and incur substantial socioeconomic costs. With the aging of our society and employees, the problem is exacerbating, and prevention is becoming increasingly important. According to previous studies, exposure to awkward postures, such as overhead work, is associated with musculoskeletal problems.

Objective

This study aimed to determine the current prevalence of employees who work in awkward postures, specifically overhead, stratified by age, gender and occupation in the context of the 2018 BIBB/BAuA Employment Survey and to analyze associations between awkward working postures, in particular overhead work, and pain in the shoulder region.

Method

The study is based on secondary data from the German 2018 BIBB/BAuA Employment Survey. We have included 14,327 of the 20,012 employees aged < 67 years who work at least 35 h per week who took part in the survey. The classification of participants in occupational groups is based on the Blossfeld classification. The multivariate analysis was conducted by applying robust Poisson regression models adjusted block by block to obtain the relation between the self-reported frequency of working in awkward postures, in particular overhead work, and the occurrence of arm pain and neck and shoulder pain. Prevalence ratios (PR) are reported as effect estimates.

Results

12.7% of participants indicated that they are often exposed to awkward postures at work; 5.0% stated they often performed overhead work. The majority of these employees worked in agricultural, unskilled and skilled manual occupations. The crude prevalence is 17.4% for arm pain and 48.4% for neck and shoulder pain. If subjects reported that they often performed overhead work, the risk of arm pain increased by 18% (PR 1.18, CI 1.04–1.34, final model).

Conclusion

Working in awkward postures, especially overhead work, is a risk factor for upper extremity musculoskeletal disorders. The development of prevention strategies should focus on the workforce in agricultural, unskilled and skilled manual occupations.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-021-04482-4.

Larger pain extent is associated with greater pain intensity and disability but not with general health status or psychosocial features in patients with cervical radiculopathy

Pain as a result of cervical radiculopathy (CR) can be widespread, nondermatomal and individually specific, but the association between pain extent and other clinical features has never been explored. The objective of this study is to investigate whether pain extent relates to clinical variables including pain intensity in addition to health indicators including disability, general health, depression, somatic anxiety, coping strategies or self-efficacy.An observational cohort study was conducted. Participants were recruited from 4 hospital spinal centres in Sweden. Pain extent was quantified from the pain drawings of 190 individuals with cervical disc disease, verified with magnetic resonance imaging (MRI) and compatible with clinical findings (examined by a neurosurgeon), that show cervical nerve root compression. Pain extent was evaluated in relation to neck pain, arm pain, and headache intensity. Multiple linear regression analysis were then used to verify whether pain extent was associated with other health indicators including disability, health-related quality of life, depression, somatic anxiety, coping strategies and self-efficacy.Pain extent was directly related to neck, arm and headache pain intensity (all P < .01). Multiple linear regression revealed that pain extent was significantly associated only to the level of perceived disability (P < .01).Increased pain extent in people with CR is associated with higher headache, neck and arm pain intensity, and disability but not measures of general health, depression, somatic anxiety, coping strategies or self-efficacy.

Work-related musculoskeletal disorders among occupational fishermen: a systematic literature review

BACKGROUND

Commercial fishing constitutes an increased risk of musculoskeletal disorders (MSD), as it consists of heavy workloads and uncontrollable strenuous settings. The aims of this systematic review were to describe the prevalence of MSD among occupational fishermen and to identify risk factors for onset work-related MSD.

METHODS

All studies investigating MSD in occupational fishermen were systematically identified and reviewed. Searched databases were PubMed/MEDLINE, EMBASE and CINAHL. Two independent researchers performed the quality assessments of the studies.

RESULTS

From 292 articles identified, 16 articles consisting of 13 studies were suitable for inclusion. Prevalence of overall MSD ranged from 15% to 93%. The only consistent work-related risk factor was 'working part time', while other risk factors, such as vessel and job type showed conflicting results.

CONCLUSION

MSDs in occupational fishermen are common across countries. Variations observed in MSD prevalence might be due to differences in methodology, populations and definitions of MSD. Evidence on work-related risk factors for MSD is sparse and most studies were of poor methodological quality. Only working part time was identified as a consistent risk factor for MSD possibly caused by a healthy worker effect. There is a need for investigating causality in longitudinal studies, including both active and retired fishermen to better understand the complexity of MSD.

PROSPERO REGISTRATION NUMBER

CRD42020147318.

Association of objectively measured arm inclination with shoulder pain: A 6-month follow-up prospective study of construction and health care workers

OBJECTIVES

The aim was to determine the association of occupational arm inclination with shoulder pain in construction and health care workers.

