Accuracy of spine cumulative loading using self-reported duration and frequency information during non-occupational tasks

Abstract

Cumulative spinal loads have been shown to be independent risk factors for LBP reporting in industry. However, collection and analysis of this type of data is expensive and time-consuming, particularly if non-repetitive tasks, such as those that are common in non-occupational activities in the home, are assessed. Cumulative load assessment costs may be reduced if self-report methods could be utilized, in lieu of traditional video-based approaches. The purpose of the present study was to investigate the accuracy of two types of self-report methods for estimating cumulative low back loads using frequency and duration information gathered during simulated non-occupational tasks. Eight male and 8 female subjects participated in this study in one of two reporting conditions (LOG: reporting done after each task; RECALL: reporting done after end of 2 h session). Mean relative errors between cumulative loads determined from subject reports of frequency and duration and from direct exposure measures from video were under 10% in general and were greater for the RECALL than the LOG condition for all cumulative loads. The difference in relative error between conditions was only significant for cumulative flexion/extension moment. Estimated and actual cumulative moments were highly correlated in the LOG condition ( r = 0.989 , p < 0.001 ), and only moderately so in the RECALL condition ( r = 0.403 , p < 0.001 ). The LOG approach showed promise as an inexpensive and accurate method for documenting frequency and duration information for the estimation of cumulative low back loads. Relevance to industry Cost effective documentation of cumulative loads in non-occupational tasks may help to explain why low back pain continues to persist in occupational settings despite the modification of peak work exposures that regularly occur in industry. Self-report methods may provide a less time and equipment intensive approach for documenting cumulative exposure and be useful for assessments of industrial tasks with varied time demands that pose significant challenges using traditional video-based approaches.