Hard work never hurt anyone: or did it? A review of occupational associations with soft tissue musculoskeletal disorders of the neck and upper limb

A single cell atlas of frozen shoulder capsule identifies features associated with inflammatory fibrosis resolution

Frozen shoulder is a spontaneously self-resolving chronic inflammatory fibrotic human disease, which distinguishes the condition from most fibrotic diseases that are progressive and irreversible. Using single-cell analysis, we identify pro-inflammatory MERTKlowCD48+ macrophages and MERTK + LYVE1 + MRC1+ macrophages enriched for negative regulators of inflammation which co-exist in frozen shoulder capsule tissues. Micro-cultures of patient-derived cells identify integrin-mediated cell-matrix interactions between MERTK+ macrophages and pro-resolving DKK3+ and POSTN+ fibroblasts, suggesting that matrix remodelling plays a role in frozen shoulder resolution. Cross-tissue analysis reveals a shared gene expression cassette between shoulder capsule MERTK+ macrophages and a respective population enriched in synovial tissues of rheumatoid arthritis patients in disease remission, supporting the concept that MERTK+ macrophages mediate resolution of inflammation and fibrosis. Single-cell transcriptomic profiling and spatial analysis of human foetal shoulder tissues identify MERTK + LYVE1 + MRC1+ macrophages and DKK3+ and POSTN+ fibroblast populations analogous to those in frozen shoulder, suggesting that the template to resolve fibrosis is established during shoulder development. Crosstalk between MerTK+ macrophages and pro-resolving DKK3+ and POSTN+ fibroblasts could facilitate resolution of frozen shoulder, providing a basis for potential therapeutic resolution of persistent fibrotic diseases.

Research advances and trends in the surgical treatment of carpal tunnel syndrome from 2003 to 2022: A CiteSpace-based bibliometric analysis

Background

Carpal Tunnel Syndrome (CTS) is one of the most common peripheral neuropathies. The typical symptoms are tingling and numbness in the median nerve distribution of the hand. Current treatment for CTS includes general conservative treatment and surgical treatment. Surgical treatment plays a crucial role in the management of CTS, but little bibliometric analysis has been conducted on it. Therefore, this study aimed to map the literature co-citation network using CiteSpace (6.1 R4) software. Research frontiers and trends were identified by retrieving subject headings with significant changing word frequency trends, which can be used to predict future research advances in the surgical treatment of CTS.

Methods

Publications on the surgical treatment of CTS in the Web of Science database were collected between 2003 and 2022. CiteSpace software was applied to visualize and analyze publications, countries, institutions, journals, authors, references, and keywords.

Results

A total of 336 articles were collected, with the USA being the major publishing power in all countries/regions. JOURNAL OF HAND SURGERY AMERICAN VOLUME was the journal with the most published and co-cited articles. Based on keyword and reference co-citation analysis, keywords such as CTS, surgery, release, median nerve, and diagnosis were the focus of the study.

Conclusion

The results of this bibliometric study provide clinical research advances and trends in the surgical treatment of patients with CTS over the past 20 years, which may help researchers to identify hot topics and explore new directions for future research in the field.

Neurogenic Thoracic Outlet Syndrome

BACKGROUND

Thoracic outlet syndrome (TOS) refers to a group of disorders in which there is compression of and/or damage to the neurovascular structures at the thoracic outlet, i.e., at the transition from chest to neck. The incidence of neurogenic thoracic outlet syndrome (nTOS) is estimated to be 2-3 / 100 000 / year, with an estimated prevalence of 10 / 100 000. Patients present with upper extremity sensorimotor symptoms that are often related to movement. The aim of the present article is to highlight the clinical presentation patterns of nTOS and to provide an overview of its diagnosis and treatment.

METHODS

Selective literature search for prospective observational studies and RCTs, including systematic reviews and metaanalyses.

RESULTS

There is no multicenter randomized controlled trial available on the treatment of nTOS. Prospective observational studies with a hierarchical study design report a positive effect of physiotherapy in 27-59% of cases. After unsuccessful conservative treatment, up to 56-90% benefit from surgical management. Patients with nTOS are more severely affected compared with those with other forms of TOS and benefit less from transaxillary first rib resection. nTOS patients who underwent supraclavicular decompression without rib resection had excellent surgical outcomes in 27%, good outcomes in 36%, acceptable outcomes in 26%, and poor surgical outcomes in 11% of cases. There is no systematic comparison available of the types of surgical management involved. Also, there is currently no uniform classification available for all medical sub-disciplines. Therefore, interpretation, and comparability of the study results are limited.

CONCLUSION

Although nTOS is the most common form of TOS, studies on its treatment are currently limited in terms of numbers and quality. The type of surgical management varies according to the experience and preference of the surgeon, treating specialty, special anatomic features, and clinical symptoms.

Sex differences in upper limb musculoskeletal biomechanics during a lifting task

Women experience higher prevalence of work-related upper limb musculoskeletal disorders compared to men. Previous studies have investigated the biological, kinematic and electromyographic sex-related differences during a lifting task but the actual differences in musculoskeletal loads remain unknown. We investigated the sex differences in three musculoskeletal indicators: the sum of muscle activations, the sum of muscle forces and the relative time spent beyond a shear-compression dislocation ratio. A musculoskeletal model was scaled on 20 women and 20 men lifting a 6 or 12kg box from hip to eye level. Women generated more muscle forces and activations than men, regardless of the lifted mass. Those differences occurred when the box was above shoulder level. In addition, women might spend more time beyond a shear-compression dislocation ratio. Our work suggests higher musculoskeletal loads among women compared to men during a lifting task, which could be the result of poor technique and strength difference.

Work above shoulder level and shoulder complaints: a systematic review

OBJECTIVE

To investigate the association and the exposure-response relationship between work above shoulder height and shoulder pain or disorders.

METHODS

A systematic search was performed in Medline, Embase, and Health and Safety Science Abstracts. Included were articles with prospective cohort, case-control, cross-sectional, or intervention study designs. Quality assessment was based on an evaluation scheme adjusted to study design and normalized to 100%. The cut-off for sufficient quality to include articles was above 40% and cut-off for high-quality articles was above 50% of maximal score. The level of strength of evidence for an association between exposure and effect was assessed according to the GRADE guidelines.

