Personal, Biomechanical and Psychosocial Risk Factors for Neck Disorders in the Working Population
A. Petit Le Manac’h1, C. Ha2, J. Bodin1, E. Parot-Schinkel1, A. Ramond1, A. Leclerc2, E. Imbernon2, Y. Roquelaure1
1Laboratoire d’Ergonomie et d’Épidémiologie en Santé au Travail (LEEST) EA 4336 – Unité associée InVS, Angers, France - aupetit@chu-angers.fr
2Département Santé Travail, Institut de Veille Sanitaire (InVS), Saint-Maurice, France
AIMS:
In the general population, neck pain and dysfunction are common, affecting up to 67% of the general population at some time during their life. About one-fifth of adults previously free of pain report a new episode of neck pain in a one-year period. In workers, neck disorder (ND) is one of the important health problems. One-year prevalence rates of neck pain in occupational settings is estimated between 6 and 76%, with higher values for female workers.
Neck pain is assumed to be of multifactorial origin, with risk factors of physical, psychosocial or personal nature. According to epidemiological studies, there is evidence that neck flexion and sitting are physical risk factors for neck pain, while high quantitative job demands, low authority over decision, low skill discretion and poor social support by colleagues are important work related psychosocial risk factors. Studies concerning personal characteristics are scarce.
Using the results of epidemiological surveillance over a three-year period (between April, 2002 and April, 2005), our aim in this study was to assess the incidence and relative importance of personal and occupational risk factors for ND in a large sample of 3,710 active workers representative of the working population of the region.
METHODS:
Population: This cross-sectional study was conducted in the Loire Valley region of West-Central France. The economic structure of the region (5% of the French working population) is diversified and similar to that of most French regions. Subjects were randomly selected from workers undergoing a mandatory regularly-scheduled annual health examination between April, 2002 and April, 2005.
Outcomes: The presence of non-specific neck pain during the last 12 months and the preceding 7 days was identified using the « Nordic-style » questionnaire.
Statistical methods: Analyses were performed for the whole sample of workers using binary logistic regression modeling, which followed a three-level process consisting of univariate models (stage 1), group multivariate models (stage 2) and final multivariate model (stage 3). All models included age and gender as possible confounders.
RESULTS:
The study population comprised 3,710 workers (2,161 men (58%), 1,549 women (42%), mean age = 38.7, sd = 10.4 years) representing about 3.4‰ of the regional workforce. Length of service in the current job was high for the majority of workers, whatever the gender. Length of service was more than ten years in 55% of cases, more than two years in 81% and more than one year in 92%.
DISCUSSION:
As ND develop gradually and follow an episodic course throughout people's live, we chose to study the contribution of risk factors to the onset of ND during the preceding seven days.
The study confirms that ND were common musculoskeletal problems in workers representative of a region’s workforce. The case definition included all kinds of non- specific neck complaints (stiffs, pain, discomfort and numbness), which can explain the higher prevalence observed in comparison with the epidemiological literature.
Our results are in accordance with the multifactorial origin of ND in workers, involving older age, female gender, previous musculoskeletal disorder, working postures and poor job satisfaction. However, we didn't explored some personal factors such as previous history of neck pain, depressive, emotional symptoms or smoking.
According to the literature, ND was associated with neck flexion, repetitive work, forceful exertion or extreme work postures involving the neck-shoulder muscles on one hand, and an insufficient evidence for the association with hand-arm vibration on the other hand.
We found an association between computer working and risk of ND which is controversial in the literature.
This study comforts that high job demands, low social support, and low skill discretion, and low job satisfaction increase the prevalence of ND.
CONCLUSION:
ND was associated with a variety of personal and work-related risk factors. In particular, organizational and psychosocial factors had a significant impact independently of biomechanical factors. This is consistent with the biopsychosocial models of aetiology of work-related musculoskeletal disorders.
Table 1: Prevalence of ND during the previous 12 months and the preceding 7 days in Loire Valley region's workers.
n (%) n (%) n (%)
ND during the previous 12 months 725 33.9 747 48.9 1472 40.2
- < 24 hours 186 8.6 147 9.6 333 9.0
- 1 to 7 days 290 13.5 256 16.7 546 14.8
- 8 to 30 days 97 4.5 143 9.3 240 6.5
- > 30 days 83 3.9 111 7.3 194 5.2
- Daily 59 2.7 74 4.8 133 3.6
ND during the preceding 7 days 308 14.3 387 25.0 695 18.8
Risk factors N n OR CI 95%
Age (years) < 30 794 126 1
30-34 559 85 0.97 0.71-1.31
35-39 456 81 1.18 0.86-1.61
40-44 513 94 1.16 0.86-1.57
45-49 482 110 1.47 1.09-1.98
50-54 426 94 1.42 1.03-1.94
≥ 55 197 54 1.93 1.31-2.85
Gender men 2020 289 1
women 1407 355 1.94 1.62-2.33
Previous history of upper limb MSD no 3355 612 1
yes 72 32 1.44 1.17-1.79
Previous history of arthritis no 2775 472 1
yes 652 172 3.30 2.01-5.41
Work pace depending of colleagues' work no 2355 410 1
yes 1072 234 1.25 1.03-1.51
Work pace depending on customers' demands no 1906 324 1
yes 1521 320 1.31 1.09-1.57
Sustained and repeated neck flexion no 2552 421 1
yes 875 223 1.41 1.16-1.72
Work with arms abducted (60 to 90°) >2h/day no 2900 517 1
yes 527 127 1.46 1.16-1.85
High psychological demand no 1724 274 1
yes 1703 370 1.27 1.05-1.52
Low social support from supervisor no 2075 342 1
yes 1352 302 1.42 1.18-1.70
Table 2: Risk factors for ND during the preceding 7 days in Loire Valley region's workers.
N : total workforce ; n : number of ND during the preceding 7 days.; OR : Odd's Ratio ; CI95% : 95% Confidence Interval
Men Women Whole
% of prevalences
The Burden and Determinants of Neck Pain in Workers. P. Cote et col. Spine 2008. Work relatedness of chronic neck pain with physical findings-a systematic review. K.T. Palmer et col Scan J Work Environ Health 2007. Risk factors for the onset of non-specific neck pain: a systematic review. S.M McLean et col. J Epidemiol Community Health 2010. Risk factor for neck and upper limb disorders: results from 24 yeras of follow up. K. Fredriksson et col. Occup Environ Med 1999.
