Musculoskeletal symptoms, ergonomic aspects and psychosocial factors in two different truck assembly concepts

doi:10.1016/0169-8141(93)90036-D

International Journal of Industrial Ergonomics

Volume 12, Issues 1–2, August 1993, Pages 35-48

https://doi.org/10.1016/0169-8141(93)90036-D Get rights and content

Abstract

The project was carried out as a multidisciplinary correlational study of two truck-axle assembly systems (System A and B). System A (the old system) could be characterized as an unpaced line assembly system, whereas the change to the new system, System B, involved a parallelized system with longer job cycle time. The study included all permanent assembly workers in the two systems (System A 17 workers, System B 28 workers). The purpose of this study was to evaluate the two systems with respect to ergonomic factors, psychosocial factors and self-reported musculoskeletal symptoms. The job cycles were studied by means of video observation. Each subject answered a questionnaire regarding musculoskeletal symptoms and physical and psychosocial environment. The assemblers in System B were more satisfied with the physical work environment (e.g. noise, air), but less satisfied with the psychosocial environment, and the period prevalence of musculoskeletal symptoms was not lower, compared with the assemblers in System A. Video observation techniques showed that deep forward flexion was less common, but that the work was more hand intense in System B. In System B, neck/shoulder symptoms were associated principally with physical work (load) variables, whereas low back symptoms were associated with psychosocial variables.

References (33)

I. Kuorinka et al.
Standardised Nordic questionnaires for the analysis of musculoskeletal symptoms
Applied Ergonomics
(1987)
S.J. Bigos et al.
A prospective study of work perception and psychosocial factors affecting the report of back injury
Spine
(1991)
A. Bjelle et al.
Occupational and individual factors in acute shoulder-neck disorders among industrial workers
British Journal of Industrial Medicine
(1981)
A. Burdorf et al.
Postural load and back pain of workers in the manufacturing of prefabricated concrete elements
Ergonomics
(1991)
D.B. Chaffin et al.
Occupational biomechanics
(1984)
L.J. Cronbach
Essentials of Psychological Testing
(1990)
L. Dimberg
Symptoms from the neck, shoulders and arms in an industrial population and some related problems
T. Engström et al.
Evaluation methods for assembly work and product design in radically different production systems - Results from case studies and action research in Swedish industry
M. Hagberg
Occupational shoulder and neck disorders
(1987)
U. Järvholm et al.
Intramuscular pressure and electromyography in four shoulder muscles
Journal of Orthopaedic Research
(1991)

R. Kadefors et al.

Produktionsteknisk, psykosocial och belastningsergonomisk studie av productionsarbetsplatser

Å. Kilbom et al.

An ergonomic study of notified cases of occupational musculo-skeletal disease

Å. Kilbom et al.

Ergonomisk studie av muskuloskeletala sjukdomar anmälda som arbetsskador

Å. Kilbom et al.

Work technique and its consequences for musculoskeletal disorders

Ergonomics

(1987)

I. Kuorinka et al.

Självrapportering av arbetsställningar och arbetsmetoder samt deras relation till muskuloskeletala besvär

S. Kvarnström

Occurrence of musculoskeletal disorders in a manufacturing industry, with special attention to occupational shoulder disorders

Scand. J. Rehab. Medicine

(1983)

Cited by (62)