RESULTS

Thirty-four articles were included. Articles that document large effects (higher risk estimates; OR ≥ 2) have higher quality score, include analyses of severe arm elevation, more often use clinical outcome, and report an exposure-response relationship compared to studies reporting lower risk estimates. The studies that reported large effects were all significant. An exposure-response relationship was found in many high-quality studies when relating exposure intensity of arm elevation (level of arm elevation, amplitude) as well as duration of arm elevation, especially > 90°.

CONCLUSION

We conclude on a limited evidence for an association between arm elevation at work and shoulder disorders. Severe arm elevation with elbows above shoulder level (i.e., > 90°) shows a moderate evidence for an association with shoulder disorders.

Understanding the patient profile and health-related quality of life in patients presenting for hand surgery

The aim of this descriptive epidemiological study of patients, referred to and selected for surgery at a UK tertiary hand centre, was to investigate patterns of common hand disorders and their impact on those individuals. A prospective collection of patient-reported outcome scores was carried out in patients before operation using the Patient Outcomes of Surgery Hand/Arm and the Euro-Qol 5 dimension three-level measures. Patient participation was voluntary and data collected over a 4-year period are discussed. Patient-reported outcome scores were calculated using appropriate algorithms. The results show correlation between the number of comorbidities and both symptoms and activity domains of the Patient Outcomes of Surgery Hand/Arm; higher symptom scores were seen in women. There was no increase in scores for older patients or those from more deprived areas. Population-based research using recognized patient-reported outcome measurement tools could aid future health service planning. Level of evidence: IV.

Prevalence of musculoskeletal disorders among Indian railway sahayaks

Railway sahayak or also known as coolie is one of the oldest occupations in India. This occupational group is continuously subjected to various musculoskeletal problems due to repetitive load exertion in unnatural postures. The present research aims to examine the prevalence of musculoskeletal disorders (MSDs) among Indian railway sahayaks. A cross-sectional study has been conducted on a sample of 51 male sahayaks. With a modified Nordic questionnaire, data were collected on their demographics, work, and musculoskeletal pain history. Electromyography (EMG) of the upper trapezius muscle of selected 12 healthy sahayaks having no history of neck-shoulder complaints were analyzed under different load lifting and carrying conditions. Additionally, ergonomic risk levels were recorded using Rapid Entire Body Assessment method. The questionnaire revealed that for the past 1 year prevalence, the most affected body regions of railway sahayaks were neck (47%), shoulder (51%), lower back (43%), and knee (47%). The association between age group and MSDs in different body regions were found significant (p = 0.012 for neck, p = 0.017 for shoulder, etc.). Work experience also had a significant relation to the MSDs in different body regions (p = 0.013 for shoulder,p = 0.023 for calf, etc.). Analysis of variance reveals high significance level between EMG values and tasks performed by the sahayaks. In conclusion, railway sahayaks were found to have high rate of MSDs which may be associated with lifting/carrying heavy loads in awkward postures. Ergonomic interventions must be implemented to reduce the risk level on this group of workers.

The relationship between the development of musculoskeletal disorders, body mass index, and academic stress in Bahraini University students

Background

There are many mechanisms in which stress can lead to weight gain thus high a BMI. The endocrine and inflammatory pathway can directly increase abdominal adiposity. Another way in which stress leads to weight gain is through changes in health behaviors. The study aimed to investigate the prevalence of musculoskeletal disorders (MSDs) among healthy students of Ahlia University, and to determine the relationship between the development of MSDs and academic stressors and body mass index.

Methods

Self-administered questionnaires were distributed to 94 students aged 18-26 years who were enrolled at various Ahlia University colleges and met other inclusion criteria. The students responded to the standardized Nordic musculoskeletal questionnaire and the modified College Student Stress Inventory regarding musculoskeletal symptoms and academic stressors. Height and weight measurements were also obtained to determine body mass index.

Results

A total of 77.66% reported MSDs in one or more body part, with the prevalence being higher among women than among men. The 7-day prevalence of MSDs severe enough to interfere with activities of daily living was 60.64%, and 44.68% by female and male students, respectively. There was a significant relationship between academic stress and MSDs in the neck, shoulders, lower back, and hips, while the relationship between MSDs, and body mass index, academic stress, and grade point average was not significant.

Conclusions

The prevalence of MSDs among Ahlia University students was found to be high. Apart from the positive correlation between academic stress and MSDs in certain body parts, other correlations were not significant.

Shoulder Pain Assessment for the Occupational Health Nurse

Shoulder pain is a common complaint in the workplace. A shoulder condition may arise from acute trauma or non-traumatic work-related activities. Shoulder pain falls into three categories: acute, chronic, and referred pain. The occupational health nurse can document detailed health histories and focused complaint-driven physical examinations. Nurses' expert assessments can guide injured workers to necessary treatment, case management, and return to full employment.

Prediction of Muscle Fatigue during Minimally Invasive Surgery Using Recurrence Quantification Analysis

Due to its inherent complexity such as limited work volume and degree of freedom, minimally invasive surgery (MIS) is ergonomically challenging to surgeons compared to traditional open surgery. Specifically, MIS can expose performing surgeons to excessive ergonomic risks including muscle fatigue that may lead to critical errors in surgical procedures. Therefore, detecting the vulnerable muscles and time-to-fatigue during MIS is of great importance in order to prevent these errors. The main goal of this study is to propose and test a novel measure that can be efficiently used to detect muscle fatigue. In this study, surface electromyography was used to record muscle activations of five subjects while they performed fifteen various laparoscopic operations. The muscle activation data was then reconstructed using recurrence quantification analysis (RQA) to detect possible signs of muscle fatigue on eight muscle groups (bicep, triceps, deltoid, and trapezius). The results showed that RQA detects the fatigue sign on bilateral trapezius at 47.5 minutes (average) and bilateral deltoid at 57.5 minutes after the start of operations. No sign of fatigue was detected for bicep and triceps muscles of any subject. According to the results, the proposed novel measure can be efficiently used to detect muscle fatigue and eventually improve the quality of MIS procedures with reducing errors that may result from overlooked muscle fatigue.

