When you hit 70 you sleep sounder, you feel more alive than when you were 30. Obviously it's healthier to have women on your mind than on your knees.
What looks like the elephant's front knees are actually its wrists. There's a popular internet factoid which states that the elephant is the only animal which has four knees. But it doesn't; it has two knees at the back, and elbows and wrists at the front, exactly like other quadrupeds. Elephants, horses, dogs and all other quadruped mammals have two knees and two elbows. Almost all mammals have basically the same skeletal structure because we are descended from common ancestors.
What you can see in the middle of a horse's front leg gets called the knee but is actually its wrist – a knee joins the femur (thighbone) and the tibia (shinbone) whereas a wrist joins the radius (forearm) and the carpus (the bit the digits are joined to). The bit between its body and the middle of the leg is the forearm. What we think of as the 'lower leg' is analogous to our third metacarpal - the bone linking our wrist to our middle finger. Horses walk around on the equivalent of their middle fingers.
There's a misconception that birds' knees bend in the wrong direction but it's just the same as with any other animal. Birds' legs look like they're backwards because we're actually looking at their ankles. Birds' knees are right by their bodies and normally covered by feathers, and their ankles are well off the ground. Their knees bend exactly like ours do.
Bees do have knees. They definitely have joints in their legs, and they have femurs and tibia – the bones which the knee joins in humans. They don't have kneecaps, however – so while the joints in bees' legs aren't quite 'knees' as we know them, they are still knees by our reckoning.
In the 18th century, saying something was 'no bigger than a bee's knee' used to mean it was very small. The modern phrase 'the bee's knees' seems just to have been a nonsense phrase. The world's smallest ever advertisement (promoting the Guinness World Records website) was a knee band which was fitted to a bee's knee in November 2000. It was the width of a human hair.
When propositioned recently by a woman to 'come upstairs and make love', I had to explain that it was one or the other.
The hollow behind your knee is called a hough.
The adjective 'geniculate' means 'bent like a knee'.
In 2005, a CAT scan of Tutankhamun's mummy showed that rather than being murdered by his brother, he probably died from an infected knee.
The ‘knee-jerk’ reaction when you’re tapped on the knee with a hammer tests an interaction between the thigh muscle and the spinal cord, and does not involve the brain. As it’s a ‘mono-synaptic response’ (i.e. the impulse only has to jump from one nerve to another, once) there are very few variables in play, which is what makes it such a useful test.
It’s not just a matter of seeing if your leg twitches – it’s the relative strength of the twitch which is significant. Too much jerk might indicate a brain tumour, stroke, liver disease, low calcium, low magnesium, hypothermia, multiple sclerosis, pre-eclampsia, spinal chord lesion or tetanus. Too little might mean botulism, a damaged nervous system, Eaton-Lambert syndrome (weakness of arm and leg muscles), Guillain-Barre syndrome (nerve inflammation), polymyositis (severe muscle inflammation) or syringomyelia (spinal cysts).
In June 1947, Laurel and Hardy did a six-day gig at Butlins in Skegness. Part of the job was to judge the Knobbly Knees competition, in which elderly men with rolled-up trouser-legs were subjected to a series of humiliating tasks. They also joined their wives Ida and Lucille in judging the ‘Holiday Lovelies’ competition.
The knobbles on our knees are all different. It has been suggested that they may be as unique as irises and fingerprints – and research has started into the possibility of implementing an MRI scanner that works at knee-level for airport security systems.