METHODS

Arm inclination relative to the vertical was measured with an accelerometer placed on the dominant upper arm for up to four full days at baseline in 62 construction workers and 63 health care workers. The pain intensity in the shoulder and mechanical and psychosocial work factors were measured by self-reports at baseline and prospectively after 6 months. The associations between exposures and shoulder pain were analyzed with multilevel mixed-effects linear regressions.

RESULTS

For the total study population working with the dominant arm at inclinations > 30° and >120° was associated with lower levels of shoulder pain both cross-sectionally and after 6 months. Associations were attenuated when adjusting for individual and social factors, psychological state, and exposure during leisure time, especially for the high inclination levels. Analyses, only including subjects with no pain at baseline revealed no significant associations. While stratified analysis showed negative associations in the construction worker group, there were no significant association in health care workers. Compared to the number of hypotheses tested, the number of significant findings was low. Adjustment by Bonferroni-correction made almost all findings insignificant.

CONCLUSIONS

All analyses reflected a negative association between arm inclination and shoulder pain, but few analyses showed these associations to be statistically significant. If there is a relationship between arm inclination and shoulder pain, these findings could indicate that pain-avoidance may modify how workers perform their tasks.

Vibration and Ergonomic Exposures Associated With Musculoskeletal Disorders of the Shoulder and Neck

Background

According to the US Bureau of Labor Statistics, musculoskeletal disorders (MSDs) accounted for 32% of all nonfatal injury and illness cases in 2014 among full-time workers. Our objective was to review and summarize the evidence linking occupational exposures to vibration and awkward posture with MSDs of the shoulder and neck.

Methods

A literature search was conducted using the terms musculoskeletal disorders, vibration, and awkward posture. All types of observational epidemiologic studies, with the exception of case reports, published during 1998–2015 were included. Databases searched were MEDLINE (Ovid), Embase (Ovid), Scopus, Ergonomic Abstracts, NIOSHTIC-2, and Health and Safety Science Abstracts.

Results

Occupational exposures to whole-body or hand–arm vibration were significantly associated with or resulted in MSDs of the shoulder and neck. Awkward postures while working were also associated with MSDs in these locations. These findings were consistent across study designs, populations, and countries.

Conclusion

Occupational exposure to vibration and awkward posture are associated with shoulder and neck MSDs. Longitudinal studies are required to elucidate the mechanisms responsible for these associations, and intervention studies are warranted.

Long-term prognosis for neck-shoulder pain and disorders: a 14-year follow-up study

OBJECTIVES

The long-term prognosis for neck-shoulder pain and disorders and the impact of shoulder exposure among former sewing machine operators were investigated in a 14-year follow-up study.

METHODS

Information on neck-shoulder pain and disorders was collected by questionnaire and clinical examination at baseline in 243 female sewing machine operators and by questionnaire 14 years later. During follow-up, information on comorbidity and job exposures was obtained from registers and by linking register-based D-ISCO 88 codes with a job exposure matrix. Logistic regression analyses were performed to examine associations between neck-shoulder pain and disorders at baseline and neck-shoulder pain and physical functioning at follow-up.

RESULTS

We found an association between neck-shoulder disorders at baseline and neck-shoulder pain at follow-up (OR 5.9;95% CI 1.9 to 17.7), and between neck-shoulder pain at baseline and neck-shoulder pain at follow-up (OR 8.2;95% CI 3.5 to 19.2). Associations between neck-shoulder disorders and pain at baseline and limited physical functioning at follow-up had ORs of 5.0 (95% CI 1.5 to 16.1) and 2.2 (95% CI 1.1 to 4.6), respectively. In women still working in 2008, the association between neck-shoulder pain in 1994 and in 2008 seemed to be stronger for those in jobs with high job shoulder exposure.

CONCLUSIONS

The results suggest a long-term adverse prognosis for neck-shoulder pain. High job shoulder exposure can worsen this prognosis for those who continue working. This knowledge could influence the counselling given to similar workers and emphasises the need to prevent neck-shoulder pain.

