Hand clearances in ergonomic design: A scoping review of types, methods, and measurements

Hand clearances, the space available for hand access and operation, are essential for manual workspace design. However, clearance types lack systematic characterization, unified methods, and standardized criteria for defining adequate space during manual tasks. This scoping review analyzed 26 records published between 1960 and 2026. Ninety-four unique clearances were identified and organized into four categories: Openings, Operational Clearances, Object-Specific Clearances, and PPE Allowances. Four methodological approaches and eight methodological gaps were identified, including reliance on static measurements, inadequate treatment of PPE, small or outdated samples, and limited reporting standards. Widely cited clearance values originate from small, demographically narrow 1960s studies and have propagated with limited re-validation. The review introduces the functional clearance margin as a conceptual proposition describing the additional space beyond hand dimensions required for functional operation rather than fit alone. These findings provide a foundation for developing more representative, dynamic, and standardized approaches to hand clearance design.