Occupation as a potential contributing factor for temporomandibular disorders, bruxism, and cervical muscle pain: a controlled comparative study

The aim of the study was to compare the prevalence of cervical muscle pain (CMP) and myogenic temporomandibular disorders (MFP) among female dentists, high-tech workers, and a group of subjects employed in other occupations; to investigate the associations among CMP, MFP, and bruxism in those groups; and to evaluate the influence of work-related stress on MFP and CMP. Evaluation was based on clinical examinations of MFP and CMP and self-reported questionnaires concerning pain and stress. The diagnosis of sleep bruxism was adapted using the validated diagnostic criteria of the American Academy of Sleep Medicine (International Classification of Sleep Disorders (ICSD-2), 2005, Westchester, IL), whilst the diagnosis of awake bruxism was made on the basis of a questionnaire. The odds of a subject with MFP experiencing concurrent CMP or bruxism (sleep and/or awake) ranged from 2.603 to 3.077. These results suggest that high-tech workers and dentists are at greater risk for developing temporomandibular disorders (TMDs) and CMP when compared with general occupation workers, as defined in this study. Furthermore, the associations shown here between TMDs and CMP highlight the importance of palpating neck musculature as part of any routine examination of TMD.

Shoulder disorders and occupation

Shoulder pain is very common, and it causes substantial morbidity. Standardised classification systems based upon presumed patho-anatomical origins have proved poorly reproducible and hampered epidemiological research. Despite this, there is evidence that exposure to combinations of physical workplace strains such as overhead working, heavy lifting and forceful work as well as working in an awkward posture increases the risk of shoulder disorders. Psychosocial risk factors are also associated. There is currently little evidence to suggest that either primary prevention or treatment strategies in the workplace are very effective, and more research is required, particularly around the cost-effectiveness of different strategies.

The role of ergonomic training interventions on decreasing neck and shoulders pain among workers of an Iranian automobile factory: a randomized trial study

BACKGROUND

Ergonomic training had been implemented for prevention or reduction of neck and shoulder complaints among workers. The purpose of the present study was to assess the role of ergonomic training intervention on decreasing the prevalence of neck and shoulder complaints among workers of an automobile factory.

METHODS

Within the present randomized clinical trial, the role of three ergonomic training methods on the prevalence of neck and shoulders pain among 503 workers of an automobile factory (Response rate: 94.23%) was assessed. The eligible workers were randomly allocated into the following three interventional (pamphlet, lecture, workshop) groups and one control group. The Nordic questionnaire was used to assess the prevalence of neck and shoulder complaints. We followed and assessed the prevalence of neck and shoulders complaints among the study employees before and one year after the intervention. We used chi-square and Mann-Whitney tests to compare the prevalence of neck and shoulder complaints between the trial and control groups. A two-tailed P-value less than or equal to 0.05 was considered statistically significant.

RESULTS

The prevalence of neck and shoulders complaints among the study employees at the recent week (p= 0.002) and year (p= 0.02) had been significantly decreased in the study employees after participating in the study workshop. The prevalence of neck and shoulders complaints at the recent week and year did not significantly changed in the study employees after receiving the pamphlet and lecture as ergonomic trainings.

CONCLUSION

Workshop as an ergonomic training method had an effective and powerful role on decreasing the prevalence of neck and shoulders complaints among workers.

Relationship between mental workload and musculoskeletal disorders among Alzahra Hospital nurses

BACKGROUND

Musculoskeletal disorders (MSDs) are a serious problem among the nursing staff. Mental workload is the major cause of MSDs among nursing staff. The aim of this study was to investigate the mental workload dimensions and their association with MSDs among nurses of Alzahra Hospital, affiliated to Isfahan University of Medical Sciences.

MATERIALS AND METHODS

This descriptive cross-sectional study was conducted on 247 randomly selected nurses who worked in the Alzahra Hospital in Isfahan, Iran in the summer of 2013. The Persian version of National Aeronautics and Space Administration Task Load Index (NASA-TLX) (measuring mental load) specialized questionnaire and Cornell Musculoskeletal Discomfort Questionnaire (CMDQ) was used for data collection. Data were collected and analyzed by Pearson correlation coefficient and Spearman correlation coefficient tests in SPSS 20.

RESULTS

Pearson and Spearman correlation tests showed a significant association between the nurses' MSDs and the dimensions of workload frustration, total workload, temporal demand, effort, and physical demand (r = 0.304, 0.277, 0.277, 0.216, and 0.211, respectively). However, there was no significant association between the nurses' MSDs and the dimensions of workload performance and mental demand (P > 0.05).

CONCLUSIONS

The nurses' frustration had a direct correlation with MSDs. This shows that stress is an inseparable component in hospital workplace. Thus, reduction of stress in nursing workplace should be one of the main priorities of hospital managers.

Classifying infectious disease outbreaks to improve timeliness and efficiency of response

Following the intentional dissemination of B.anthracis through the U.S. Postal Service in 2001, use of the term "naturally occurring" to classify some infectious disease outbreaks has become more evident. However, this term is neither a scientific nor an epidemiologic classification that is helpful in describing either the source or the mode of transmission in outbreaks. In this paper, the authors provide examples of how and when the public health community has recognized potentially flawed or misleading taxonomy in the past and taken steps to improve the taxonomy's accuracy and usefulness. We also offer examples of alternative terms for classifying outbreaks since inaccurate descriptions of outbreaks could potentially lead to a flawed or incomplete set of underlying assumptions about the outbreak's causal factors. This, in turn, could lead to implementing a flawed or incomplete intervention or response strategy which could extend the duration of the outbreak, resulting in avoidable morbidity and mortality.

Self-correction in biomedical publications and the scientific impact

AIM

To analyze mistakes and misconduct in multidisciplinary and specialized biomedical journals.

