Evolution of osteoarticular disorders as a function of past heavy physical work factors: longitudinal analysis of 627 retired subjects living in the Paris area

Low back pain around retirement age and physical occupational exposure during working life

BACKGROUND

Physical occupational exposure is a risk factor for low back pain in workers but the long term effects of exposure remain unclear. As several countries consider increasing the retirement age, further information on this topic is relevant. This study aimed to describe the prevalence of low back pain among middle aged and aging individuals in the general French population according to physical occupational exposure and retirement status.

METHODS

The study population originated from the French national survey 'Enquête décennale santé 2002'. Low back pain for more than 30 days within the previous twelve months (LBP) was assessed using a French version of the Nordic questionnaire. Occupational exposure was self assessed. Subjects were classified as "exposed" if they were currently or had previously been exposed to handling of heavy loads and/or to tiring postures. The weighted prevalence of LBP was computed separately for men and women, for active (aged 45-59) and retiree (aged 55-74), according to 5-year age group and past/present occupational exposure.

RESULTS

For active men, the prevalence of LBP was significantly higher in those currently or previously exposed (n = 1051) compared with those never exposed (n = 1183), respectively over 20% versus less than 11%. Among retired men, the prevalence of LBP tended towards equivalence with increasing age among those previously exposed (n = 748) and those unexposed (n = 599).Patterns were quite similar for women with a higher prevalence in exposed active women (n = 741) compared to unexposed (n = 1260): around 25% versus 15%. Similarly, differences between previously exposed (n = 430) and unexposed (n = 489) retired women tended to reduce with age.

CONCLUSION

The prevalence of LBP in active workers was associated with occupational exposure. The link with past exposure among retirees decreased with age. These results should be considered for policies dealing with prevention at the workplace and retirement.

Biomechanical strains and low back disorders: quantifying the effects of the number of years of exposure on various types of pain

OBJECTIVE

To assess the effects of duration of exposure to biomechanical strains on various types of low back pain (LBP).

METHODS

The population study was a random sample from the GAZEL cohort. Durations of exposure to selected biomechanical strains during subjects' working lifetime and potential confounders were assessed in 1996 by self-administered questionnaires. Data on LBP in the previous 12 months were collected in 2001. Relations between various dimensions of LBP and durations of exposure to the biomechanical strains were analysed with multivariate regression models. Polytomous models were built to determine whether some biomechanical strains were specifically associated with some types of LBP.

RESULTS

Analyses were performed separately for men (n = 2218) and women (n = 383). Significant associations were observed (ORs reported are those for 20 years of exposure) between LBP and durations of driving and bending/twisting for men (OR 1.24 and 1.37 respectively); LBP for more than 30 days and duration of exposure to bending/twisting for men and women (OR 2.20 and 2.00 respectively) and duration of driving for women (OR 3.15); LBP radiating to the leg and duration of driving for men (OR 1.43) and bending/twisting for women (OR 1.95); LBP radiating below the knee and duration of exposure to pulling/pushing/carrying for men (OR 1.88). Bending/twisting in both men and women, and driving for women appeared to be stronger risk factors for LBP for more than 30 days. Pulling/pushing/carrying heavy loads appeared to be a risk factor specific for LBP radiating below the knee for men.

CONCLUSION

This study suggests that exposure to biomechanical strains has long-term effects and a dose-response relation with duration of exposure and specific effects for some types of LBP.

Relation between locomotion impairment, functional independence in retirement, and occupational strain resulting from work carried out during working life. Study of a sample population of 350 miners in the Loire valley in France

STUDY OBJECTIVES

To analyse long term effects of working conditions experienced at an advanced age, and after retirement by quantifying occupational strain, impairment, and disability to establish their interrelation.

DESIGN

Retrospective study.

PARTICIPANTS

Retired miners from The French Coal Board who had worked in the coal fields of the Loire valley. From a potential population of 507 retired miners, 350 were completely evaluated.

MEASUREMENT

The study examines the occupational strain experienced by each subject, measured using both auto-evaluation and evaluation by experts and the locomotion impairment and the functional independence.

MAIN RESULTS

A significant relation between the evaluation of occupational strain and functional independence and locomotion impairment of the low back was found and also a significant relation between locomotion impairment of the low back and the length of time spent working at the coal face.

CONCLUSIONS

This study confirms other studies as regards the effects of occupation on health status and on the aging process, but it goes further to show the consequences of this relation on functional independence.

Economic impact of ergonomic intervention-Four case studies

The economy of ergonomic improvements is reported as case studies from four Swedish companies. Poor workplace ergonomics and related musculoskeletal problems were already known and had caused repeated sick- leave periods at these workplaces. Expenses associated with certain preventive activities were accounted for and financial effects were estimated based on interviews with representatives at the companies. When costs were compared to gains, the improvements appeared to be highly profitable.

Factors influencing ergonomic conditions and employment rate after an occupational musculoskeletal injury

In 195 cases of musculoskeletal occupational injury individual and work related factors and their relationship with reduction of physical work load and active employment was studied. Data concerning the injuries were obtained and after 18 months the work places were assessed. Information on employment status was obtained by a postal questionnaire after 3 years. Multiple logistic regression was used to explain the two outcome measures. Injuries classified as diseases and informative injury reports were factors positively associated with reduction of work load. Male gender, higher education, and a sick-leave shorter than 6 months were factors positively associated with employment.