Impact of Anthropometric Secular Trends (1980–2025) on the Dimensional and Structural Requirements of Wooden Beds

Abstract

Long-term anthropometric changes (1980 to 2025) of young adults (aged 18 to 25) were evaluated in the Czech Republic and Slovakia to inform the design of wooden beds. Both populations exhibited identical anthropometric parameters and secular trends: mean body mass increased by 6.2 kg (~1.4 kg/decade) in men and 7.1 kg (~1.6 kg/decade) in women. To address these changes, updated single-bed dimensions are proposed, extending the bed length from 200 cm to a minimum of 220 cm (recommended: 240 cm) and increasing the width from 90 cm to a minimum of 100 cm (recommended: 141 cm). A 3D finite-element (FE) model evaluated structural performance under a design load of 250 kg, which surpasses the reference single-user body mass (~110 kg) specified in EN 1725:2023. The analysis identified the side rails as the most critical structural components. Stiffness was verified against the Eurocode 5 (EN 1995-1-1) L/300 criterion (an 8.0 mm limit for a 2400 mm span). Maximum vertical deflections (6.2 mm for oak and 8.2 mm for spruce) and lateral deflections (5.2 mm and 6.8 mm, respectively) demonstrated that oak satisfies the stiffness requirements, whereas spruce marginally exceeds the allowable deformation limit. The findings confirm that current furniture design standards fail to align with the anthropometric realities and require updates.