METHODS

We conducted searches through PubMed to retrieve errata, duplicate, and retracted publications (as of January 30, 2014). To analyze publication activity and citation profiles of countries, multidisciplinary, and specialized biomedical journals, we referred to the latest data from the SCImago Journal and Country Rank database. Total number of indexed articles and values of the h-index of the fifty most productive countries and multidisciplinary journals were recorded and linked to the number of duplicate and retracted publications in PubMed.

RESULTS

Our analysis found 2597 correction items. A striking increase in the number of corrections appeared in 2013, which is mainly due to 871 (85.3%) corrections from PLOS One. The number of duplicate publications was 1086. Articles frequently published in duplicate were reviews (15.6%), original studies (12.6%), and case reports (7.6%), whereas top three retracted articles were original studies (10.1%), randomized trials (8.8%), and reviews (7%). A strong association existed between the total number of publications across countries and duplicate (rs=0.86, P<0.0001) and retracted items (rs=0.812, P<0.0001). A similar trend was found between country-based h-index values and duplicate and retracted publications.

CONCLUSION

The study suggests that the intensified self-correction in biomedicine is due to the attention of readers and authors, who spot errors in their hub of evidence-based information. Digitization and open access confound the staggering increase in correction notices and retractions.

Caring for children with physical disability in Kenya: potential links between caregiving and carers' physical health

BACKGROUND

The health of a carer is a key factor which can affect the well-being of the child with disabilities for whom they care. In low-income countries, many carers of children with disabilities contend with poverty, limited public services and lack assistive devices. In these situations caregiving may require more physical work than in high-income countries and so carry greater risk of physical injury or health problems. There is some evidence that poverty and limited access to health care and equipment may affect the physical health of those who care for children with disabilities. This study seeks to understand this relationship more clearly.

METHODS

A mixed methods study design was used to identify the potential physical health effects of caring for a child with moderate-severe motor impairments in Kilifi, Kenya. Qualitative data from in-depth interviews were thematically analysed and triangulated with data collected during structured physiotherapy assessment.

RESULTS

Carers commonly reported chronic spinal pain of moderate to severe intensity, which affected essential activities. However, carers differed in how they perceived their physical health to be affected by caregiving, also reporting positive benefits or denying detrimental effects. Carers focussed on support in two key areas; the provision of simple equipment and support for their children to physically access and attend school.

CONCLUSIONS

Carers of children with moderate-severe motor impairments live with their own physical health challenges. While routine assessments lead to diagnosis of simple musculoskeletal pain syndromes, the overall health status and situation of carers may be more complex. As a consequence, the role of rehabilitation therapists may need to be expanded to effectively evaluate and support carers' health needs. The provision of equipment to improve their child's mobility, respite care or transport to enable school attendance is likely to be helpful to carers and children alike.

The incremental effect of psychosocial workplace factors on the development of neck and shoulder disorders: a systematic review of longitudinal studies

BACKGROUND

To systematically analyse evidence on the incremental effect of work-related psychosocial risk factors on the development of neck and shoulder disorders, as reported in longitudinal studies.

METHODS

A systematic literature search was conducted in three data bases (MEDLINE, EMBASE, and PsychINFO) until May 2009. The quality assessment leading to a methodological quality score of the included studies was conducted by two independent reviewers using a standardised checklist. Criteria for the evaluation of evidence were established. Heterogeneity analyses were conducted.

RESULTS

Altogether 18 prospective longitudinal studies were included in the analysis. Potential psychosocial risk factors were mainly based on the job demand control (support) model by Karasek (1998). Study results were too heterogeneous to deduce pooled risk estimates. But the weight of evidence was strong for an incremental effect of job demands, job control, social support, and job strain, on the development of neck and/or shoulder disorders.

CONCLUSION

While we found evidence for an incremental effect of different psychosocial work factors (in addition to the effect of physical job factors), these results have to be interpreted carefully in order to support the notion that psychological factors can have an independent causal influence on the development of musculoskeletal disorders. Nevertheless, our findings are important for the development of preventive strategies, as they stress the need for preventive approaches that tackle both physical and psychosocial factors. Future research is warranted to consolidate and strengthen the results of this review.

Predictors of incident and persistent neck/shoulder pain in Iranian workers: a cohort study

Background

Pain in the neck and shoulder has been linked with various psychosocial risk factors, as well as with occupational physical activities. However, most studies to date have been cross-sectional, making it difficult to exclude reverse causation. Moreover, they have been carried out largely in northern Europe, and the relationship to psychosocial factors might be different in other cultural environments.

Methods

To explore causes of neck/shoulder pain, we carried out a longitudinal study in Iranian nurses and office workers. Participants (n  = 383) completed a baseline questionnaire about neck/shoulder pain in the past month and possible risk factors, and were again asked about pain 12 months later. Associations with pain at follow-up were explored by Poisson regression and summarised by prevalence rate ratios (PRRs).

Results

After adjustment for other risk factors, new pain at follow-up was more frequent in office workers than nurses (PRR 1.9, 95%CI 1.3–2.8), among those with worst mental health (PRR 1.8, 95%CI 1.0–3.0), in those who reported incentives from piecework or bonuses (PRR1.4, 95%CI 1.0–2.0), and in those reporting job dissatisfaction (PRR 1.5, 95%CI 1.0–2.1). The strongest predictor of pain persistence was somatising tendency.

Conclusions

Our findings are consistent with a hazard of neck/shoulder pain from prolonged use of computer keyboards, although it is possible that the association is modified by health beliefs and expectations. They also indicate that the association of low mood with neck/shoulder pain extends to non-European populations, and is not entirely attributable to reverse causation. Psychosocial aspects of work appeared to have relatively weak impact.

Risk factors for musculoskeletal disorders among farm owners and farm workers: a systematic review

BACKGROUND

A systematic review was undertaken to establish risk factors for the development of musculoskeletal disorders (MSDs) among farmers.

METHODS

Comprehensive electronic searches of Pubmed, Web of Science, CINAHL, SCOPUS, EMBASE, Agris Database, and Cochrane Library were carried out using a battery of key words for MSDs and farmers. The studies methods quality was assessed using a standardized checklist.

