The Truth About Your Funny Bone

You have likely hit your funny bone before and didn't find it funny. It hurts. The term "funny bone" is strange, though, because it isn't a bone at all; it's a nerve. That's why bumping it can be so painful. According to Live Science, the nerve runs from your spine to your neck and down to your hand, and is called the ulnar nerve. The ulnar nerve sends signals back and forth between your fingertips, particularly your ring and pinky fingers, and your brain. That's why if you hit that nerve in your elbow, you can feel the tingling sensation all the way down to your fingers. 

The nerve is protected by muscle, fat, and bone, but loses a tiny bit of that protection in your elbow. So there's a small window of exposure, and sometimes when you hit your elbow just right — or wrong in the case — you feel it. That's when the ulnar nerve gets squished between your bone and whatever you hit it on. Verywell Health describes this pain as a "quick jolt" or "electric shock-like pain." It typically fades in a minute or two, but for some unlucky people, this pain doesn't pass. 

What is ulnar nerve entrapment?

Some people experience chronic pain in their ulnar nerve — according to Johns Hopkins Medicine this is called ulnar nerve entrapment, also known as cubital tunnel syndrome, tardy ulnar palsy, Guyon's canal syndrome, bicycler's neuropathy, or handlebar palsy.

For some people, the ulnar nerve doesn't stay put and instead moves around on the bone when they move their arm. Direct pressure can also cause ulnar nerve entrapment, like when a bicyclist leans on their handlebars for long periods. Another cause can be using tools for a long time. The American Academy of Orthopaedic Surgeons (AAOS) explains that other potential causes include elbow injuries, cysts, swelling, fracture, or bone spurs.

According to the AAOS, symptoms are tingling and numbness in the ring and pinky fingers, weakness, and trouble with coordination in those fingers. Johns Hopkins adds that you might feel sensitive to cold, and your elbow may feel tender. If not treated, muscle in the hand can begin to weaken. If you have these symptoms, see your doctor immediately. They may do a physical examination, X-ray, or nerve conduction test. Treatment includes taking anti-inflammatories, using an elbow brace, and physical therapy. Sometimes surgery is necessary. But luckily, for most of us, the pain of hitting that funny bone only lasts a few minutes at most.