Abstract: Compression leggings act as external bio-functional supports that enhance postural stability and gait performance. This study developed a subject-specific three-dimensional Finite Element (FE) model of the female lower body to investigate the biomechanical interactions between compression leggings and underlying tissues, focusing on interface pressure, soft tissue deformation, and intramuscular stress. A distinctive and comprehensive methodology reconstructed anatomically accurate geometries from high-resolution Magnetic Resonance Imaging data to segment nine major muscle groups. Region-specific hyperelastic properties were assigned from in vivo indentation tests, and orthotropic fabric properties were characterised through uniaxial tension and shear testing. FE simulations revealed non-uniform responses: interface pressure decreased from the calf to the low hip before increasing at the high hip, with higher anterior pressures linked to anatomical curvature. Tissue deformation peaked at the high hip and was minimal at the calf, while muscle stress reflected tissue stiffness and pressure, with the highest values in the calf anterior. These findings inform biomechanics-oriented design strategies, where gradient compression and fabrics with varied elasticity, anisotropic stretch, or engineered knits are optimised to align with local tissue properties and curvature. Model predictions agreed with experimental measurements (errors: 15.4% in pressure; 16.0% in deformation), supporting digital evaluation and virtual optimisation of compression leggings to enhance functionality, comfort, and realism in both physical and metaverse applications.

Key words: Compression leggings')">Compression leggings, FE model, Biomechanical effects, Interface pressure, Tissue deformation, Tissue stress