Gender differences in workers with identical repetitive industrial tasks: exposure and musculoskeletal disorders

Musculoskeletal disorders and ergonomics in dermatologic surgery: a survey of Mohs surgeons in 2010

BACKGROUND

Dermatologic surgeons perform numerous procedures that put them at risk of developing work-related musculoskeletal disorders.

OBJECTIVE

To study the prevalence of work-related musculoskeletal disorders and role of ergonomics in dermatologic surgery.

METHODS AND MATERIALS

A survey study was sent to members of the American College of Mohs Surgery in 2010. The main outcome measures were survey responses relating to surgeon demographics, musculoskeletal symptoms, workstyle habits and attitudes, and ergonomic practices.

RESULTS

Ninety percent of respondents reported some type of musculoskeletal symptoms or injuries. The most common complaints were neck, lower back, shoulder, and upper back pain. Most respondents were not using ergonomic modifications in their practice.

CONCLUSION

Mohs surgeons have a high prevalence of musculoskeletal disorders. Symptoms present early and persist throughout the careers of Mohs surgeons. The nature of the occupation leaves the surgeon vulnerable to injury. Ergonomic modifications in behavior and workplace are recommended to reduce pain and injury to surgeons.

Prevalence of musculoskeletal disorders and job exposure in Taiwan oyster shuckers

BACKGROUND

Oyster shucking is characterized by long hours of static work, awkward working posture, and highly repetitive hand/wrist motion. The objectives of this study were to investigate the prevalence of musculoskeletal discomfort and kyphosis in oyster shuckers in Taiwan as well as the biomechanical features of oyster shucking.

METHODS

The Chinese version of the Standardized Nordic Musculoskeletal Questionnaire was successfully collected from 234 oyster shuckers. The characteristics of workstation, hand/wrist motion angles, and muscular exertion in shucking oysters were recorded. Measurements to identify kyphosis were also taken from the subjects and a control group.

RESULTS

Among the participated oyster shuckers, low back (75.2%), hand/wrist (60.3%), shoulder (44.0%), and elbow (27.8%) discomfort were reported most frequently. The prevalence of low back discomfort in oyster shuckers was higher than various groups of workers who need long hours of seated position. Those who worked on tables had fewer musculoskeletal complaints in shoulder and elbow (P < 0.05) than those not. Additionally, oyster shuckers were more prone to kyphosis than the general population (P < 0.001).

CONCLUSIONS

Oyster shuckers are observed to have high prevalence of musculoskeletal discomfort and kyphosis. Introduction of ergonomic design to oyster shucking workshops is strongly suggested.

A critical review on physical factors and functional characteristics that may explain a sex/gender difference in work-related neck/shoulder disorders

The objective of this paper is to critically review recent literature on physical and functional sex/gender (s/g) differences, with focus on physical determinants associated with neck/shoulder musculoskeletal injuries. It is well known that there are s/g differences in anthropometrical and functional body characteristics (e.g. size and strength). However, s/g differences may be wrongly attributed if data analysis does not include appropriate corrections (e.g. by strength for endurance). Recent literature on motor control shows that there may indeed be s/g differences in muscle coordination and movement strategies during upper limb tasks that are not currently explained by methodological inadequacies. Moreover, recent studies have shown differences between men and women in sensory hypersensitivity characteristics associated with neck/shoulder injuries. Taken together, the literature points to the importance of accounting for possible s/g differences at all levels of the biopsychosocial system in order to better understand sex- and gender-specific issues relevant to workplace health.

PRACTITIONER SUMMARY

This article critically reviews recent literature and a conceptual model highlighting s/g differences in physical and functional characteristics related to neck/shoulder musculoskeletal disorders (NSMSD). Findings have implications on understanding how personal factors may affect NSMSD risk. With better understanding, practitioners can make more appropriate decisions to prevent work-related NSMSD.

Work organisation and gender among hospital cleaners in Quebec after the merger of 'light' and 'heavy' work classifications

In Québec, Canada, cleaning tasks were once divided into 'light' or 'heavy' cleaning, assigned respectively to women and men. These categories are being merged; in principle, both genders are assigned the same tasks. Activity analysis using observations and interviews examined work activity of male and female cleaners in two hospitals. In one hospital, work activity could be compared before (time 1) and after the work reorganisation (time 2). Some gender segregation of tasks appeared to have persisted at time 2, in both hospitals. Some route assignments contained components that were difficult for all cleaners, especially women of average strength. Only about one-third of the recommendations for improvement made at time 1 had been carried out by time 2, 12 years later. In a low-status job, it may be hard to meet equality, health and efficiency goals because commitment to improving equipment and worksite design may be lacking.

