Margin of manoeuvre indicators in the workplace during the rehabilitation process: a qualitative analysis.

INTRODUCTION: The task of evaluating workers' capacity to return to their pre-injury employment or other jobs continues to pose a daily challenge for clinicians. In this study, a concept frequently used in the field of ergonomics, the margin of manoeuvre (MM), was applied during the rehabilitation process. The study identified the indicators of the MM taken into account during the return to work of workers with musculoskeletal disorders. METHODS: This study used a multiple-case design. A case was defined as a dyad comprising a worker admitted to a work rehabilitation program and the clinician who was managing the return-to-work process. The results were then validated with investigators and expert ergonomists, through group interviews. Content analyses were performed using the conceptual framework for the work activity model adapted from Vézina and the procedures recommended by Miles and Huberman. RESULTS: A total of 11 workers, five clinicians, two experts and two investigators participated in this study. The interview analysis process resulted in a more detailed definition of the MM and the identification of 50 indicators. The indicators were classified according to six dimensions: (1) work context; (2) employer's requirements and expectations; (3) means and tools; (4) worker's personal parameters; (5) work activity; and (6) impacts of the work situation. CONCLUSIONS: The more specific indicators identified in this study will allow for more systematic observation of the MM. Subsequent studies will seek to link each indicator described in the model with a specific method of observation.

Workplace interventions for workers with musculoskeletal disabilities: a descriptive review of content.

BACKGROUND: Despite the convergence of scientific data to the effect that interventions in the workplace promote a healthy return to work, the interventions carried out in the real work environment appear to be very heterogeneous and ill-defined. OBJECTIVE: The goal of this review is to identify the different objectives pursued through the workplace interventions carried out in the context of a rehabilitation program, and to describe the activities involved. METHODS: A descriptive review of the literature, including various research designs, was carried out. RESULTS: This review reveals great heterogeneity in the content of interventions offered in the workplace to workers with musculoskeletal disabilities. The objectives of workplace interventions may range from gathering information in order to reproduce work demands in a clinical setting, to gradually exposing workers to the demands of the real work environment, or permanently reducing the demands of the work situation. A descriptive analysis of the literature also brings to light the diversity of actions carried out, human resources used, and workplace environments involved, while highlighting the few documented process outcome evaluations that have been done of workplace interventions. CONCLUSION: It is recommended that in future research in this area, efforts be made to better describe the components of the interventions, to develop process outcomes representing the multidimensional results obtained in the workplace, and to differentiate between temporary and permanent modifications made to the work situation.

When is light work heavy? Components of the physical workload of sewing machine operators working at piecework rates.

Epidemiologists have associated the job of sewing machine operators with a high incidence of musculoskeletal and other health problems, despite its classifications as light work according to energy expenditure criteria. An ergonomic analysis was undertaken in a trouser factory in order to describe components of the physical load of this work: force exerted, repetitions, time allocation and postures. Work activity of ten operators was observed and timed in situ, and forces were measured with a dynamometer. The time required to sew one seam is very short, 10-15 s per trouser leg. This short cycle is repeated more than 1500 times during the work day, involving quasi-continuous movements of the same parts of the body. The fact that movements are repeated so many times means that small details of the task assume a great importance. During the work day, a substantial force is exerted, only part of which can be measured with current technology. By these measurements, operators lift an average 406.1 kg of trousers per day and exert an average total force of 2858.4 kg with the upper limbs and 24 267.9 kg with the lower limbs. The work posture is static: seated with upper back curved and head bent over the sewing machine. Movements of the upper limbs involve abduction and adduction of the shoulders while exerting a force. For the same task, there is considerable variation in the dimensions of workstations. Interviews were conducted to determine the types of musculoskeletal complaints. The components of work activity could be treated to these complaints and to existing epidemiological data on musculoskeletal problems among sewing machine operators. This type of detailed examination can be applied by health and safety personnel to identify task components which could be changed to minimize the probability of musculoskeletal problems.