RESULTS

Thirty-three studies fulfilled the inclusion criteria. The median method score was 65% of the maximum attainable score, resulting in 15 studies of higher methodological. Risks were categorized into: Work characteristics (n = 11), personal characteristics (n = 5), and psychosocial factors (n = 5). Spinal MSD risk factors include exposure to working in tree crops, vibration, postural load, being an owner operator, age, education beyond high school, suffering from asthma or depression, having <8 hr nightly sleep, bad quality sleep, and geographic location. Upper extremity MSD risk factors include being an owner operator, dust with pig workers, numbness and coldness in younger milkers and numbness in milkers >43 years, age, and body height in dairy farmers. Lower extremity MSD risk factors include, duration of farming ≥10 years, working >5 hr daily in animal barns, milking >40 cows, years as a dairy farmer, farm work, age, body mass, and female gender.

CONCLUSIONS

In exploring risk factors the spine was the most researched body region, followed by lower and upper extremity. Given the variance between studies, it is recommended that future studies focus on specific types of farmers and should explore specific exposures for specific body parts using standardized case definitions.

Musculoskeletal pain and overuse syndromes in adult acquired major upper-limb amputees

OBJECTIVES

(1) To compare the prevalence of self-reported musculoskeletal pain in upper-limb amputees (ULAs) in Norway with that of a control group drawn from the Norwegian general population; (2) to describe musculoskeletal pain bothersomeness in ULAs; (3) to estimate the association between prosthesis wear and self-reported musculoskeletal pain in ULAs; and (4) to describe the occurrence of musculoskeletal overuse syndromes in a sample of ULAs.

DESIGN

Cross-sectional study: postal questionnaires and clinical examinations.

SETTING

Norwegian ULA population. Clinical examinations performed at 3 clinics.

PARTICIPANTS

Questionnaires: population-based amputee sample (n=224; 57.4% response rate). Random control sample (n=318; 33.1% response rate). Clinical examinations: combined referred sample and convenience sample (n=70; 83.3% of those invited). Survey inclusion criteria: adult, resident in Norway and mastering Norwegian (amputees and controls), acquired major upper-limb amputation (amputees only).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Self-reported musculoskeletal pain and pain bothersomeness. Self-reported pain in prosthesis wearers and nonwearers. Clinically assessed diagnoses of musculoskeletal overuse syndromes.

RESULTS

Self-reported musculoskeletal pain was more frequent in ULAs than in the control group except for lower back pain. In ULAs, 57.0% reported neck/upper back pain (odds ratio [OR]=2.56; 95% confidence interval [CI], 1.64-3.98), and 58.9% reported shoulder pain (OR=4.00; 95% CI, 2.51-6.36). The percentage difference for arm pain was 24.8% (P<.001). All pain was reported as bothersome. We found no difference in pain prevalence between prosthesis wearers and nonwearers. Musculoskeletal overuse syndromes were found in 6.1% to 24.2% of ULAs, depending on diagnosis and case-definition criteria.

CONCLUSIONS

Upper-limb loss increases the risk of self-reported musculoskeletal pain in the neck/upper back, shoulders, and in the remaining arm. Prosthesis wear does not prevent musculoskeletal pain. Further studies should be conducted to investigate the effects of prosthesis wear and possible preventive measures, and to ascertain our preliminary prevalence estimates of overuse syndromes.

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.

Upper body quadrant pain in bus drivers

The aims of this study were to evaluate the prevalence of upper body quadrant pain among Israeli professional urban bus drivers and to evaluate the association between individual, ergonomic, and psychosocial risk factors and occurrence of neck pain. Three hundred and eighty-four male urban bus drivers were consecutively enrolled in the study. Data pertaining to work-related ergonomic and psychosocial stress factors were collected. The 12-month prevalence of neck pain was 21.2%, followed by shoulder: 14.7%, upper back: 8.3%, elbow: 3.0%, and wrist: 3.0% pain. Prevalence of neck pain was associated with uncomfortable seats (odds ratio; OR [95% confidence interval; CI]: 2.2 [1.2-4.3], back support (2.3 [1.2-4.2]), and steering wheel (2.2 [1.1-4.5]). Drivers with neck pain reported significantly higher prevalence of pain in the upper back (OR [95% CI]: 5.9 [2.7-12.9]), shoulders (8.1 [4.3-15.3]), and wrists (7.0 [2.0-21.8]) compared to drivers without neck pain. Work-related organizational stress factors were not associated with neck pain prevalence.

Risk Exposure Assessment of Dairy Parlor Workers

Modern dairy operations have evolved into a highly specialized and precise industrialized process timed critically for maximum milk production. Milking cows is a series of carefully sequenced work tasks that can be characterized as rapid, repetitive, forceful and include awkward postures of the hands, wrists, forearms, arms and shoulders. Exposure assessment using Strain Index (SI) and HAL (Hand Activity Level) was conducted in six dairy parlors at five locations throughout the Colorado region for this pilot study to evaluate the utility of these ergonomic assessment methods in dairy parlors and to estimate risk for upper extremity (UE) musculoskeletal disorders (MSDs) among dairy parlor workers. Results from our pilot study suggest that dairy parlor work is stressful to the UE with increased risk for developing MSDs.

Risk factors for work-related musculoskeletal disorders: A systematic review of recent longitudinal studies

OBJECTIVE

This systematic review was designed and conducted in an effort to evaluate the evidence currently available for the many suggested risk factors for work-related musculoskeletal disorders.

METHODS

To identify pertinent literature we searched four electronic databases (Cinahl, Embase, Medline, and The Cochrane Library). The search strategies combined terms for musculoskeletal disorders, work, and risk factors. Only case-control or cohort studies were included.

RESULTS

A total of 1,761 non-duplicated articles were identified and screened, and 63 studies were reviewed and integrated in this article. The risk factors identified for the development of work-related musculoskeletal disorders were divided and organized according to the affected body part, type of risk factor (biomechanical, psychosocial, or individual) and level of evidence (strong, reasonable, or insufficient evidence).

