Source avec lien : Ergonomics, (En ligne). 10.1080/00140139.2023.2183850
Dans une étude précédente, une relation inattendue en forme de U a été observée entre le niveau de charge et les réactions de fatigue/récupération. Dans cet article, nous avons réexaminé les données publiées précédemment et constaté que le phénomène ne semble pas être dû à l’artefact expérimental ; la forme en U peut être due à des effets de fatigue plus faibles et inattendus à des charges modérées, et à des effets de fatigue plus élevés à des charges plus faibles.
In a previous study, an unexpected u-shaped relationship was observed between load level and fatigue/recovery responses. Moderate load levels resulted in lower perceived discomfort, pain, and fatigue, and shorter recovery times compared to either low or high load levels. This phenomenon has been reported in other studies, but no article has examined the possible mechanisms that might explain this u-shaped relationship. In this paper, we re-examined the previously published data and found that the phenomenon does not appear to be due to the experimental artefact; the u-shape may be due to unexpectedly lower fatigue effects at moderate loads, and higher fatigue effects at lower loads. We then conducted a literature review and identified several possible physiological, perceptual, and biomechanical explanatory mechanisms. No single mechanism explains the entirety of the phenomenon. Further research is needed on the relationship between work exposures, fatigue, and recovery, and the mechanisms related to the u-shaped relationship.Practitioner summary: We examine a previously observed u-shaped relationship between load level and fatigue/recovery, where moderate force resulted in lower perceived fatigue and shorter recovery times. A u-shaped fatigue response suggests that simply minimising load levels might not be an optimal approach to reduce the risk of workplace injuries.