Integration of women into traditionally masculine jobs.

Jobs are often allocated according to sex, although this distribution is not always justified by biological differences between men and women. Ergonomic analysis of sex-typed jobs in a clothing factory and in a plastics factory revealed that the total weight lifted in women's jobs exceeded that in a typical male laborer's job. The characteristics of work organization and work rhythm also differed according to the sex to whom jobs were assigned: Muscular exertion was intense but sporadic with the men's jobs, moderate but continuous with the women's. Scientific study has not related characteristics of sex-typed jobs to differences between the sexes in average size and shape. However, analysis of two cases showed that average-sized women entering traditional men's jobs may be disadvantaged, if no thought is given to adjusting tools, equipment and work stations. Trying to do a job designed for larger, heavier people may cause health and safety problems. Any improvement in the conditions of these jobs to take into account a wider range of physical characteristics will benefit men as well as women.

The weaker sex? Men in women's working conditions report similar health symptoms.

Recent studies have shown that women factory workers report more health symptoms than men. Reporting of health symptoms by 661 workers at nine poultry slaughterhouses in Québec was examined to determine whether this difference has its origins in sex-specific working conditions. More women than men report that their jobs involve standing still, repetitive movements, and a very rapid work rate. While women workers reported more health symptoms, these symptoms primarily affected the musculoskeletal and nervous systems, and were related to ergonomic and organizational job characteristics. Reported symptom levels were in closer agreement for subsamples of women and men with similar working conditions. This study demonstrates the importance of considering environmental, organizational, and ergonomic conditions at the work station as constituents of a microenvironment in order to understand the complex determinants of health symptoms associated with work in female employment ghettos.

Dysmenorrhea and cold exposure.

As part of a health study undertaken at the request of the employees of eight Quebec poultry slaughterhouses, 213 women workers and 105 housewives responded to a self-administered questionnaire on menstruation. The prevalence of dysmenorrhea among the workers was determined for the last menstrual period and compared with that in the reference group, consisting of full-time housewives married to male slaughterhouse workers. The women slaughterhouse workers had a significantly higher prevalence of dysmenorrhea (73.2%) than the housewives (52.5%) (alpha less than 0.001). This difference was analyzed with respect to factors reported to be related to dysmenorrhea--age, parity, oral contraceptive use and menstrual regularity. Forty-four slaughterhouse workers took sick leave during their last menstrual cycle. The relationship between the prevalence of dysmenorrhea, sick leave and cold exposure at the workplace was examined. Among the workers the prevalence of dysmenorrhea and sick leave increased with increasing cold exposure (alpha less than 0.05 and less than 0.02, respectively). An analysis of the relationship of dysmenorrhea to cold exposure with respect to age, parity, oral contraceptive use and menstrual regularity revealed that factors usually associated with a lower frequency of dysmenorrhea do not apply to women working in a cold environment. These findings indicate that cold exposure influences the menstrual process.

Warts among workers in poultry slaughterhouses.

The objective of the study was to identify the prevalence of warts in poultry slaughterhouses. A questionnaire was administered to 1,194 workers, of whom 569 completed it. The prevalence of warts (Papilloma virus) was found to be 28.5% in slaughterhouses. In the general population it is 7-10%, reaching a peak in individuals around the age of 14 a. In the poultry slaughterhouses, the prevalence was highest (38.7%) in the age category 25-29 a, and among those who had been working 4 to 6 a (40.8%). The factors present in the work environment showed a significant correlation (alpha less than 0.05) with the presence of warts were the following: steel-mesh gloves that were too large for the wearer, work with a saw, handling of cold objects, and high humidity levels. It was concluded that mild abrasion of the skin (too-large gloves) and high humidity facilitate cutaneous infection by the virus, whereas the handling of cold objects and work with a saw provoke local vasoconstriction which could hinder the immune reaction.