CONCLUSIONS

Risk factors with at least reasonable evidence of a causal relationship for the development of work-related musculoskeletal disorders include: heavy physical work, smoking, high body mass index, high psychosocial work demands, and the presence of co-morbidities. The most commonly reported biomechanical risk factors with at least reasonable evidence for causing WMSD include excessive repetition, awkward postures, and heavy lifting. Additional high methodological quality studies are needed to further understand and provide stronger evidence of the causal relationship between risk factors and work-related musculoskeletal disorders. The information provided in this article may be useful to healthcare providers, researchers, and ergonomists interested on risk identification and design of interventions to reduce the rates of work-related musculoskeletal disorders.

Bayesian aggregation versus majority vote in the characterization of non-specific arm pain based on quantitative needle electromyography

BACKGROUND

Methods for the calculation and application of quantitative electromyographic (EMG) statistics for the characterization of EMG data detected from forearm muscles of individuals with and without pain associated with repetitive strain injury are presented.

METHODS

A classification procedure using a multi-stage application of Bayesian inference is presented that characterizes a set of motor unit potentials acquired using needle electromyography. The utility of this technique in characterizing EMG data obtained from both normal individuals and those presenting with symptoms of "non-specific arm pain" is explored and validated. The efficacy of the Bayesian technique is compared with simple voting methods.

RESULTS

The aggregate Bayesian classifier presented is found to perform with accuracy equivalent to that of majority voting on the test data, with an overall accuracy greater than 0.85. Theoretical foundations of the technique are discussed, and are related to the observations found.

CONCLUSIONS

Aggregation of motor unit potential conditional probability distributions estimated using quantitative electromyographic analysis, may be successfully used to perform electrodiagnostic characterization of "non-specific arm pain." It is expected that these techniques will also be able to be applied to other types of electrodiagnostic data.

Musculoskeletal injuries description of an under-recognized injury problem among military personnel

INTRODUCTION

Although injuries are recognized as a leading health problem in the military, the size of the problem is underestimated when only acute traumatic injuries are considered. Injury-related musculoskeletal conditions are common in this young, active population. Many of these involve physical damage caused by micro-trauma (overuse) in recreation, sports, training, and job performance. The purpose of this analysis was to determine the incidence of injury-related musculoskeletal conditions in the military services (2006) and describe a standardized format in which to categorize and report them.

METHODS

The subset of musculoskeletal diagnoses found to be injury-related in previous military investigations was identified. Musculoskeletal injuries among nondeployed, active duty service members in 2006 were identified from military medical surveillance data. A matrix was used to report and categorize these conditions by injury type and body region.

RESULTS

There were 743,547 injury-related musculoskeletal conditions in 2006 (outpatient and inpatient, combined), including primary and nonprimary diagnoses. In the matrix, 82% of injury-related musculoskeletal conditions were classified as inflammation/pain (overuse), followed by joint derangements (15%) and stress fractures (2%). The knee/lower leg (22%), lumbar spine (20%), and ankle/foot (13%) were leading body region categories.

CONCLUSIONS

When assessing the magnitude of the injury problem in the military services, injury-related musculoskeletal conditions should be included. When these injuries are combined with acute traumatic injuries, there are almost 1.6 million injury-related medical encounters each year. The matrix provides a standardized format to categorize these injuries, make comparisons over time, and focus prevention efforts on leading injury types and/or body regions.

Neck disorders among construction workers: understanding the physical loads on the cervical spine during static lifting tasks

In this study a common yet very strenuous construction work activity, was evaluated biomechanically by studying electromyography (EMG) of the major neck muscles. The muscles studied were the sternocleidomastoid and the upper trapezius. Fifteen healthy participants (10 males and 5 females) with no history of musculoskeletal abnormalities participated in this study. The participants lifted 25%, 50%, and 75% of their maximum shoulder height static strength at neutral, maximally flexed, and maximally extended neck postures. The weight lifted as well as the neck posture significantly affected the activities of the neck muscles. Increase in the weight increased the activation of the neck muscles. The sternocleidomastoid muscle was most active at the extended neck posture, while the upper trapezius muscle was most active at the flexed neck posture. The results of this study indicate that the neck muscles play an active role during lifting and holding tasks at shoulder height. Thus, such tasks could be probable risk factors associated with neck disorders prevalent among construction workers.

Risk of musculoskeletal disorders among females and males in repetitive/constrained work

This paper combines epidemiological data on musculoskeletal morbidity in 40 female and 15 male occupational groups (questionnaire data 3720 females, 1241 males, physical examination data 1762 females, 915 males) in order to calculate risk for neck and upper limb disorders in repetitive/constrained vs. varied/mobile work and further to compare prevalence among office, industrial and non-office/non-industrial settings, as well as among jobs within these. Further, the paper aims to compare the risk of musculoskeletal disorders from repetitive/constrained work between females and males. Prevalence ratios (PR) for repetitive/constrained vs. varied/mobile work were in neck/shoulders: 12-month complaints females 1.2, males 1.1, diagnoses at the physical examination 2.3 and 2.3. In elbows/hands PRs for complaints were 1.7 and 1.6, for diagnoses 3.0 and 3.4. Tension neck syndrome, cervicalgia, shoulder tendonitis, acromioclavicular syndrome, medial epicondylitis and carpal tunnel syndrome showed PRs > 2. In neck/shoulders PRs were similar across office, industrial and non-office/non-industrial settings, in elbows/hands, especially among males, somewhat higher in industrial work. There was a heterogeneity within the different settings (estimated by bootstrapping), indicating higher PRs for some groups. As in most studies, musculoskeletal disorders were more prevalent among females than among males. Interestingly, though, the PRs for repetitive/constrained work vs. varied/mobile were for most measures approximately the same for both genders. In conclusion, repetitive/constrained work showed elevated risks when compared to varied/mobile work in all settings. Females and males showed similar risk elevations. This article enables comparison of risk of musculoskeletal disorders among many different occupations in industrial, office and other settings, when using standardised case definitions. It confirms that repetitive/constrained work is harmful not only in industrial but also in office and non-office/non-industrial settings. The reported data can be used for comparison with future studies.

Naturopathic treatment of rotator cuff tendinitis among Canadian postal workers: a randomized controlled trial

OBJECTIVE

To explore the effectiveness of naturopathic care (NC) on rotator cuff tendinitis using a prospective randomized clinical trial design.