The effectiveness of ergonomic interventions in material handling operations
2020, Applied Ergonomics
Citation Excerpt :
These findings are similar to the relatively few prior studies that measured the impact of engineering controls on reported symptoms among non-office employees, including bricklayers (Bongers et al., 2001; Luijsterburg et al., 2005) and healthcare employees (Li et al., 2004). Other studies indicated mixed or no changes in reported symptoms after ergonomic engineering intervention among delivery drivers (Devereux et al., 1997; McGlothlin et al., 1996), other construction employees (Vink et al., 1997; Van der Molen et al., 2010), and manufacturing employees (Johansson et al., 1993). This study found no significant change in reported frequency of incidents over time without controlling for reported exposures or intervention use.
This study evaluated the effectiveness of ergonomic interventions in material handling operations involving 33 employers and 535 employees from 2012 to 2017. Outcomes included employee-reported low back/upper extremity pain and safety incidents at baseline, every three months, and annually for up to two years. A total of 32.5% of employees completed at least one survey, while 13.6% completed all nine surveys over two years. Among highly exposed employees (who reported handling >= 50 lbs. > 33% of the time), upper extremity pain frequency and severity were lower among those who reported using the intervention routinely versus those that reported using their body strength alone to handle objects >= 50 lbs. After excluding from analyses one employer that used anti-fatigue mats, low back pain frequency was also significantly lower among highly exposed intervention users. In conclusion, there was some evidence that the interventions were effective in reducing employee-reported pain for highly exposed employees.
Evaluation of ergonomic approach and musculoskeletal disorders in two different organizations in a truck assembly plant
2015, International Journal of Industrial Ergonomics
Citation Excerpt :
Some advantages of a long cycle time were reported if physical and psychosocial aspects were considered in the design of the production line. The complex nature of musculoskeletal disorders means there is a need to evaluate the various elements of the ergonomic approach and consider them as a principle for designing new organization (Johansson et al., 1993; Kadefors et al., 1996; Engström et al., 1999). Reorganization of workstations for the reason of increase of production volumes were undertaken in a truck assembly plant in France.
The aim of this study was to assess the ergonomic physical exposure, organizational and psychosocial factors in a truck assembly plant for two different cycle times (11 min and 8 min). A self-reported questionnaire was applied to evaluate subjective physical exposure, organizational and psychosocial factors by operators in two organization of an assembly process. The initial cycle time was 11 min (system A) and the new was 8 min (system B). The same work and assembly tasks had to be completed in both systems. However, the organization and distribution of the tasks and workstations were reorganized. The results of the questionnaire showed that subjective estimation by the operators regarding ergonomic risk factors was better in the new organization and self-reported WR-MSDs symptoms were fewer. However, exposure to risk factors and WR-MSDs symptoms was not statistically different between two cycle times. The findings provide better understanding of how organizational changes can modify ergonomic exposure in manufacturing assembly industries. Effective interventions are thus not only engineering solutions but also organizational and administrative adaptations.
Mechanical exposure implications of rationalization: A comparison of two flow strategies in a Swedish manufacturing plant
2012, Applied Ergonomics
Citation Excerpt :
The potential advantages of parallel flow assembly, however, seem not to be universally supported by all field studies in terms of work environment impact. Some case studies show mixed results, no effect or even negative results with parallel flow assembly when compared to more conventional system designs (Bao et al., 1996; Batt and Appelbaum, 1995; Christmansson et al., 1999; Fredriksson et al., 2001; Johansson et al., 1993; Kazmierczak et al., 2005, 2007; Neumann et al., 2002; Neumann et al., 2006; Ólafsdóttir and Rafnsson, 1998). Even in terms of performance, the advantages and disadvantages of serial and parallel flow production strategies continue to be a topic of study (Neumann et al., 2006; Wallace, 2008).
The aim of this case study was to (1) investigate differences in mechanical exposure (i.e. mechanical forces arising in the body of the operator) between two production strategies: long-cycle parallelised flow assembly (OLD) and conventional serial flow assembly (NEW), and (2) estimate potential changes in job exposure as a consequence of waste reduction when rationalising a line system.
Data on postures, movements and whole body exposure were collected during an ordinary working shift, by means of video recordings synchronised to direct technical measurements of six professional operators.
The results revealed the machine paced NEW system to have slower movements with less time spent in movements of high velocity compared to the self-paced OLD system. No significant differences were found between time-median posture levels. ‘Disturbances’ in the NEW system offered lower mechanical risk exposures compared to direct assembly work. Modelling the removal of wasteful ‘disturbances’ revealed both an increase in risk-implying fast movements and decrease in recovery-implying periods at low velocity – effectively isolating a work intensification. This study helps expose the complex relationship between rationalizations and mechanical exposure for system operators.
Occupational musculoskeletal and mental health: Significance of rationalization and opportunities to create sustainable production systems - A systematic review
2011, Applied Ergonomics
This literature review aims to identify occupational musculoskeletal and mental health effects of production system rationalization as well as organizational-level measures that may improve health outcome (“modifiers” in this review). A short review of the effect of ergonomic interventions is included as background and rationalization is discussed as a theoretical concept. Indicator variables for occupational musculoskeletal and mental health and related risk factors are presented. Variables with a generalized format were allowed in the literature searches (e.g., job satisfaction and absenteeism were accepted as risk factor and health indicator, respectively), suitable for the research fields of work sociology, organization science, human resource management (HRM) and economics research.
One hundred and sixty-two studies of rationalization effects on health and risk factors and 72 organization-level modifier results were accepted into the final database. Entries were sorted by rationalization strategy and work life sector, and trends in outcome (positive, mixed, no effect, or negative effect on health and risk factors) were determined.
Rationalizations have a dominant negative effect on health and risk factors (57% negative, 19% positive); the most negative effects were found for downsizing and restructuring rationalizations in general (71 studies negative, 13 positive) and for the health care sector in particular (36 studies negative, 2 positive). The rationalization strategy High Performance Work System (HPWS) was associated with the highest fraction positive outcome studies (6 of 10 studies). Other rationalization strategies (lean practices, parallel vs. serial production and mechanization level) reported intermediate results, in part dependent on work life sector, but also on the year when studies were carried out. Worker participation, resonant management style, information, support, group autonomy and procedural justice were modifiers with favourable influence on outcome.
It is concluded that production system rationalization represents a pervasive work life intervention without a primary occupational health focus. It has considerable and mostly negative influence on worker health, but this can be reduced by attention to modifiers. The results create a basis for new priorities in ergonomic intervention research.
Association between upper extremity musculoskeletal disorders and psychosocial factors at work: A review on the job DCS model's perspective
2010, Safety and Health at Work
Over years it has been increasingly concerned with how upper extremity musculoskeletal disorders (UEMSDs) are attributed to psychosocial job stressors. A review study was conducted to examine associations between UEMSDs and psychosocial work factors, and to recommend what to consider for the associations. For studies in which the job demand-control-support (DCS) model or its variables were specifically employed, published papers were selected and reviewed. A number of studies have reported relationships between UEMSDs symptoms and psychosocial exposure variables. For example, the findings are: higher numbness in the upper extremity was significantly attributed to by less decision latitude at work; work demands were significantly associated with neck and shoulder symptoms while control over time was associated with neck symptoms; and the combination of high psychosocial demands and low decision latitude was a significant predictor for shoulder and neck pain in a female working population. Sources of bias, such as interaction or study design, were discussed. UEMSDs were shown to be associated with psychosocial work factors in various studies where the job DCS model was addressed. Nonetheless, this review suggests that further studies should be conducted to much more clarify the association between UEMSDs and psychosocial factors.
The Burden and Determinants of Neck Pain in Workers. Results of the Bone and Joint Decade 2000-2010 Task Force on Neck Pain and Its Associated Disorders
2009, Journal of Manipulative and Physiological Therapeutics
Systematic review and best evidence synthesis.
To describe the prevalence and incidence of neck pain and disability in workers; to identify risk factors for neck pain in workers; to propose an etiological diagram; and to make recommendations for future research.
Previous reviews of the etiology of neck pain in workers relied on cross-sectional evidence. Recently published cohorts and randomized trials warrant a re-analysis of this body of research.
We systematically searched Medline for literature published from 1980–2006. Retrieved articles were reviewed for relevance. Relevant articles were critically appraised. Articles judged to have adequate internal validity were included in our best evidence synthesis.
One hundred and nine papers on the burden and determinants of neck pain in workers were scientifically admissible. The annual prevalence of neck pain varied from 27.1% in Norway to 47.8% in Québec, Canada. Each year, between 11% and 14.1% of workers were limited in their activities because of neck pain. Risk factors associated with neck pain in workers include age, previous musculoskeletal pain, high quantitative job demands, low social support at work, job insecurity, low physical capacity, poor computer workstation design and work posture, sedentary work position, repetitive work and precision work. We found preliminary evidence that gender, occupation, headaches, emotional problems, smoking, poor job satisfaction, awkward work postures, poor physical work environment, and workers' ethnicity may be associated with neck pain. There is evidence that interventions aimed at modifying workstations and worker posture are not effective in reducing the incidence of neck pain in workers.
Neck disorders are a significant source of pain and activity limitations in workers. Most neck pain results from complex relationships between individual and workplace risk factors. No prevention strategies have been shown to reduce the incidence of neck pain in workers.

