The Penn State Safety Floor: Part I--Design parameters associated with walking deflections

• Published in: Journal of biomechanical engineering Vol. 120; no. 4; p. 518
• Main Authors: Casalena, J A, Ovaert, T C, Cavanagh, P R, Streit, D A
• Format: Journal Article
• Language: English
• Published: United States 01-08-1998
• Subjects: Accidental Falls; Compressive Strength; Elasticity; Equipment Design; Ergonomics - methods; Finite Element Analysis; Floors and Floorcoverings - methods; Hardness Tests; Humans; Nonlinear Dynamics; Polyurethanes - chemistry; Predictive Value of Tests; Reproducibility of Results; Safety Management - methods; Walking; Weight-Bearing
• ISSN: 0148-0731
• DOI: 10.1115/1.2798022

A new flooring system has been developed to reduce peak impact forces to the hips when humans fall. The new safety floor is designed to remain relatively rigid under normal walking conditions, but to deform elastically when impacted during a fall. Design objectives included minimizing peak force experienced by the femur during a fall-induced impact, while maintaining a maximum of 2 mm of floor deflection during walking. Finite Element Models (FEMs) were developed to capture the complex dynamics of impact response between two deformable bodies. Validation of the finite element models included analytical calculations of theoretical buckling column response, experimental quasi-static loading of full-scale flooring prototypes, and flooring response during walking trials. Finite Element Method results compared well with theoretical and experimental data. Both finite element and experimental data suggest that the proposed safety floor can effectively meet the design goal of 2 mm maximum deflection during walking, while effectively reducing impact forces during a fall.