# Skilled Workers' Perspectives on Utilizing a Passive Shoulder Exoskeleton in Construction
## 4 Discussion  
The uptake of exoskeleton use within the construction industry has been lagging, despite several studies demonstrating their benefits and positive user acceptance under simulated construction-related tasks. To facilitate adoption, our field study built upon the existing literature and bridged key knowledge gaps [20] by exploring end-users' perspectives of exoskeletons to better understand their applicability, use cases, and whether the benefits observed in the simulations translated into the non-cyclical and complex nature of construction work. Multiple simulation studies have assessed the Paexo Shoulder (Ottobock, Duderstadt, Germany), which is a similar exoskeleton to the one used in our study. A review of the user manuals for both exoskeletons showed similar, if not identical, technical specifications, features, and user instructions. In-lab evaluations of the Paexo Shoulder showed significant reductions in metabolic costs, whole-body joint effort, and shoulder muscle activity during simulated overhead drilling tasks without increasing low back strain, degrading balance, or compromising task performance [27; 28; 29; 30]. Further, study participants did not express fear or concern about wearing the exoskeleton and stated they would want to use it again for a similar task [30]. Reductions in shoulder muscle activity were also found among aircraft workers when performing simulated horizontal vrieting tasks when using the Paexo Shoulder [31]. Consistent with the findings above, over 80% of the construction workers in our study found the EXO-01 to be beneficial for reducing their efforts in overhead work. Our participants also liked how the exoskeleton was lightweight and easy to use. The majority also felt safer while wearing an exoskeleton for overhead work and liked how they looked with it on. In addition to overhead drilling, our participants found that the exoskeleton was applicable to tasks that involved lifting, positioning materials, and operating tools, such as installing electrical conduits, mudding and taping, or hand-tightening light fixtures. However, the adoption rate within our study sample was lower than the one reported in the simulated laboratory study, 66% vs. 100%, respectively [30]. Such contrasts may not be surprising given the different study samples (construction workers vs. students) and conditions under which the exoskeleton was placed (8 h construction work vs. 12 min simulated overhead drilling). Yet, the adoption rates from a six-week naturalistic study were comparable [14]. For example, the researchers implemented a different exoskeleton, the Skelex 360 (Skelex, Den Haag, The Netherlands), among drywall finishers and plasterers, and after six weeks, 65% of the workers reported that they would use it in the future for specific tasks. Application of the exoskeleton for actual tasks in the workplace revealed certain conditions that workers found challenging and identified specific design features construction workers found necessary for their work:  
1. **Compatibility with other tools and PPE. ** Participants felt encumbered when wearing the exoskeleton over their toolbels, harnesses, and sometimes jackets. The exoskeleton should be compatible with toolbels and harnesses to avoid overlapping of straps and belts around the waist area or covering the D-ring of the safety harness. 2. **Sufficient mobility to access tools on toolbelt. ** Almost three-quarters of the participants mentioned that the EXO-01 reduced their maneuverability. Workers mentioned that reaching for the back of the thigh was restricted, an essential movement for accessing tools on the toolbelt. Although [PERSON] et al. (2020) did not find any mobility restrictions in their study, this range of movement may not have been examined in the simulated tasks [30]. It is to be expected that wearing an exoskeleton would reduce maneuverability. [PERSON] et al.