PRACTITIONER SUMMARY

Current attempts to desegregate jobs should be accompanied by attention to physical job demands in order to protect employee health and access to equal employment. The study also shows the need to follow up ergonomic interventions, particularly in low-status jobs such as cleaning, where recommendations can be forgotten.

Age- and sex-related differences for electromyography gaps during daily activity and a discrete task

Temporal patterns of quiescent electromyography termed 'gaps' were investigated in young and old men and women for a discrete task and daily activity. Gaps in women (1.3±3.2) and old adults (1.5±3.4) were fewer compared with men (4.7±6.7) and young adults (4.6±6.9) for the discrete task (p<0.001). Gap duration was shorter for women (0.1±0.2s) and old adults (0.1±0.3s) compared with men (0.2±0.3s) and young adults (0.2±0.2s) (p<0.01). For daily activity, gap number was similar with age, but gap duration and percentage of total time occupied by gaps were less in old compared with young adults (50%), and in women compared with men (43%) (p<0.001). Results suggest gap activity is sensitive to type and duration of activity and that old adults and women demonstrate less quiescent electromyography than young adults and men.

Effects of gender in amyotrophic lateral sclerosis

BACKGROUND

There is evidence that amyotrophic lateral sclerosis (ALS), also known as motor neuron disease (MND), is more common in men than in women and that gender influences the clinical features of the disease. The causes of this are unknown.

OBJECTIVE

This review examines the gender differences that are found in ALS and postulates reasons for these differences.

METHODS

A literature review of PubMed (with no date limits) was performed to find information about gender differences in the incidence, prevalence, and clinical features of ALS, using the search terms ALS or MND and gender or sex, ALS prevalence, and SOD1 mice and gender. Articles were reviewed for information about gender differences, together with other articles that were already known to the authors.

RESULTS

The incidence and prevalence of ALS are greater in men than in women. This gender difference is seen in large studies that included all ALS patients (sporadic and familial), but is not seen when familial ALS is studied independently. Men predominate in the younger age groups of patients with ALS. Sporadic ALS has different clinical features in men and women, with men having a greater likelihood of onset in the spinal regions, and women tending to have onset in the bulbar region. Gender appears to have no clear effect on survival. In animals with superoxide dismutase 1 (sod1) mutations, sex does affect the clinical course of disease, with earlier onset in males. Possible reasons for the differences in ALS between men and women include different exposures to environmental toxins, different biological responses to exogenous toxins, and possibly underlying differences between the male and female nervous systems and different abilities to repair damage.

CONCLUSIONS

There is a complex interaction between gender and clinical phenotypes in ALS. Understanding the causes of the gender differences could give clues to processes that modify the disease.

Head movements during two computer work tasks assessed by accelerometry

We investigated whether potential differences in head inclinations and accelerations for two highly similar computer work tasks could be detected using (1) a triaxial accelerometer and (2) a simulated uniaxial accelerometer. Ten subjects' head movements were registered with a triaxial accelerometer system for two similar document-management tasks at their work place: a fully electronic document-management task and one also involving paper documents. In situations where head movements were small, a triaxial accelerometer was able to discriminate between the different degrees of static work of the neck in terms of range of head inclinations and accelerations. A difference in head acceleration was also found by using a simulated uniaxial accelerometer. Thus, in terms of head movement and for work similar to this office work, potential dynamic differences in observationally similar work tasks can be investigated by using a triaxial accelerometer. For acceleration alone, a uniaxial accelerometer can also be used.

A review of direct neck measurement in occupational settings

No guidelines are available to orient researchers on the availability and applications of equipment and sensors for recording precise neck movements in occupational settings. In this study reports on direct measurements of neck movements in the workplace were reviewed. Using relevant keywords two independent reviewers searched for eligible studies in the following databases: Cinahal, Cochrane, Embase, Lilacs, PubMed, MEDLINE, PEDro, Scopus and Web of Science. After applying the inclusion criteria, 13 articles on direct neck measurements in occupational settings were retrieved from among 33,666 initial titles. These studies were then methodologically evaluated according to their design characteristics, exposure and outcome assessment, and statistical analysis. The results showed that in most of the studies the three axes of neck movement (flexion-extension, lateral flexion and rotation) were not simultaneously recorded. Deficiencies in available equipment explain this flaw, demonstrating that sensors and systems need to be improved so that a true understanding of real occupational exposure can be achieved. Further studies are also needed to assess neck movement in those who perform heavy-duty work, such as nurses and electricians, since no report about such jobs was identified.

