Okay, let’s just get this out of the way now. The funny bone? Not the least bit humorous. In fact, one might even call it the Steve Urkel of body parts—painfully annoying and undeserving of even the slightest chuckle. Plus, the name is doubly misleading; not only are funny bones not funny, but they aren’t even bones! (When will the lies end?) But for all the falsehoods associated with them, there’s one universal truth we can count on when it comes to funny bones: when hit in just the right spot, they hurt like nothing else. What causes that numb, tingling pain that’s so unique to them? And if they aren’t really bones, then what are they?
Calling It a Funny Bone? The Nerve!
The origins of the term funny bone are often contested. Some believe it’s because the area in question is connected to the humerus, the long upper-arm bone. (Get it? Humerus … humorous! It’s about as funny as the funny bone.) Others argue it has to do with how strange the pain feels when you hit the “bone.” Either way, the name is inaccurate—what we call a bone is actually the ulnar nerve, which travels from the neck to the pinky and ring fingers. It’s responsible for movement and feeling in those two fingers and helps control wrist actions.
Specifically, this nerve uses grooves in the ulna—one of the two forearm bones—and the humerus to do its business. In these areas, the nerve is protected by muscles and bones. But when it runs across the elbow, it encounters very little in the way of protection. That’s where it enters the cubital tunnel, which lacks cushioning muscle or ligaments and offers only a small section of skin, leaving the nerve vulnerable to outside forces.
So when we accidentally bang our flexed elbows against something and feel a sharp pain immediately, that’s the ulnar nerve crying out in protest. It’s being pressed against the humerus bone, which ends at the elbow joint. The tingling, numb sensation that comes shortly afterward travels the same course as the nerve would if it had not been stopped momentarily by accidentally hitting something. That’s why slamming your elbow against a wall, for example, gives the ring and pinky fingers of that arm a pins-and-needles feeling, too.
