Technical field-evaluation of exoskeleton-assisted overhead work among carpenters.

Carpenters in construction commonly perform overhead work tasks such as installing ceiling panels, plastering, and formwork. While laboratory studies suggest exoskeletons may reduce strain during such work, their effectiveness in real-life conditions remains uncertain. This randomized cross-over field study investigates the effects of a passive shoulder exoskeleton on muscle activity and kinematics in 20 carpenters during overhead work tasks. Results showed reduced peak muscle activity (nEMG) in the shoulders and forearms (-3.1 to -9.4 %), but increased activity in the lower back (2.3-3.4 %) when using the exoskeleton. Kinematic analysis revealed minimal changes in range-of-motion (<3.1°) and peak joint angles. Participants reported good usability and willingness to use the exoskeleton in the future. This study demonstrates positive effects on shoulder load in real working conditions but highlights the need to consider increased low-back load when implementing exoskeletons for overhead work.