METHODS

Canadian postal workers with rotator cuff tendinitis for a duration of >6 weeks were randomized to receive NC (n = 43) or standardized physical exercises (PEs; n = 42) over 12 weeks. Participants in the NC group received dietary counseling, acupuncture, and Phlogenzym (2 tablets 3 times/day). The PE intervention group received passive, active-assisted, and active range of motion exercises and matched placebo. The primary outcome measure was the Shoulder Pain and Disability Index (SPADI), and secondary outcomes were the pain visual analog scale (VAS), Short Form 36 (SF-36), Measure Yourself Medical Outcomes Profile (MYMOP), and shoulder maximal range of motion. Participants and assessors were blinded to group and placebo allocation.

RESULTS

Seventy-seven participants (87%) completed >or=8 weeks of the trial. Final total SPADI scores decreased by 54.5% (P < 0.0001) in the NC group and by 18% (P = 0.0241) in the PE group. Between-group differences in changes to SPADI scores showed statistically significant decreases in shoulder pain and disability in the NC group compared with the PE group (P < 0.0001). Significant differences between groups were also observed in the pain VAS, MYMOP, SF-36, and shoulder extension, flexion, and abduction, with the NC group showing superiority in each outcome. No serious adverse reactions were observed.

CONCLUSION

NC and PE provided significant improvements, with greater improvement in shoulder function in the NC group compared with the PE group. Statistically significant improvements in quality of life measures were observed in the NC group as compared with the PE group.

Manifestations of shoulder fatigue in prolonged activities involving low-force contractions

Shoulder fatigue has been suggested to be a useful risk indicator for shoulder disorders in repetitive, low-force work tasks. In contrast to high-force or purely isometric tasks, it is unclear whether measurable fatigue develops in realistic low-force work. The question addressed in this review was: 'Is there evidence of objective signs of fatigue in the shoulder region in realistic, low-force work tasks?' Studies on objective measures of fatigue applied in realistic low-force work tasks were systematically reviewed, using a task duration of more than 1 h and an intensity level of less than 20% maximum voluntary contraction (MVC) for the median trapezius activation level as inclusion criteria. Thirteen studies were found to fulfil the criteria. All these studies addressed fatigue-related changes in the electromyographic signal in the descending part of the trapezius muscle. Seven did find a combination of frequency decrease and amplitude increase over time, which is generally considered as an objective manifestation of fatigue. Thus, there is evidence of objective signs of fatigue in some of the realistic, low-force tasks. The intensity level appeared to be a main determinant here. In the studies demonstrating signs of fatigue an intensity level of 15%MVC or more was used, while the intensity level in the studies with a negative result was generally lower.

A longitudinal analysis of the effects of a preventive exercise programme on the factors that predict shoulder pain in construction apprentices

Construction apprentices are at risk for developing shoulder pain with increasing exposure to repetitive overhead work. Risk may decrease if shoulder biomechanics are optimised and if risk factors that contribute to shoulder pain onset are identified. This prospective cohort study examined demographic and work-related factors and shoulder pain onset over 2 years in a cohort of 240 construction apprentices. Approximately 50% of the sample (n=117) performed a home exercise programme intended to have a protective effect, while the other 50% served as controls. The proportion of new-onset shoulder pain in the control group was higher than in the exercise group. Regression analysis identified four factors related to new-onset shoulder pain: previous neck pain; working in hot, cold or humid conditions; subject height; and bending and twisting the back. This information may assist employers and workers in preventing shoulder pain. By knowing factors predictive of shoulder pain development in construction workers, employers can take measures to protect workers and may secondarily decrease medical expenses and maintain productivity. Previous neck pain, working in extreme environmental conditions and being shorter all increased a worker's risk of developing shoulder pain. Exercises to optimise shoulder biomechanics have a small effect on preventing shoulder pain development.

Management of work-relevant upper limb disorders: a review

BACKGROUND

Upper limb disorders (ULDs) are clinically challenging and responsible for considerable work loss. There is a need to determine effective approaches for their management.

AIM

To determine evidence-based management strategies for work-relevant ULDs and explore whether a biopsychosocial approach is appropriate.

METHODS

Literature review using a best evidence synthesis. Data from articles identified through systematic searching of electronic databases and citation tracking were extracted into evidence tables. The information was synthesized into high-level evidence statements, which were ordered into themes covering classification/diagnosis, epidemiology, associations/risks and management/treatment, focusing on return to work or work retention and taking account of distinctions between non-specific complaints and specific diagnoses.

RESULTS

Neither biomedical treatment nor ergonomic workplace interventions alone offer an optimal solution; rather, multimodal interventions show considerable promise, particularly for occupational outcomes. Early return to work, or work retention, is an important goal for most cases and may be facilitated, where necessary, by transitional work arrangements. The emergent evidence indicates that successful management strategies require all the players to be on side and acting in a coordinated fashion; this requires engaging employers and workers to participate.

CONCLUSIONS

The biopsychosocial model applies: biological considerations should not be ignored, but psychosocial factors are more influential for occupational outcomes. Implementation of interventions that address the full range of psychosocial issues will require a cultural shift in the way the relationship between upper limb complaints and work is conceived and handled. Dissemination of evidence-based messages can contribute to the needed cultural shift.

Qigong and exercise therapy in patients with long-term neck pain: a prospective randomized trial

STUDY DESIGN

A randomized, controlled, multicenter trial: 1-year follow-up.

OBJECTIVE

To compare the effectiveness of qigong and exercise therapy in subjects with long-term nonspecific neck pain.

SUMMARY OF BACKGROUND DATA

The evidence for the benefit of treatment programs focusing on persons with long-term, nonspecific neck pain is conflicting. Several studies have shown support for exercise therapy, but the efficacy of qigong has not been scientifically evaluated.

METHODS

A total of 122 patients were randomly assigned to receive either qigong (n = 60) or exercise therapy (n = 62). Most of them were women (70%), and the mean age was 44 years. A maximum of 12 treatments were given over a period of 3 months. Neck pain frequency and intensity, neck disability (NDI), grip strength, and cervical range of motion were recorded before and immediately after, at 6 months, and at 12 months after the treatment period. Changes in outcome variables were analyzed and dichotomized as improved or unchanged/deteriorated.