Clinical prediction rules for prognosis and treatment prescription in neck pain: A systematic review

Clinical prediction rules (CPRs) developed to identify sub-groups of people with neck pain for different prognoses (i.e. prognostic) or response to treatments (i.e. prescriptive) have been recommended as a research priority to improve health outcomes for these conditions. A systematic review was undertaken to identify prognostic and prescriptive CPRs relevant to the conservative management of adults with neck pain and to appraise stage of development, quality and readiness for clinical application. Six databases were systematically searched from inception until 4th July 2016. Two independent reviewers assessed eligibility, risk of bias (PEDro and QUIPS), methodological quality and stage of development. 9840 records were retrieved and screened for eligibility. Thirty-two studies reporting on 26 CPRs were included in this review. Methodological quality of included studies varied considerably. Most prognostic CPR development studies employed appropriate designs. However, many prescriptive CPR studies (n = 12/13) used single group designs and/or analysed controlled trials using methods that were inadequate for identifying treatment effect moderators. Most prognostic (n = 11/15) and all prescriptive (n = 11) CPRs have not progressed beyond the derivation stage of development. Four prognostic CPRs relating to acute whiplash (n = 3) or non-traumatic neck pain (n = 1) have undergone preliminary validation. No CPRs have undergone impact analysis. Most prognostic and prescriptive CPRs for neck pain are at the initial stage of development and therefore routine clinical use is not yet supported. Further validation and impact analyses of all CPRs are required before confident conclusions can be made regarding clinical utility.

Is prolonged sitting at work associated with the time course of neck-shoulder pain? A prospective study in Danish blue-collar workers

OBJECTIVES

This study aimed to determine the extent to which objectively measured sitting time at work is associated with the course of neck-shoulder pain across 1 year in blue-collar workers.

METHODS

Data were analysed from 625 blue-collar workers in the Danish PHysical ACTivity cohort with Objective measurements (DPHACTO) cohort study (2012-2013). Objective data on sitting time were collected at baseline using accelerometry. Self-reported pain intensity (numeric rating scale 0-10) in the neck-shoulder region was registered for 1 year using repeated text messages (14 in total). Linear mixed models were used to determine the relationship between per cent time in sitting at work and trajectories of neck-shoulder pain, with and without adjustment for demographic, occupational and lifestyle factors, and baseline pain intensity.

RESULTS

More sitting time at work was associated with a faster decline in pain intensity over 12 months, as indicated by a statistically significant effect of sitting on pain trajectories in the crude (p=0.020) and fully adjusted models (p=0.027).

CONCLUSIONS

In blue-collar workers, more sitting time at work was associated with a favourable development of pain intensity over time. The relationship between sitting at work and pain needs further investigation before explicit recommendations and guidelines on sedentary behaviour among blue-collar workers can be developed.

Temporal patterns of sitting at work are associated with neck-shoulder pain in blue-collar workers: a cross-sectional analysis of accelerometer data in the DPHACTO study

Background

Our aim was to examine the extent to which temporal patterns of sitting during occupational work and during leisure-time, assessed using accelerometry, are associated with intense neck–shoulder pain (NSP) in blue-collar workers.

Methods

The population consisted of 659 Danish blue-collar workers. Accelerometers were attached to the thigh, hip, trunk and upper dominant arm to measure sitting time and physical activity across four consecutive days. Temporal sitting patterns were expressed separately for work and leisure by the proportion of total time spent sitting in brief bursts (0–5 min), moderate (>5–20 min) and prolonged (>20 min) periods. The peak NSP intensity during the previous 3 months was assessed using a numerical rating scale (range 0–10) and dichotomized into a lower (≤4) and higher (>4) NSP score. Logistic regression analyses with multiple adjustments for individual and occupational factors were performed to determine the association between brief, moderate and prolonged sitting periods, and NSP intensity.

Results

Time in brief bursts of occupational sitting was negatively associated with NSP intensity (adjusted OR 0.68, 95 % CI 0.48–0.98), while time in moderate periods of occupational sitting showed a positive association with NSP (adjusted OR 1.32, 95 % CI 1.04–1.69). Time in prolonged periods of occupational sitting was not associated with NSP (adjusted OR 0.78, 95 % CI 0.78–1.09). We found no significant association between brief, moderate or prolonged sitting periods during leisure, and NSP.

Conclusion

Our findings indicate that the association between occupational sitting time and intense NSP among blue-collar workers is sensitive to the temporal pattern of sitting.

Sleep as a predictive factor for the onset and resolution of multi-site pain: a 5-year prospective study

Background

Disturbed sleep and pain often co-exist and the relationship between the two conditions is complex and likely reciprocal. This 5-year prospective study examines whether disturbed sleep can predict the onset of multi-site pain, and whether non-disturbed sleep can predict the resolution of multi-site pain.

