Regional variation in digital cushion pressure in the forefeet of horses and elephants

Horses and elephants have extreme foot designs; horses have an unguligrade foot posture with small, single-toed, rigid hooves housing a small fibrous digital cushion, whereas elephants have large, multi-toed, functionally plantigrade, compliant feet with large adipose filled digital cushions. The morphology of the digital cushion is divergent in these species, in terms of its size, shape, volume, composition and organisation. In the context of foot-ground contact this is interesting, because feet nonetheless have to perform similar mechanical functions in all terrestrial species. How well the digital cushion functions under load may contribute to the aetiopathogenesis of foot disease; a sub-optimal digital cushion is less likely to distribute (and thus reduce) high pressures, moderate impact shock and vibration, or prevent unwarranted bone displacement.