In World War II, thousands were turned down for the Forces because they had flat feet, which was thought to put them at risk of hip, back and knee problems on long marches.
In fact, people with flat feet could be at an advantage. A 12-week study of healthy Army recruits published in the Archives of Family Medicine showed those with the flattest feet suffered the fewest injuries.
“For the general population with slightly lower arches than normal, there are definite anatomical advantages,” says Nick Masucci, consultant podiatrist at Newham University Hospital NHS Trust. “Most people who have flat feet have normal arches - their feet appear flat because the foot rolls in. When walking, the arches might almost touch the ground so you can’t see them.
“This rolling absorbs shock vibrations and protects from injury. Those with high arches don’t absorb shock so well, with impact being propelled up through the knees, hips and back.”
To see if you have flat feet, wet them and stand on a flat, dry surface. A normal footprint has a band connecting the ball of the foot to the heel. Flat feet leave a near complete imprint. - Daily Mail