Methods

The cohort (n = 1599) was stratified by the number of self-reported pain sites: no pain, pain from 1–2 sites and multi-site pain (≥3 pain sites). Sleep was categorized by self-reported sleep disturbance: sleep A (best sleep), sleep B and sleep C (worst sleep). In the no-pain and pain-from-1–2 sites strata, the association between sleep (A, B and C) and multi-site pain 5 years later was analysed. Further, the prognostic value of sleep for the resolution of multi-site pain at follow-up was calculated for the stratum with multi-site pain at baseline. In the analyses, gender, age, body mass index, smoking, physical activity and work-related exposures were treated as potential confounders.

Results

For individuals with no pain at baseline, a significantly higher odds ratio for multi-site pain 5 years later was seen for the tertile reporting worst sleep [odds ratio (OR) 4.55; 95% confidence interval (CI) 1.28–16.12]. Non-disturbed (or less disturbed) sleep had a significant effect when predicting the resolution of multi-site pain (to no pain) (OR 3.96; 95% CI 1.69–9.31).

Conclusion

In conclusion, sleep could be relevant for predicting both the onset and the resolution of multi-site pain. It seems to be a significant factor to include in research on multi-site pain and when conducting or evaluating intervention programmes for pain.

Sleep disturbances predict future sickness absence among individuals with lower back or neck-shoulder pain: a 5-year prospective study

BACKGROUND

Musculoskeletal pain is one of the most common causes of sickness absence. Sleep disturbances are often co-occurring with pain, but the relationship between sleep and pain is complex. Little is known about the importance of self-reported sleep, when predicting sickness absence among persons with musculoskeletal pain. This study aims to study the association between self-reported sleep quality and sickness absence 5 years later, among individuals stratified by presence of lower back pain (LBP) and neck and shoulder pain (NSP).

METHODS

The cohort (n = 2286) in this 5-year prospective study (using data from the MUSIC-Norrtälje study) was stratified by self-reported pain into three groups: no LBP or NSP, solely LBP or NSP, and concurrent LBP and NSP. Odds ratios (ORs) for the effect of self-reported sleep disturbances at baseline on sickness absence (> 14 consecutive days), 5 years later, were calculated.

RESULTS

Within all three pain strata, individuals reporting the most sleep problems showed a significantly higher OR for all-cause sickness absence, 5 years later. The group with the most pronounced sleep problems within the concurrent LBP and NSP stratum had a significantly higher OR (OR 2.00; CI 1.09-3.67) also for long-term sickness absence (> 90 days) 5 years later, compared to the group with the best sleep. CONCLUSIONS Sleep disturbances predict sickness absence among individuals regardless of co-existing features of LBP and/or NSP. The clinical evaluation of patients should take possible sleep disturbances into account in the planning of treatments.

[Translation, cultural adaptation, validity and reliability of the shoulder rating questionnaire for use in Brazil]

OBJECTIVE

To translate and culturally adapt the Shoulder Rating Questionnaire (SRQ) to the Brazilian Portuguese language, and to determine its validity, reliability and sensitivity to change in patients with functional impairment of the shoulder.

METHODS

After translation and back-translation of the original version by four independent translators, the instrument was reviewed by a committee of experts and subsequently applied to eight patients with shoulder injury (target audience) to produce the Portuguese version. Then, this version was applied to 102 patients selected from four reference centers for functional treatment of the shoulder, who had a variety of clinical diagnoses, educational levels, socioeconomic, and cultural backgrounds. The evaluation was performed twice with an interval of four weeks between each application.

RESULTS

The Brazilian version of SRQ was equivalent in terms of semantics and showed good levels of reliability (Cronbach's Alpha=0.89 and ICC=0.83). The reproducibility was high (Spearman Correlation Coefficient=0.82) and validity of the items that ranged from 0.54 to 0.99 was considered excellent. The Cohen's d and T test for repeated measures showed that the instrument is able to monitor and track improvements in shoulder function.

CONCLUSION

Psychometric criteria were found, which justify the applicability of the Brazilian version of SRQ in individuals with shoulder functional impairments.

Persistent of Neck/Shoulder Pain among Computer Office Workers with Specific Attention to Pain Expectation, Somatization Tendency, and Beliefs

BACKGROUND

Neck and shoulder pains are the prevalent complaints among computer office workers. The purpose of this study was to assess the relationship of somatization tendency, expectation of pain, mental health and beliefs about causation of pain with persistence of neck/shoulder pains among computer office workers.