View all citing articles on Scopus

View full text

Musculoskeletal symptoms, ergonomic aspects and psychosocial factors in two different truck assembly concepts

Abstract

Applied Ergonomics

A prospective study of work perception and psychosocial factors affecting the report of back injury

Spine

Occupational and individual factors in acute shoulder-neck disorders among industrial workers

British Journal of Industrial Medicine

Postural load and back pain of workers in the manufacturing of prefabricated concrete elements

Ergonomics

Occupational biomechanics

Essentials of Psychological Testing

Symptoms from the neck, shoulders and arms in an industrial population and some related problems

Evaluation methods for assembly work and product design in radically different production systems - Results from case studies and action research in Swedish industry

Occupational shoulder and neck disorders

Intramuscular pressure and electromyography in four shoulder muscles

Journal of Orthopaedic Research

Produktionsteknisk, psykosocial och belastningsergonomisk studie av productionsarbetsplatser

An ergonomic study of notified cases of occupational musculo-skeletal disease

Ergonomisk studie av muskuloskeletala sjukdomar anmälda som arbetsskador

Work technique and its consequences for musculoskeletal disorders

Ergonomics

Självrapportering av arbetsställningar och arbetsmetoder samt deras relation till muskuloskeletala besvär

Occurrence of musculoskeletal disorders in a manufacturing industry, with special attention to occupational shoulder disorders

Scand. J. Rehab. Medicine