Comparison of Ergonomic Risk Assessment Output in Four Sawmill Jobs

Abstract

The objectives of this study were to examine the agreement between 5 ergonomic risk assessment methods calculated on the basis of quantitative exposure measures and to examine the ability of the methods to correctly classify 4 at risk jobs. Surface electromyography and electrogoniometry were used to record the physical exposures of 87 sawmill workers performing 4 repetitive jobs. Five ergonomic risk assessment tools (rapid upper limb assessment [RULA], rapid entire body assessment [REBA], American conference of governmental industrial hygienist's threshold limit value for mono-task hand work [ACGIH TLV], strain index [SI], and concise exposure index [OCRA]) were calculated. Dichotomization of risk to no risk and at risk resulted in high agreement between methods. Percentage of perfect agreement between methods when 3 levels of risk were considered was moderate and varied by job. Of the methods examined, the RULA and SI were best (correct classification rates of 99 and 97% respectively). The quantitative ACGIH-TLV for mono-task hand work and Borg scale were worst (misclassification rates of 86 and 28% respectively).

Measurement Consistency Among Observational Job Analysis Methods During an Intervention Study

“…The difference in the results might be related to the way the risk factors, e.g., task length and task pace, were taken into account by the methods but also to the risk factors that were considered. The comparison results added to the results already present in the literature where only RULA was compared to other methods (JSI: Drinkaus, Sesek, Bloswick, et al [20], QEC: Brown and Li [21], OWAS and REBA: Kee and Karwowski [22], REBA, ACGIH TLV, SI and OCRA: Jones and Kumar [23,24]). With this study we added the comparison between OCRA and QEC.…”

“…There are still few studies that compare the results of different methods and those are mainly qualitative [9,10,11,12,13,14,15,16,17,18]. Only few other studies quantify the differences and similarities [19,20,21,22,23,24]. Some of these studies cover only exposure to the low back [16,17,18,19].…”

“…Some of these studies cover only exposure to the low back [16,17,18,19]. However, the only comparisons between observational methods that address exposure to multiples body segments are between RULA and JSI [20], QEC and RULA [21], OWAS, RULA and REBA [22] and RULA, REBA, ACGIH TLV, SI and OCRA [23,24]. A gap exists especially for comparisons of observational methods other than RULA.…”

Biomechanical Loads and Subjective Stress Exposure to Lumber Graders in Sawmill Industry

“…This represented 33% of the total cost of claims and 38% of the total time lost due to claim in the same period. Within the sawmill industry the lumber grader position was identified as a production position with a high risk of musculoskeletal injury (MSI) to the upper extremity [1,2]. Incidence of recordable upper extremity MSI events in the lumber grader position ranged from 1.09 to 1.25 per person-year worked in this occupation.…”

“…A large evidence base establishing the role of exposures to postural and biomechanical loads in precipitation of MSIs is now present and a number of probable mechanisms of injury have been proposed [2,3]. In most musculoskeletal conditions, it is the combined effect of physical exposures which are most highly related to the incidence of MSI [2]. Ergonomic risk assessments are based on models of MSI causation which consider the integrated role of biomechanical and physiological exposures.…”