METHODS

This research is a kind of prospective cohort study with 1-year follow-up. It has done among all eligible computer office workers of Shahroud universities (n = 182) in 2008-2009 and 1-year later. Data were collected using the Cultural and Psychosocial Influences on Disability questionnaire. Multiple logistic regression analysis was used to analyze the data through SPSS (P < 0.05).

RESULTS

At the baseline 100 (54.9%) of participants reported neck/shoulder pains and at follow-up 34.3% of them reported persistence pains. Significant relationships were found between persistence of neck/shoulder pains and negative expectation about pain in next 1-year P = 0.002, (odds ratio [OR] =8.3, 95% confidence interval [CI]: 2.1-32.9) and somatization tendency P = 0.01, (OR = 6.5, 95% CI: 1.6-27.4).

CONCLUSIONS

Pain expectation and somatization tendency recognized as associated risk factors of persistent neck/shoulder pain among computer operators. This confirmed some other similar studies on work-related musculoskeletal disorders in Europe countries in recent years.

Are job strain and sleep disturbances prognostic factors for neck/shoulder/arm pain? A cohort study of a general population of working age in Sweden

OBJECTIVE

To study whether job strain, that is, psychological job demands and decision latitude, and sleep disturbances among persons with occasional neck/shoulder/arm pain (NSAP) are prognostic factors for having experienced at least one episode of troublesome NSAP, and to determine whether sleep disturbances modify the association between job strain and troublesome NSAP.

DESIGN

Prospective cohort study.

SETTING

Stockholm, Sweden.

PARTICIPANTS

A population-based cohort of individuals with occasional NSAP (n=6979) who answered surveys in 2006 and 2010.

OUTCOME MEASURES

Report of at least one episode of troublesome NSAP in 2010.

RESULTS

The ORs for troublesome NSAP at follow-up were in individuals exposed to passive jobs 1.2 (95% CI 0.9 to 1.4); to active jobs 1.3 (95% CI 1.1 to 1.5); to high strain 1.5 (95% CI 1.0 to 2.4); to mild sleep disturbances 1.4 (95% CI 1.3 to 1.6) and to severe sleep disturbances 2.2 (95% CI 1.6 to 3.0). High strain and active jobs were associated with having experienced at least one episode of troublesome NSAP during the previous 6 months in persons with sleep disturbances, but not in individuals without sleep disturbances.

CONCLUSIONS

Our results indicate that high strain, active jobs and sleep disturbances are prognostic factors that should be taken into account when implementing preventive measures to minimise the risk of troublesome NSAP among people of working age. We suggest that sleep disturbances may modify the association between high strain and troublesome NSAP.

Natural course of rotator cuff syndrome in a French working population

BACKGROUND

The aim was to assess the persistence of rotator cuff syndrome (RCS) in workers and to study associations with personal and work-related factors, job change, exposure change and treatment.

METHODS

At baseline, 274 workers suffered from RCS, of whom 150 were followed up. Three groups were constituted: (1) a RCS recovery group, (2) a shoulder pain without RCS group, and (3) a RCS without recovery group. We studied the differences between groups (1) and (3) because of the low number of workers in group (2).

RESULTS

Recovery occurred in 61.5% of men and 51.4% of women. Factors related to work were associated with persistence of RCS in men whereas upper limb pain and absence of job rotation were associated with persistence of RCS in women.

CONCLUSION

This descriptive study showed that a high percentage of workers recovered and several personal and work-related factors were associated with persistent RCS. Larger prospective studies are needed to confirm these results.

Musculoskeletal disorders and occupational exposures: How should we judge the evidence concerning the causal association?

Musculoskeletal disorders (MSDs) affecting the back, upper and lower extremities are widespread in the general population, implying a variety of causal factors. Multiple causes are not mutually exclusive, and a high background rate does not preclude associations with specific factors that are uncommon in the general population. MSDs have well-documented associations with occupational ergonomic stressors such as repetitive motion, heavy lifting, non-neutral postures, and vibration. Organizational features of the work environment, such as time pressure and low decision latitude, may also play a role, at least by potentiating the effects of physical loading. Numerous systematic reviews have mostly concurred with these overall findings. Nevertheless, some continue to debate whether MSDs are sometimes work-related, even for those performing jobs with repetitive and routinized tasks, heavy lifting, and/or pronounced postural strain. This article discusses (1) some epidemiologic features of MSDs that underlie that debate; and (2) the question of what should appropriately be considered a gold standard for scientific evidence on an etiological question such as the health effects of a non-voluntary exposure, such as an occupational or environmental agent. In particular, randomized clinical trials have little relevance for determining the health effects of non-therapeutic risk factors.

