Changes in functional characteristics of heel fat pad with age

Background: This study aimed to investigate age-related changes in the heel fat pad's microchamber and macrochamber layers, particularly focusing on load-induced alterations. Understanding these changes is crucial for elucidating age-related differences in foot mechanics and their potential implications for mobility and comfort. Methods: Fifty-five healthy individuals were divided into three age groups: young adults (≤29 years), middle-aged adults (30–44 years), and elderly individuals (≥45 years). Ultrasonic imaging was utilized to measure the thickness of the heel fat pad's microchamber and macrochamber layers under varying load conditions. Thickness, percentage changes, and ratios of load-induced thickness changes were calculated to assess age-related differences. Findings: Under no-load conditions, both microchamber and macrochamber layers of the heel fat pad were significantly thicker in middle-aged and elderly individuals than in young adults. When load was applied middle-aged and elderly participants exhibited smaller changes in the macrochamber layer and larger changes in the microchamber layer compared to young adults. Interpretation: Our findings suggest that age influences the structural characteristics and response of the heel fat pad to mechanical loading. Thicker heel fat pad layers in middle-aged and elderly individuals under no-load conditions may reflect age-related changes in fat distribution or composition. Moreover, differences in load-induced thickness changes indicate altered mechanical properties with age, potentially affecting shock absorption and overall foot function. Understanding these age-related variations can help develop interventions aimed at preserving foot health and mobility across the lifespan.