The foot pads of many mammals provide cushioning using hydrostatic structures, essentially working as fluid-filled cushions.

References

"Human heel pads and other mammalian foot pads make use of hydroskeletal support; our pads, which provide impact damping, some energy storage, and protection for bones, work as fluid-filled cushions--see, for instance, Ker (1999). They're complexly viscoelastic--if you want a stable reading of your height, you should stand for almost two minutes to allow your pads to creep into stability (Foreman and Linge 1989)." (Vogel 2003:417)

Book
Comparative Biomechanics: Life's Physical World, Second EditionJune 17, 2013
Steven Vogel

Journal article
The design of soft collagenous load-bearing tissuesThe Journal of Experimental BiologyDecember 1, 1999
Ker RF

Living System/s

Organism
MammalsMammaliaClass