When did I last pay attention to my feet? It's the London Marathon next weekend, so some trotters are receiving a little more TLC. In a marathon, the human foot - with its 26 bones, 33 joints, more than a hundred ligaments, thousands of nerve endings, and vast network of tendons and blood vessels - is sorely tested. During a 26-mile run, a foot will make around 37,000 strikes, each at a force of up to four times the runner's weight. That means that with every mile, a runner or walker will shift approximately 100 tonnes (the weight of a Blue Whale).
Still, somehow we can't take feet seriously. Nearly every condition they suffer - bunions, corns, fallen arches, ingrowing toenails, athlete's foot - sounds like the subject of a well-worn joke. Smelly socks (more conservatively and correctly known as bromihidrosis) are a staple of schoolboy humour. And even if an ailment isn't funny, it's hardly a strictly medical matter.
But, as self-confessed flat-footer Alastair Campbell and other marathon runners know, extremity abuse can be painful. Corns are the thickening of surface layer of the skin caused by pressure; the corn forms in an attempt to protect the skin, like calluses on the hands of manual workers. But as it thickens, it can lead to deformities. Athlete's foot - fungus usually between the toes - causes itching, blisters and cracking skin. Like veruccae, it is usually caught in damp areas around showers and swimming pools where fungus can breed easily, and most often attacks the feet because shoes create a warm, dark and humid environment in which it flourishes.
Sweat and feet go together; there are more sweat glands per square centimetre of our feet than anywhere else on our bodies, and an average pair of hooves will produce half a pint of perspiration per day without any running at all.
Fine sunny weather is a challenge to how we should clad our feet. Slip-ons, mules and flip-flops force us to crunch up our toes just to keep them on, encouraging calluses. Strappy stilettos and pointed toes are even worse; they put pressure on the forefoot that can lead to inflamed joints and tenderness on the ball of the foot. Kitten heels are too unstable, threatening a sprained ankle. (Unsurprisingly, women have four times as many foot problems as men.) Nike and Adidas will be pleased to learn that trainers - with their shock-absorbent soles and wide toes - are the best all-round footwear.
The Foot Foundation suggests determining your correct size by standing on a piece of thin card and marking the place reached by the longest toe. Then cut out the shape and insert into the footwear; there should be a one-centimetre gap between the end of the cardboard and the shoe's heel. When they're fitted is also important; the Foot Health Foundation (feet aren't short of professional bodies) recommends shoe shopping in the mid-afternoon, when the feet are slightly swollen. There may also be a seasonal element; curiously, children's feet often grow faster in spring and summer, and hardly at all in winter.
We cannot confess to loving our feet - or anyone else's, for that matter. To do so would be admitting that we are fetishists; feet are considered so outside the realm of regular sexual activity that it's a cliche that Englishmen have sex with nothing but their socks on.
But I have tried to be at least kind to my feet, given the amount of work they do. I have calculated that, if I live to an average age, my size sixes will have taken me around the world four times. Then, when I am dead, the label to identify my body will be hung on my big toe, as if it were designed for that purpose. It is strange, but it seems to be feet that protrude from body bags, the bare soles letting us know that they contain a corpse. I know someone who, when they saw their dead boyfriend's feet, so quickly and unexpectedly taken from her, kissed them.