How do children perceive health to be affected by domestic water carrying? Qualitative findings from a mixed methods study in rural South Africa

BACKGROUND

Nearly 50% of South African children lack access to clean safe water and many regularly carry water loads. The health effects of carrying water have not been well researched or considered when estimating the burden of disease due to suboptimal water supply. Improved access to safe water has potential to create important health and economic benefits, by reducing childhood exposure to risk factors for injury or disease. The aim of this study was to identify which domains of health children perceive as affected by water carrying.

METHODS

Qualitative research was used within a broader mixed methods design to investigate children's perceptions about health and water carrying in Limpopo Province, South Africa. Qualitative data from eight semi-structured interviews and three 'natural group meetings', involving a sample of 30 children, were analysed using the framework approach of Ritchie and Spencer. The results were mapped to the International Classification of Functioning Disability and Health (ICF).

RESULTS

Children broadly conceptualize and describe health to include the functions they perform and activities in which they participate. They perceived water carrying as impacting upon health in various ways, for example to make life better by facilitating water usage, or to make life worse through accidents and pain. Children's accounts demonstrate that they can identify and explain complex interactions between activities, participation and health.

CONCLUSIONS

The ICF framework facilitates the communication of children's perceptions of health and of relationships between health and water carrying. The model thus derived from their views incorporates not only commonly accepted conceptualizations of health condition, body structure and physiological function, but also of functioning through activities and social participation. Children's accounts suggest a possible association between water carrying and symptoms typical of musculoskeletal disorders. However, further research into the strength of association between water carrying and musculoskeletal disorders is needed.

Pressure pain sensitivity maps of the neck-shoulder and the low back regions in men and women

Background

Musculoskeletal pain in the low back and neck-shoulder regions is a major problem among the working population all over the world. The prevalence of musculoskeletal pain is found to be higher among women. Women also have lower pressure pain thresholds (PPTs) than men. Pressure pain topography aims at mapping the spatial distribution of PPT within a muscle in an attempt to track changes in mechanical sensitivity. In order to assess gender differences in the pain topography, it is necessary to map the distribution in both healthy men and women. The aim of this study was to assess PPT maps from the cervico-thoracic and lumbar regions in men and women.

Methods

Eleven men and eleven women without any known musculoskeletal disorders participated in the study. PPT was measured twice at 36 points over the trapezius muscle of the dominant arm, at 36 points over the trapezius muscle on the contralateral side and at 12 points over the spine between the left and right trapezius. Further, 11 points were measured over the erector spinae muscle on the left side of the spine between the first and the fifth lumbar vertebrae, 11 on the right side and 5 points on the spine itself. The measurements on each trapezius muscle were divided according to anatomical subdivisions. Three-way and two-way ANOVAs were used to analyse the differences in PPTs with the following factors: gender, locations and sub-divisions (only for cervico-thoracic region).

Results

There were no differences between left and right side in neither the cervico-thoracic nor the lumbar region, but there were (large effect) differences between the subdivisions in the trapezius with the lowest values in the upper part (P < 0.001; partial η² = 0.19). Women had (small effect) lower PPT in both cervico-thoracic and lumbar regions (P ≤ 0.001; partial η² = 0.02 for both regions), but gender had no effect on neither location nor subdivisions.

Conclusions

The pain topography was not found to be different between genders in the cervico-thoracic and lumbar regions. This study can be used as basis for further clinical studies on musculoskeletal disorders.

