Akademik Veri Yönetim Sistemi
2025 International Mechanical Engineering Congress and Exposition-IMECE, Tennessee, Amerika Birleşik Devletleri, 16 - 20 Kasım 2025, (Tam Metin Bildiri)
This study evaluates the applicability of rigid-body modeling in the human foot during quiet stance using three-dimensional kinematic data. The rigid-body assumption, which posits that anatomical segments such as the calcaneus, navicular, and metatarsals maintain fixed relative positions without deformation, is widely used in biomechanical modeling and orthotic design but has limited empirical validation under static conditions. Ten healthy adults performed a 60-second barefoot quiet stance trial while reflective markers tracked calcaneus, navicular, and metatarsal motion. A rigid, non-biological foot model was recorded under identical conditions to provide a near-zero-variability reference. Three hypotheses were tested: (1) individual foot segments behave as rigid bodies; (2) the foot acts as a unified rigid structure; and (3) the rotational center lies near the metatarsal region. Key kinematic parameters, including inter-segmental distances, navicular height, and internal angles, were analyzed. In some participants (e.g., P01), inter-marker variability ranged from 0.18-0.23 cm, statistically comparable to the rigid model. In contrast, others (e.g., P08) showed variability exceeding 1.0 cm. Variance analysis indicated that the metatarsal segment exhibited the lowest positional variability in five of ten participants, suggesting localized mechanical stability. These findings partially support the rigid-body assumption while highlighting inter-individual variability, underscoring the importance of subject-specific validation in clinical gait analysis, orthotic design, and computational foot models.