Effect of Long-Term Non-Weight Bearing on the Morphology and Function of the Heel Fat Pad.

BACKGROUND: We aimed to investigate the effects of long-term non-weight-bearing conditions, including prolonged bedridden states, on the morphology and function of the heel fat pad. METHODS: We recruited 13 elderly individuals bedridden for over 1 year (BR group) and 89 age-matched healthy controls (CON group) living independently. Using diagnostic ultrasound imaging, we measured the thickness of the microchamber, macrochamber, and whole layers of the heel fat pad under non-compressed and compressed conditions. RESULTS: Significant reductions in both non-compressed and compressed thicknesses were observed across all layers in the BR group. Furthermore, a significant negative correlation was observed between age and thickness change in the BR group, whereas no such correlation was observed in the CON group. CONCLUSION: Long-term non-weight-bearing was associated with morphological changes and functional deterioration in the heel fat pad. These findings suggest that prolonged unloading may influence heel fat pad morphology, which may be relevant when considering weight-bearing management.