Cognitive load assessment of active back-support exoskeletons in construction: A case study on construction framing

Active back-support exoskeleton has emerged as a potential solution for mitigating work-related musculoskeletal disorders within the construction industry. Nevertheless, research has unveiled unintended consequences associated with its usage, most notably increased cognitive load. Elevated cognitive load has been shown to deplete working memory, potentially impeding task performance and situational awareness. Despite the susceptibility of exoskeleton users to increased cognitive load, there has been limited empirical evaluation of this risk while performing construction tasks. This study evaluates the cognitive load associated with using an active backsupport exoskeleton while performing construction tasks. An experiment was conducted to capture brain activity using an Electroencephalogram, both with and without the use of an active back-support exoskeleton. A construction framing task involving six subtasks was considered as a case study. The participants' cognitive load was assessed for the tested conditions and subtasks through the alpha band of the Electroencephalogram signals. The study identified the most sensitive Electroencephalogram channels for evaluating cognitive load when using exoskeletons. Statistical tests, including a one-way repeated measure ANOVA, paired t-test, and Spearman Rank were conducted to make inferences about the collected data. The results revealed that using an active backsupport exoskeleton while performing the carpentry framing task increased the cognitive load of the participants, as indicated by four out of five significant Electroencephalogram channels. Selected channels in the frontal and occipital lobes emerged as the most influential channels in assessing cognitive load. Additionally, the study explores the relationships among Electroencephalogram channels, revealing strong correlations between selected channels in the frontal lobe and between channels in the occipital and frontal lobes. These findings enhance understanding of how specific brain regions respond to the use of active back support exoskeletons during construction tasks. By identifying which brain regions are most affected, this study contributes to optimizing exoskeleton designs to better manage cognitive load, potentially improving both the ergonomic effectiveness and safety of these devices in construction environments.