Ergonomic design and evaluation of masons' trowels for construction work

This study investigated the effects of five redesigned masons' trowels (with handles with variable cross-section that provided different patterns of grip) and hand anthropometry on muscle activity, usability and affordance in a working context, and the results were compared with that of the traditional design with longitudinal round cross-sectional handle. The results showed some improvements in terms of usability and affordance with the second prototype design. Usability was also improved with the first prototype trowel design, although it required higher electromyographic activity levels compared to some other designs. Hand anthropometric measures had no effect on the studied measures. The results suggest that although improving performance and usability may not necessarily be compatible objectives, the idea of cylindrical tool handles with variable cross-section can be employed advantageously to improve the tool's usability. The findings may also rule out the possibility that users' hand anthropometry is always necessary for the design of tool handle. Rather, hand tool designers and manufacturers should pay special attention to the working context and quality of hand-handle interaction to improve the design and usability of hand tools.