Transient decrease in nociceptor GRK2 expression produces long-term enhancement in inflammatory pain

In heterozygous mice, attenuation of G-protein-coupled receptor kinase 2 (GRK2) level in nociceptors is associated with enhanced and prolonged inflammatory hyperalgesia. To further elucidate the role of GRK2 in nociceptor function we reversibly decreased GRK2 expression using intrathecal antisense oligodeoxynucleotide (AS-ODN). GRK2 AS-ODN administration led to an enhanced and prolonged hyperalgesia induced by prostaglandin E(2), epinephrine and carrageenan. Moreover, this effect persisted unattenuated 2weeks after the last dose of antisense, well after GRK2 protein recovered, suggesting that transient attenuation of GRK2 produced neuroplastic changes in nociceptor function. Unlike hyperalgesic priming induced by transient activation of protein kinase C epsilon (PKCε), (Aley et al., 2000; Parada et al., 2003b), the enhanced and prolonged hyperalgesia following attenuation of GRK2 is PKCε- and cytoplasmic polyadenylation element binding protein (CPEB)-independent and is protein kinase A (PKA)- and Src tyrosine kinase (Src)-dependent. Finally, rats treated with GRK2 AS-ODN exhibited enhanced and prolonged hyperalgesia induced by direct activation of second messengers, adenyl cyclase, Epac or PKA, suggesting changes downstream of G-protein-coupled receptors. Because inflammation can produce a decrease in GRK2, such a mechanism could help explain a predilection to develop chronic pain, after resolution of acute inflammation.

Effects of tailored neck-shoulder pain treatment based on a decision model guided by clinical assessments and standardized functional tests. A study protocol of a randomized controlled trial

Background

A major problem with rehabilitation interventions for neck pain is that the condition may have multiple causes, thus a single treatment approach is seldom efficient. The present study protocol outlines a single blinded randomised controlled trial evaluating the effect of tailored treatment for neck-shoulder pain. The treatment is based on a decision model guided by standardized clinical assessment and functional tests with cut-off values. Our main hypothesis is that the tailored treatment has better short, intermediate and long-term effects than either non-tailored treatment or treatment-as-usual (TAU) on pain and function. We sub-sequentially hypothesize that tailored and non-tailored treatment both have better effect than TAU.

Methods/Design

120 working women with minimum six weeks of nonspecific neck-shoulder pain aged 20–65, are allocated by minimisation with the factors age, duration of pain, pain intensity and disability in to the groups tailored treatment (T), non-tailored treatment (NT) or treatment-as-usual (TAU). Treatment is given to the groups T and NT for 11 weeks (27 sessions evenly distributed). An extensive presentation of the tests and treatment decision model is provided. The main treatment components are manual therapy, cranio-cervical flexion exercise and strength training, EMG-biofeedback training, treatment for cervicogenic headache, neck motor control training. A decision algorithm based on the baseline assessment determines the treatment components given to each participant of T- and NT-groups. Primary outcome measures are physical functioning (Neck Disability Index) and average pain intensity last week (Numeric Rating Scale). Secondary outcomes are general improvement (Patient Global Impression of Change scale), symptoms (Profile Fitness Mapping neck questionnaire), capacity to work in the last 6 weeks (quality and quantity) and pressure pain threshold of m. trapezius. Primary and secondary outcomes will be reported for each group with effect size and its precision.

Discussion

We have chosen not to include women with psychological ill-health and focus on biomedical aspects of neck pain. Future studies should aim at including psychosocial aspects in a widened treatment decision model. No important adverse events or side-effects are expected.

Trial registration

Current Controlled Trials registration ISRCTN49348025.

Psychosocial work stressors as antecedents of musculoskeletal problems: a systematic review and meta-analysis of stability-adjusted longitudinal studies

