Steele F. Stewart. “Footgear – Its History, Uses and Abuses,” Clinical Orthopaedics and Related Research, 88, 1972, pp. 119-130.

Excerpts:

All writers who have reported their observations of barefooted people agree that the untrammeled feet of natural men are free from the disabilities commonly noted among shod people — hallax vagus, bunions, hammer toes, and painful feet. …

Millions of Indians, both American and Asian, and Congoids wander their native savannas and rain forests without protection, inconvenience, or complaint. Footgear, therefore, would appear to be unnecessary. …

We should learn from primitives the pleasure and painlessness of going barefoot …