Ergonomic redesign of overhead crane cab seats based on anthropometric data of Iranian operators

Background Overhead crane operators are exposed to a high risk of musculoskeletal disorders (MSDs), partly due to poorly fitted cab seat designs that do not match operator anthropometry. Objective This study examined the mismatch between cab seat dimensions and the anthropometric characteristics of crane operators and proposed an ergonomic redesign to reduce MSD risks. Methods Sixty-four operators were evaluated using the Rapid Upper Limb Assessment (RULA) method during eight key tasks. Anthropometric measurements were compared with existing seat dimensions. A new seat was modelled in 3D MAX software, incorporating operator anthropometry. Results Significant mismatches were identified in seat height, handle height, backrest width, seat depth, and backrest height. The proposed design included a seat height of 41–56 cm, a width of 47 cm, a depth of 53 cm, and a head/neck support height of 108 cm. Simulation showed that the redesigned seat reduced RULA risk scores from 4 (high risk) to 1 (low risk). Conclusion The findings demonstrate the importance of integrating ergonomic and anthropometric principles into cab seat design. The redesigned seat offers improved postural support, reduces MSD risk, and may enhance operator comfort and performance.