The appendages at the end of our forelimbs tend to attract the evolutionary and clinical limelight, but our feet are as important as our hands for our survival and success as a species. We tend to take them for granted, yet the many millions of modern humans who run either competitively or for recreation, or who play sports such as soccer, tennis, and badminton, or who ride, or dance, or swim, or climb, or who stand and walk as part of their work, all depend on their feet. We submit them to unreasonable loads, and expect them to survive our pounding them on hard pavements. We also add insult...