Although the relationship between psychosocial workplace conditions and musculoskeletal problems has been extensively studied, the causal impact of psychosocial workplace factors in the development of musculoskeletal problems remains unclear. The purpose of the present study was to conduct a systematic review of baseline-adjusted prospective longitudinal studies estimating the lagged effect of psychosocial risk factors on musculoskeletal problems in industrialized work settings. A literature review was conducted by searching the MEDLINE, EMBASE, and PsychINFO databases dated until August 2009. The authors classified studies into categories of psychological work stressors and musculoskeletal problems. Available effect sizes were converted to odds ratios (OR). ORs were then pooled for each stressor-problem relationship using a random-effects model. Additionally, the possibility of publication bias was assessed with the Duval and Tweedie nonparametric "trim and fill" procedure. In total, 50 primary studies fulfilled inclusion criteria. Within these studies at least five effect sizes were available for 23 of the 45 possible psychosocial work stress-musculoskeletal problems relationships, leaving 9 psychosocial variables and four musculoskeletal problem areas for analyses. Of these 23 relationships, pooled OR estimates were positive and significant ranging from 1.15 to 1.66 with the largest pooled OR estimating the relationship between highly monotonous work and lower back pain. The lagged effect of low social support on lower limb problems was the only effect size for which the statistical test for bias was significant. Most psychosocial stressors had small but significant lagged effects on the development of musculoskeletal problems. Thus, organizational interventions to minimize these stressors may be promising in reducing one risk factor for the development of employee musculoskeletal problems.

Prevalence of musculoskeletal disorders among cashew factory workers

Work-related musculoskeletal disorders (WRMSDs) are impairments of the bodily structures, such as muscles, joints, tendons, ligaments, nerves, or the localized blood circulation system, which are caused or aggravated primarily by the performance of work and by the effects of the immediate environment in which work is carried out. Types of work in the cashew factory include cutting, peeling, grading, packing, and boiling. All these activities have risk factors for the musculoskeletal disorders, which include repetition, contact stress, forceful contraction, awkward postures, as well as sustained positions. The objective of this cross-sectional study was to find out the prevalence of musculoskeletal disorders among cashew factory workers. A cross-sectional descriptive study was conducted on 246 cashew factory workers, working in a randomly selected factory of a selected locality in Karkala taluk of Udupi district, Karnataka. Participants' name, age, gender, literacy level, income, type of work, duration of employment, hours of work per day, hand dominance, pain and discomfort status were obtained by structured interview. A total of 246 cashew factory workers participated in the study. Data were analyzed using SPSS version 14. Descriptive statistics was used to summarize the data. Around 28.5% (n = 70) reported pain, whereas 71.5% (n = 176) of workers did not report pain. The largest number of workers (n = 22; 32.4%) complained of pain in the knee, followed by back (n = 21; 30.9%) and then shoulder (n = 8; 11.8%). Seventy percent of the workers who reported pain were having more than 5 years of work experience. A 68.6% (n = 48) of the workers who reported pain were in the cutting category, followed by the grading (17%; n = 12), boiling (8.6%; n = 6), and peeling (5.7%; n = 4) categories. Prevalence of pain and discomfort among workers was 28.5%, which is a not ignorable and has to be addressed. Self-reported pain and discomfort were more prevalent in knee, followed by back and then shoulder.

Longitudinal evidence for the association between work-related physical exposures and neck and/or shoulder complaints: a systematic review

BACKGROUND

Most existing reviews focus on evidence for the association between neck and/or shoulder complaints and physical exposures at the workplace gathered from cross-sectional studies. In comparison, this review summarizes existing evidence from longitudinal studies only.

METHODS

A systematic literature research was conducted in Medline and EMBASE (1975-2009), and all studies were scanned by at least two researchers according to strict inclusion criteria. Levels of evidence were assigned according to the number of studies reporting similar findings, and according to the methodological quality of the included studies.

RESULTS

Altogether 21 longitudinal studies (19 high-quality studies) met the inclusion criteria and were included in this review. In comparison with former reviews, we found strong evidence for an association between shoulder complaints and manual material handling (MMH) (range between Odds Ratio (OR) 1.4 and 4.9), vibration (range between OR 1.6 and OR 2.5), trunk flexion or rotation (range between OR 1.8 and OR 5.1), and working with hands above shoulder level (range between OR 1.1 and OR 1.8). Apart from that, the included studies confirmed existing knowledge on the association between physical exposures at the workplace and neck and/or shoulder complaints.

CONCLUSIONS

This analysis of longitudinal studies allowed for new evidence with regard to four cause-effect chains between physical exposures at work and the development of shoulder, neck and neck/shoulder complaints. As outcome variables varied greatly among the included studies, harmonization in studies on musculoskeletal research is desirable.

High heritability for concurrent low back and neck-shoulder pain: a study of twins

STUDY DESIGN

A cross-sectional study on 21,225 twins based on a Web-based questionnaire was performed in 2005-2006 and administered by the Swedish Twin Registry.

OBJECTIVE

To investigate the importance of genetic factors for the occurrence of "Concurrent low back (LBP) and neck-shoulder pain (NSP)" as well as of "Solely LBP," and "Solely NSP" in an adult population of women and men.

