Exploring Placebo and Nocebo Effects in Occupational Exoskeleton Use

Background: Occupational exoskeletons (OEX) may reduce musculoskeletal disorder (MSD; including back, neck and shoulder pain) risks. Many workers with MSD believe they are directly caused by physical work, although evidence causally linking occupational load to MSD is limited. Advances in pain research show that several interacting biopsychosocial (BPS) factors contribute to MSD. Ergonomic messaging can reinforce workers’ negative beliefs, potentially leading to nocebo effects. Nocebo and placebo effects have not been studied in OEX use, though likely relevant in this context.<br/>Aim: Examine placebo and nocebo effects in OEX use during work.<br/>Method: A 3-week A-B-A single case experimental design (SCED) study. Workers from healthcare and construction, new to OEX, will be assigned to an experimental (receiving detailed OEX benefits, risks, and uncertainties) or control group (receiving standard instructions). Phases include a baseline week (regular work), an intervention week (OEX use with varied support), and a reversal week (regular work). Surveys will capture user experiences of support, reassurance (fears about pain), discomfort, and usability, followed by an interview exploring acceptance factors. Analyses include repeated measures and mixed ANOVAs, paired t-tests, and descriptive statistics. Expected nocebo effects include lower reassurance and baseline discomfort scores in the experimental group, while placebo effects are expected as higher experienced OEX support, productivity, and acceptability scores.<br/>Discussion: This innovative study is first to explore placebo and nocebo effects in OEX use, utilizing a SCED approach novel in OEX research. Findings will advance understanding of BPS factors in OEX wear, highlighting OEX potential to enhance work sustainability and health in physical work. Preliminary results will be presented during the congress.<br/>