Are Worker Perceptions of Task Ease and Performance Associated with Within-subject Motor Variation during Repetitive Work?

Abstract

A feature of repetitive motion believed important to understanding work-related musculoskeletal disorder risk is the absence of posture variation between task cycles. Motor control studies suggest that (i) individuals with greater task performance demonstrate more consistent motion patterns (i.e., reduced posture variation) and (ii) there exists an association between actual and self-reported per- ceptions of task performance during repetitive physical activity. The objective of this analysis was to compare the within-subject between-cycle variation of postural and muscle activity metrics during a repetitive welding task between individuals with perceptions of low and high task ease and performance. Although the majority of the relationships do not appear to be statistically significant, participants with perceptions of high task ease and performance demonstrated different magnitudes of cycle-to-cycle variation across multiple postural and muscle activity metrics. We recommend a future research agenda to further investigate the effects of worker perceptions on within-subject motor variation during repetitive work.