Field evaluation of a modified intervention for overhead drilling

Drilling holes into concrete or metal ceilings is one of the most physically demanding tasks performed in construction. The work is done overhead with rotary impact hammer drills that weigh up to 40 N. The task is associated with pain and musculoskeletal disorders at the wrist, forearm, shoulder, and back. The mechanism of injury is thought to be the high forces and non-neutral shoulder and wrist postures applied during drilling. Previously, we described a field study of a foot lever and inverted drill press intervention devices that received poor usability ratings compared with the usual method for overhead drilling based on problems with mobility and productivity. Using a participatory intervention model, feedback from construction workers (N = 13) was used to develop a new intervention design that incorporated a wheeled tripod base and a unique method of aligning the drilling column to vertical. A different group of construction workers (N = 23) evaluated usability and fatigue of the new device during their regular overhead drilling in comparison with the usual method. Four of 12 usability ratings were significantly better with the intervention device compared with the usual method. Subjective shoulder fatigue was less with the new intervention (1.1 vs. 3.3; scale 0 to 5; p < 0.001). This difference was supported by objective outcome measures; the mean hand forces during drilling were 26 N with the intervention compared with 245 N with the usual method. The percentage of time with the shoulder flexed or abducted to more than 60 degrees was less with the intervention compared with the usual method (21 vs. 40%; p = 0.007). There was significantly less head extension with the intervention compared with the usual method. There were no significant differences in overall productivity between the two methods. This study demonstrates that a new intervention device for overhead drilling has improved usability and subjective fatigue ratings compared with the usual method. These improvements are most likely due to the reduced hand forces, reduced shoulder abduction and flexion, and reduced drilling time.

Thumb postures and physical loads during mobile phone use - a comparison of young adults with and without musculoskeletal symptoms

The aim of this study was to evaluate thumb postures, thumb movements and muscle activity when using mobile phones for SMS messaging and to determine whether there were differences in these exposures (a) across various mobile phone tasks, (b) between gender and (c) between subjects with and without musculoskeletal symptoms in shoulders and upper extremities. Fifty-six young adults (15 healthy and 41 with musculoskeletal symptoms) performed a series of distinct tasks on a mobile phone. Muscular load in four forearm/hand muscles in the right arm and the right and left trapezius muscles were measured using electromyography (EMG). Thumb movements were registered using an electrogoniometer. The results showed that postures (sitting or standing) and the type of mobile phone task (holding the phone versus texting) affected muscle activity and thumb positions. Females compared to males had higher muscle activity in the extensor digitorum and the abductor pollicis longus when entering SMS messages and tended to have greater thumb abduction, higher thumb movement velocities and fewer pauses in the thumb movements. Subjects with symptoms had lower muscle activity levels in the abductor pollicis longus and tended to have higher thumb movement velocities and fewer pauses in the thumb movements compared to those without symptoms.

Associação entre características pessoais, organização do trabalho e presença de dor em funcionários de uma indústria moveleira

Os distúrbios osteomusculares relacionados ao trabalho são afecções que atingem os tecidos moles. Têm um nexo causal com fatores de risco ergonômicos e um caráter insidioso e multifatorial, apresentando como sintoma comum dores musculoesqueléticas. O objetivo deste estudo foi investigar possível associação entre características pessoais, organização do trabalho e presença de dor em funcionários de uma indústria moveleira no município de Araçatuba, SP. Foi aplicado um questionário a uma amostra de 158 funcionários de diversos setores da empresa, com questões de caráter sociodemográfico (sexo, idade), trabalhista (setor, tempo de serviço, função desempenhada e jornada de trabalho semanal), bem como sobre sintomas dolorosos musculoesqueléticos. Dor foi relatada por 58,9% dos funcionários e relacionada de maneira significativa com o sexo (p=0,0001), setor de trabalho (p=0,0021), função desempenhada (p=0,0135) e jornada de trabalho semanal (p=0,0123). A dor predominou em mulheres, dependendo do setor, da função desempenhada e da jornada de trabalho semanal. Para tentar saná-la, a maioria dos trabalhadores usa medicamentos ou adota a atitude de ignorá-la. Os resultados sugerem a necessidade de intervenção fisioterapêutica preventiva.

Risk factors for upper-extremity musculoskeletal disorders in the working population

OBJECTIVE

To assess the relative importance of personal and occupational risk factors for upper-extremity musculoskeletal disorders in the working population.

METHODS

A total of 3,710 workers (58% men) participating in a surveillance program of musculoskeletal disorders in a French region in 2002-2005 were included. Upper-extremity musculoskeletal disorders were diagnosed by 83 trained occupational physicians performing a standardized physical examination. Personal factors and work exposure were assessed by a self-administered questionnaire. Statistical associations between musculoskeletal disorders, personal, and occupational factors were analyzed using logistic regression modeling.