SUMMARY OF BACKGROUND DATA

Many individuals suffering from LBP also have concurrent NSP, and little is known about the factors influencing the occurrence of this spinal comorbidity.

METHODS

Heritability of Concurrent LBP and NSP, solely LBP, and solely NSP was analyzed in 2934 monozygotic twin pairs, 2009 same-sex dizygotic (DZ) twin pairs, and 1960 opposite-sex DZ twin pairs without any known rheumatic disorders using structural equation modeling (SEM).

RESULTS

The SEM showed that 60% of the total variance for concurrent LBP and NSP can be explained by additive genetic effects, which was twice as large as for solely LBP (30%) and more than twice as large as for solely NSP (24%).

CONCLUSION

Genetic factors had a considerably greater importance for the occurrence of concurrent LBP and NSP compared with solely LBP or solely NSP. The influence of genetic factors was similar for solely LBP and solely NSP.

Predictors of shoulder pain and disability index (SPADI) and work status after 1 year in patients with subacromial shoulder pain

Background

Shoulder pain is a common complaint in primary health care and has an unfavourable outcome in many patients. The objectives were to identify predictors for pain and disability (SPADI) and work status in patients with subacromial shoulder pain.

Methods

Secondary analyses of data from a randomized clinical controlled trial were performed. Outcome measures were the absolute values of the combined Shoulder Pain and Disability Index (SPADI) and work status 1 year after treatment with supervised exercises (SE) or radial extracorporeal shockwave therapy (rESWT). Predictors of outcome were investigated using multiple linear regression (SPADI) and logistic regression (work status).

Results

104 patients were included. Low education (≤ 12 years), previous shoulder pain, and a high baseline SPADI score predicted poor results with these variables explaining 29.9% of the variance in SPADI score at 1 year. Low education and poor self-reported health status predicted a work status of "not working": Odds Ratio, OR = 4.3(95% CI (1.3 to 14.9)), p = 0.02 for education, and OR = 1.06 (95% CI (1.0 to 1.1)), p = 0.001 for self-reported health status, respectively. Adjustments for age, gender, and treatment group were performed, but did not change the results.

Conclusion

Education was the most consistent predictor of pain and disability, and work status at 1 year follow-up. Also, baseline SPADI score, previous shoulder pain and self-reported health status predicted outcome.

Trial registration

Clinical trials NCT00653081

Follow-up of neck and shoulder pain among sewing machine operators: The Los Angeles garment study

BACKGROUND

The aim of the present study is to explore factors affecting or modifying self-reported neck/shoulder pain in sewing machine operators.

METHODS

We investigated self-report neck/shoulder pain in 247 workers who participated in a 4-month prospective intervention study for musculoskeletal disorders. All participants were immigrants. We examine the influence of individual and work-related factors on changes in neck/shoulder pain during follow-up employing linear mixed models with time-spline functions.

RESULTS

We observed a dramatic decline (72%) in self-reported pain intensity in the first month of follow-up, followed by a small increase from the first to fourth month (4% per month). Workers who perceived and reported their physical workload as high or worked overtime experienced less overall pain reduction. Higher baseline pain intensity, being of Hispanic ethnicity (vs. Asian), and taking cumulative daily rest time during work of 35 min or more allowing for muscles to rest were associated with a larger pain reduction in the first month, but not thereafter.

CONCLUSION

Our findings indicate that some work-related factors may be of clinical relevance for reducing neck/shoulder pain. Having lower physical workloads and less overtime work should be considered when treating patients or planning workplace interventions for managing work-related musculoskeletal disorders in this underserved immigrant population.

Working height, block mass and one- vs. two-handed block handling: the contribution to low back and shoulder loading during masonry work

The goal of this study was to compare the effects of the task variables block mass, working height and one- vs. two-handed block handling on low back and shoulder loading during masonry work. In a mock-up of a masonry work site, nine masonry workers performed one- and two-handed block-lifting and block-placing tasks at varying heights (ranging from floor to shoulder level) with blocks of varying mass (ranging from 6 to 16 kg). Kinematics and ground reaction forces were measured and used in a 3-D linked segment model to calculate low back and shoulder loading. Increasing lifting height appeared to be the most effective way to reduce low back loading. However, working at shoulder level resulted in relatively high shoulder loading. Therefore, it was recommended to organise masonry work in such a way that blocks are handled with the hands at about iliac crest height as much as possible.