Is there anything quite as un-funny as hitting your funny bone? Not only does it hurt, it hurts in the strangest way – a truly unique sort of torture. But why?
Contrary to what its name suggests, the funny bone is not actually a bone at all. Instead, it’s a nerve; specifically, the ulnar nerve. The ulnar nerve travels down from the neck along the arm to the hand. It’s responsible for communication with several of the muscles in your hand and forearm, as well as your pinky and part of your ring finger.
Almost all the nerves in your body are shielded by various structures including bone and muscle. Most of the ulnar nerve is no exception – until you get to the cubital tunnel. This area, right at the elbow, is exposed and vulnerable, with only some skin and fatty tissue in between it and the outside world. Anytime you bump your funny bone, the nerve is pressed and compressed against the bone in your elbow, which causes an array of unpleasant sensations. You’ll feel the tingling and pain all the way down the nerve, from your forearm to your fingers.
So if it’s not a bone, why do we call it a bone? Why isn’t it called the “funny nerve”? Some people claim that the name comes from a pun on the humerus, which runs alongside the ulnar nerve; “humerus” becomes “humorous”. Other people say the name comes from the actual sensation, which is a “funny” sensation in the sense that it’s unique and rather strange.
Whatever its origin, there’s no denying that hitting your funny bone is among the worst sensations in the world. But you could have it a lot worse: some people suffer from what’s known as cubital tunnel syndrome; this condition makes it seem like you are constantly hitting your funny bone, every minute of every day.
Cubital tunnel syndrome is the result of an obstruction in the path of the ulnar nerve which will either pinch or squeeze the nerve near the elbow. It’s a common side effect of sleeping with your arm in a weird position, and it causes the same sensations as hitting your funny bone, but for an extended period of time. If the condition continues, it could become more permanent, leading to a constant numbing sensation as well as muscle weakness and a condition known as “ulnar claw”, where your pinky and ring finger curl up and stiffen. Cubital tunnel syndrome usually calls for an elbow splint as well as physical therapy to prevent the sufferer from continuing their bad habits. Extreme cases may require surgery. So next time you think your life is over because you whacked your funny bone, think about how much worse it could be.