No, I’m not a foot fetishist, but sportsmen on this side of the Atlantic are very much aware that right now the 4th metatarsal in the human foot is the most illustrious
and written about bone - probably in all our sporting history.
Anyway, I came across this short article which could be of interest to runners everywhere:
At three inches, (7.5cm), metatarsals are the longest bones in the foot, and that makes them vulnerable to stress fractures. Sometimes these are called "march" fractures because they often strike army recruits who have been burdened with 50kg of kit and ordered to pound a parade ground.
Foot-and-ankle specialists have other worries, too, from hammer toes and bunions to strains, sprains and torn ligaments.
Although metatarsals get the most public attention, 40 per cent of disorders involve the big toe. Half the problems, particularly among women, arise from wearing shoes that are too narrow, too high or both.
The human foot is an oddity in nature. No other creature has anything that works quite like it -it's an utterly unique way of walking around.
Even other bipeds have quite different styles of moving. Birds hop and Tyrannosaurus rex kept its body horizontal, but our bodies are upright.
The secret is the foot's unusual evolutionary path. Until 3.7 million years ago, our ancestors lived in trees, their hands and feet adapted to grasp branches.
As they descended to live on the ground, their big toes became fixed for stability, their ankles became more robust to take the full weight of the body, their metatarsals arched to form a spring, and a locking mechanism evolved that turns the whole structure into a powerful lever.
The first evidence of us walking upright comes from fossil footprints in Laetoli, Tanzania, discovered by Mary Leaky. They show two of our Australopithecus afarensis ancestors walking across a plain of volcanic ash in much the same way that we walk today. Their skulls, however, would still have been tiny.
Why we began to stand erect is a matter of debate. Many think it helped our ancestors find food and stay cool as the jungles were slowly replaced by grassland.
But the fossil record is clear about one thing: walking on two legs is the first thing that happens to us as we become human.
When we stand still, the foot has a simple job. It distributes weight through a stable tripod of contact points - the heel and the balls of the toes.
But when we're moving, in what's called the gait cycle, it has more to do. Each stride begins with the heel strike, cushioned by a thick layer of fat. As the body's centre of mass moves forward, the weight shifts to the side of the foot and the knobby end of the fifth metatarsal.
The foot then rolls inwards, which transfers the weight to the first metatarsal and locks the bones into place.
At the same time, three muscles attached above and below the knee pull the Achilles tendon, raising the heel and preparing the foot to push off again from the toes.
Because bones are associated with death, we tend to think of them as solid and inanimate.
In fact, within the smooth outer surface, they're mostly sponge-like and riddled with cells.
Some are constantly breaking down old bone structure, others building new hard bits.
It's these cells that repair fractures. Adult bones can become stronger, too.
X-rays of professional tennis players show that the bones in their racquet arms are thicker.
An orthopedic physician interviewed, says most of the foot injuries he treats are among runners training for the marathon who increase their mileage too quickly: "They're ready in cardiovascular terms, but their bones haven't adapted."