RESULTS

Clinical and demographic characteristics were similar among groups at baseline. No differences were found between the 2 interventions: qigong and exercise therapy. Both groups significantly improved immediately after treatment and this was maintained at the 6- and 12-month follow-ups in 5 of 8 outcome variables: average neck pain in the most recent week, current neck pain (with exception for immediately after treatment period), neck pain diary, NDI, and cervical range of motion in rotation.

CONCLUSION

These results indicate that treatments including supervised qigong or exercise therapy resulting in reduced pain and disability can be recommended for persons with long-term nonspecific neck pain.

Regional pain syndrome: clinical characteristics, mechanisms and management

Regional soft-tissue complaints are commonplace, and they usually relate to a disease process, such as strain, inflammation or degeneration of a muscle, tendon or related muscle-tendon unit. The clinical features and investigations of the causative processes of these complaints are characteristic, and outcomes to treatments are usually predictable and satisfactory. Regional pain syndromes are different: these syndromes present with regional pain and tenderness, and other sensory symptoms unaccounted for by a simple musculoskeletal mechanistic explanation. Approved classification criteria for regional pain syndromes are lacking, and these syndromes are poorly understood and frequently misdiagnosed. Regional pain syndromes often occur after injury and overlap extensively with other musculoskeletal pain syndromes, in terms of clinical signs and symptoms. The clinician and patient are often confused about the nature of the problem and routine treatments directed to putative tissue damage will fail. Review of the epidemiology of regional pain syndromes combined with knowledge of other similar pain syndromes has enabled an evolving understanding of the condition. The musculoskeletal and central nervous systems both contribute to regional pain syndromes, through spine-related pain mechanisms and central sensitization, respectively. The patient's emotional state, particularly the effect on pain modulation, links these two systems.

Public health perspective--how to improve the musculoskeletal health of the population

Musculoskeletal disorders are the most common cause of long-term sick leave in several western countries and individuals with chronic musculoskeletal pain score very low on health status measurements. Musculoskeletal health is multidimensional and is best understood from a biopsychosocial perspective. Body structure and function interacts with personal and environmental factors, affecting the ability to perform activities and participate in society. Interventions aimed at the whole population must attend to the underlying causes of musculoskeletal disorders and promote a healthy lifestyle. Safe environments and activities could reduce the risk of traumatic events and also make participation possible for those with a disability. Public beliefs about musculoskeletal symptoms and consequences need to be changed in order to minimise fear and avoidance, which, together with other psychosocial factors, could lead to chronicity. Public awareness and identification of those at risk for the development of musculoskeletal problems could lead to early and properly timed management.

Occupational disorders: non-specific forearm pain

Work-related upper limb disorder is a non-specific diagnosis for pain in the hand, wrist or, in particular, forearm once more discrete clinical conditions such as epicondylitis, tenosynovitis and carpal tunnel syndrome have been excluded. The pathophysiology of the condition is uncertain, although it is normally held to be related to an ergonomic incident. Ergonomic factors either at work or at home remain important and are discussed. Initial management is based on modification of ergonomics with appropriate periods of rest and job rotation. Treatment, however, remains somewhat unfocused and unsatisfactory. Much can be learnt from the ergonomic study of musicians, where the condition is perhaps at its most refined. Medico-legal aspects and recent thoughts on pathogenesis are also discussed.

Are deficiencies in manual tracking associated with upper extremity cumulative trauma disorders?

OBJECTIVES

To examine the reliability of manual tracking performance and its association with impairment and disability in individuals symptomatic of an upper extremity cumulative trauma disorder (CTD).

METHODS

Volunteer and physician referred subjects (100 control, 140 CTD) tracked a target cursor moving quasi-randomly using a hand-held stylus interfaced with a digitizing tablet. Impairment was physician-rated and the Disability of the Arm, Shoulder and Hand questionnaire measured disability. Subsamples of 25 subjects per group were tested on three occasions.

RESULTS

Reliability of tracking performance was excellent (ICC > or = 0.88) and sensitivity was 81%. Performance was superior in controls (p < 0.001) and deteriorated as a function of impairment level (p < 0.001). Tracking and impairment rating explained 65% of the disability score.

CONCLUSIONS

Tracking performance may be an important outcome for monitoring change over time and the impact of a CTD on function in everyday activities.

Management of musculoskeletal pain

Chronic musculoskeletal pain is a major public health problem affecting about one third of the adult population. Pain is often present without any specific findings in the musculoskeletal system and a strictly biomedical approach could be inadequate. A biopsychosocial model could give a better understanding of symptoms and new targets for management. Identification of risk factors for chronicity is important for prevention and early intervention. The cornerstones in management of chronic non-specific, and often widespread, musculoskeletal pain are non-pharmacological. Physical exercise and cognitive behavioral therapy, ideally in combination, are first line treatments in e.g. chronic low back pain and fibromyalgia. Analgesics are useful when there is a specific nociceptive component, but are often of limited usefulness in non-specific or chronic widespread pain (including fibromyalgia). Antidepressants and anticonvulsants could be of value in some patients but there is a need for more knowledge in order to give general recommendations.

Development of fatigue and discomfort in the upper trapezius muscle during light manual work

Optimization of the temporal aspects of task design requires a better understanding of the development of muscle fatigue in the neck and shoulder region over time. The objective of the study was to investigate this in two production companies and to determine the relationship between objective and subjective estimates of fatigue. Indicators of fatigue were obtained through electromyography (EMG) during test contractions and ratings of perceived discomfort. EMG amplitude increased during the day in both case studies while mean power frequency decreased only in one case. In both cases, a more detailed frequency analysis of the EMG signals showed an increase in lower frequency power accompanied by a decrease in higher frequency power. Local perceived discomfort in the neck and shoulder increased over the course of the day in both cases. However, no clear relationship between perceived discomfort and objective indicators of fatigue was found. Obtaining sufficient sensitivity to detect effects of temporal aspects of task design probably requires complementary or more refined methods (e.g. EMG arrays, mechanomyography).