RESULTS

A total of 472 workers experienced at least 1 upper-extremity musculoskeletal disorder. The risk of upper-extremity musculoskeletal disorders increased with age for both sexes (P < 0.001, odds ratio [OR] < or =4.9 in men and < or =5.0 in women), and in cases of prior history of upper-extremity musculoskeletal disorders (OR 3.1 and 5.0, respectively, P < 0.001). In men, upper-extremity musculoskeletal disorders were associated with obesity (OR 2.2, P = 0.014), high level of physical demand (OR 2.0, P < 0.001), high repetitiveness of the task (OR 1.5, P = 0.027), postures with the arms at or above shoulder level (OR 1.7, P = 0.009) or with full elbow flexion (OR 1.6, P = 0.006), and high psychological demand (OR 1.5, P = 0.005). In women, upper-extremity musculoskeletal disorders were associated with diabetes mellitus (OR 4.9, P = 0.001), postures with extreme wrist bending (OR 2.0, P < 0.001), use of vibrating hand tools (OR 2.2, P = 0.025), and low level of decision authority (OR 1.4, P = 0.042).

CONCLUSION

Personal and work-related physical and psychosocial factors were strongly associated with clinically diagnosed upper-extremity musculoskeletal disorders.

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.

Equal task, equal exposure? Are men and women with the same tasks equally exposed to awkward working postures?

The aim of the study was to determine whether men and woman with equal tasks perform these tasks in the same way. Video recordings of 37 male and 43 female workers in six task groups were observed, from which data regarding frequency and duration of exposure to awkward postures were derived. These data were also compared to self-reported exposures. The results showed that when level, duration and frequency of exposure were analysed at the same time, men and women had slightly different exposure patterns. However, these differences were not found when duration and frequency were analysed separately. From the questionnaires it appeared that men and women generally report similar exposures, but they seemed to over-report their exposure compared to the observed exposures. It is concluded that gender differences in exposure to awkward postures within the same task were small at most and cannot explain the female excess in musculoskeletal symptoms.

Upper-extremity musculoskeletal symptoms and physical health related quality of life among women employed in poultry processing and other low-wage jobs in northeastern North Carolina

BACKGROUND

The purpose of this study was to evaluate the association between upper-extremity musculoskeletal symptoms (MS) and diminished physical health related quality of life (PHRQoL) in a population of women, mostly African-American working in poultry processing and other low-wage jobs in rural northeastern North Carolina.

METHODS

A cross-sectional analysis was performed on baseline data of self-reported PHRQoL and musculoskeletal symptoms for 291 poultry processing workers and 299 community comparison women. Logarithmic binomial regression was performed to assess the relationship between moderate to severe MS on low PHRQoL.

RESULTS

Prevalence of poor PHRQoL was 35.5% among poultry processing workers, and 14.7% among community comparison group. Moderate to severe upper-extremity musculoskeletal symptoms were present in 34.4% of the poultry workers and 10.7% of the comparison group. After adjusting for age and other chronic conditions, moderate to severe musculoskeletal symptoms were associated with low PHRQoL in both groups. Although the observed effect was stronger among the comparison group (adjusted prevalence ratios (95% confidence interval): poultry workers = 1.89 (1.36, 2.64), community comparison = 4.26 (2.51, 7.24), the population attributable risk percent was similar (poultry workers = 28.9, community comparison = 31.3%)) due to the higher prevalence of moderate to severe symptoms in the poultry workers.

CONCLUSIONS

Significant upper-extremity musculoskeletal symptoms were associated with poor PHRQoL among both groups of women employed in low-wage jobs. Nationwide, poultry work is over-represented by minorities and immigrants. Though challenging, we need to search for ways to improve the conditions of these women as a matter of social justice.

Physiological and psychological reactions to work in men and women with identical job tasks

Differences in physiological functioning in the hypothalamus-pituitary-adrenal cortex axis and the autonomic nervous system have been suggested to contribute to many of the health differences that may be observed between men and women as well as being relevant for the development of musculoskeletal pain. To clarify whether men and women with identical work tasks reacted differently when doing work known to induce musculoskeletal pain, ratings and physiological measurements were obtained at work start (15:30) and at the end of the workshift (22:30) on 17 men and 20 women. Men showed a larger decrease in perceived energy levels during the workshift but there were no differences between men and women as regards cortisol, adrenaline, noradrenaline, heart-rate activation, perceived stress, pain and physical exertion. In conclusion, differential physiological activation during the workshift seem to be an unlikely mechanism for explaining gender differences in pain associated with exposure to awkward and repetitive movements.