The application of an industry level participatory ergonomics approach in developing MSD interventions

Participatory ergonomics projects are traditionally applied within one organisation. In this study, a participative approach was applied across the New Zealand meat processing industry, involving multiple organisations and geographical regions. The purpose was to develop interventions to reduce musculoskeletal disorder (MSD) risk. This paper considers the value of an industry level participatory ergonomics approach in achieving this. The main rationale for a participative approach included the need for industry credibility, and to generate MSD interventions that address industry level MSD risk factors. An industry key stakeholder group became the primary vehicle for formal participation. The study resulted in an intervention plan that included the wider work system and industry practices. These interventions were championed across the industry by the key stakeholder group and have extended beyond the life of the study. While this approach helped to meet the study aim, the existence of an industry-supported key stakeholder group and a mandate for the initiative are important prerequisites for success.

An analysis of sprain and strain injury data for the New Zealand meat processing industry from national and industry injury surveillance databases

Data on musculoskeletal disorders (MSD) in meat processing and the tasks in which they occur is limited in the literature. This paper provides a summary of such data from the New Zealand industry. Despite the high incidence of MSD in meat processing in New Zealand, little research has been undertaken to identify and assess high-risk tasks and develop interventions to address them. This paper reports on the initial stages of a 2-year government funded project to address these issues. Findings are presented from the analysis of data from two injury surveillance databases. Accident Compensation Corporation national data claims assisted in defining the industry and indicated factors for further assessment, including consideration of claimants' gender, ethnicity and geographical region. National Injury Database industry data claims helped to identify specific tasks in which MSD are more likely to occur by departments and for the two main animal species processed. These factors have helped shape the assessment of high-risk tasks currently undertaken in the meat processing industry.

The role of contextual factors for musculoskeletal disorders in the New Zealand meat processing industry

Musculoskeletal disorders (MSD) are the leading cause of occupational injury internationally. In New Zealand, the highest incidence of MSD is in meat processing, accounting for over half the injury compensation costs for the sector. MSD in meat processing have proven highly resistant to physical, micro-level interventions, suggesting a new approach is required. This paper reports on part of a 2-year study looking at MSD in the New Zealand meat processing industry. The qualitative study involved interviews with 237 workers, management, union and safety personnel in 28 processing sites. These data were summarised into a list of contextual factors, which, it is postulated, may create conditions under which greater exposure to physical and psychosocial factors can occur in meat processing. Some of the contextual factors are recognised as problematic by the industry, but have not previously been associated with MSD risk. The paper concludes by reflecting on conducting MSD research with a focus on contextual factors and how this may influence MSD prevention. The manuscript provides industry-based data on MSD risk and outlines the approach used in its collection. Identifying contextual factors and understanding their role in creating MSD risk may help improve the acceptance and effectiveness of MSD interventions in industry.

The effect on heart rate and facial skin temperature of wearing respiratory protection at work

Twelve New Zealand workers from a range of occupations were studied to investigate the effect of wearing air-filtering respiratory protection on heart rate (HR) and facial skin temperature (Tlip and Tcheek) whilst working. All variables were measured continuously during simulated and actual work. The former allowed physiological measurements to be undertaken during the physical activities carried out during the work task without respirators and without exposure to hazardous airborne substances. Mean heart rates in subjects moving without respirators ranged from 75 to 94 beats/min and from 77 to 98 beats/min during respirator use at work. Mean skin temperature under the mask (Tlip) increased in 11 of the 12 subjects while using respirators (range 1.2-4.8 degrees C) but Tcheek only increased in four (range 0.6-1.5 degrees C). The use of simulated work tasks in the experiment was a compromise. The heart rate data from the real and simulated work indicated that effort and workload, though not identical, were similar. The increase in skin temperature under the mask may account for the reluctance of individuals to wear respiratory protection at work. This region of the face is very thermosensitive.

Unfocused ergonomics?

Ergonomics is now fairly routinely used in industry. Managers often initiate contact with ergonomists. The paper argues that many ergonomists have abandoned some fundamental ergonomics principles and have unwittingly succumbed to 'sitting complacently in the manager's toolbox'. It is also argued that through its inherent diversity, ergonomics is in danger of becoming fragmented and losing its identity.

Predicting heart rate response to various metabolic rates, environments, and clothing

A mathematical model that describes heart rate (HR) responses to different combinations of metabolic levels, climatic conditions, and clothing ensembles was developed. The database that served to construct the model consisted of 48 variations representing a wide range of environmental conditions, clothing ensembles, and metabolic rates. The model, which correlates highly with the observed values (r = 0.88, P < 0.0001), is based on physiological and environmental parameters: HR = 57.1 + 0.6HRi + [0.07M - 19.06 - 0.011(Emax - Ereq)] log t, where HRi is initial HR in beats per minute (at rest before the exposure), t is the time of exposure in minutes, M is the metabolic rate in watts, Ereq is the required sweat evaporation for thermal equilibrium in watts, and Emax is the maximal evaporative capacity of the environment in watts. The model's validity was tested by using two independent databases representing wide ranges of conditions; the correlation between measured and predicted values was found to be highly significant (r = 0.83, P < 0.001 and r = 0.77, P < 0.001, respectively). In summary, the present study suggests a valid predictive model for HR that overcomes some of the difficulties observed in other models.

Heart rate strain indices in Greek steelworkers

The heart rate strain of 14 Greek steelworkers was assessed during the winter and summer months of 1989 and 1990. Activity sampling was used to establish the pattern of work performed and heart rates were measured throughout work shifts. In addition, maximum aerobic capacity was estimated. The mean heart rate during work was 97 bt.min-1 (+/- 13), while the mean relative heart rate increase was 21% (+/- 15%). The results indicated that the work performed could be classified as light to moderate.