The so-called funny bone is actually not a bone. And when you whack it on something, it really is not all that funny. So what is the “funny bone,” and why does it cause so much discomfort when you hit it?

Actually, the funny bone is the ulnar nerve. This is a nerve that extends all the way from your neck to your hand, sending impulses to your hand and your forearm. It terminates at the point where your pinky finger and your ring finger join.

Why the Discomfort?

The ulnar nerve, like all the other nerves in your body, is protected by ligaments, muscles and bones throughout most of its length. However, when it reaches the elbow, it passes through the cubital tunnel. At that point, its only protection is fat and skin, and that makes it highly vulnerable to impact. When you hit it, the nerve comes up against the bone and becomes compressed. That is what causes the tingling, numbness and pain that shoots down your forearm, through your hand and into your fingers.

How Did It Get Its Name?

This is a matter that has been long debated. Some believe that the term is actually a pun, since the nerve runs along the bone known as the humerus, which, of course, sounds just lie “humorous.” Another school of thought is that the name is derived from the “funny” feeling that you get when you hit it. Regardless of the origin, though, our opinion is still that there really isnt anything all that “funny” about a blow to the ulnar nerve.

Could Matters Be Worse?

Yes, actually, they could. Imagine having the sensation of a blow to the funny bone that never goes away. Sometimes it happens, and the condition is known as cubital tunnel syndrome. This occurs when the ulnar nerve becomes obstructed, and then ends up being squeezed or pinched. Often, this is caused by sleeping with your arm folded under you. You get the same feeling as when you hit the funny bone – in other words, tingling, numbness and pain. The trouble is that it lasts longer, and eventually, it may not go away. If the irritation of the nerve is constant, numbness settles in, and the forearm and hand muscles weaken. Then, the ring and pinky fingers can end up curled into a claw-like position.

Treating Cubital Tunnel Syndrome

The most important thing you can do if you have cubital tunnel syndrome is to correct the posture that is causing the pressure on the ulnar nerve. Most often, the pressure is caused when you are sleeping, so putting a pillow under your arm before you go to sleep may offer some relief. If this doesnt help, then your doctor may consider splinting the elbow for a period of time. Hand therapy can also be helpful. In extreme cases, you may need surgery to open up the tunnel so that the nerve has more space, and the pressure on it is reduced.