As you reach backward to pull your chair and sit up straight, your elbow smashes into the chair’s arm, hitting directly on the “sweet spot”. Waves of pain, what people often describe as an “electric shock”, promptly ripple through your arm, from the mighty elbow to your little pinkie. But what’s so special about this spot? Why does banging it hurt so awfully?
The spot is called the funny bone, although it’s anything except a bone, and certainly doesn’t make you laugh. The jury is still out on whether the spot is called “funny” due to the eerie sensation that hitting it invokes, or if it is merely wordplay on humerus, the name of the bone below which this area is situated.
The funny “bone” is actually a long vine of a nerve called the ulnar nerve that emanates from your neck, runs alongside the shoulder, bicep and forearm, enters the wrists and finally culminates halfway to the ring finger and the tip of your pinkie. The nerve is named after the long bone called the “ulnar” that constitutes your forearm and whose sharp, protruding edge forms your elbow. The bone locked with the ulnar is the humerus, which is the bone above your elbow.
Every nerve in our body is covered and protected by the very muscles that it innervates. The same is the case with the ulnar nerve: it is protected by the flesh and muscles that form your bicep, forearm, ring finger and the pinkie. However, between the humerus and the forearm there exists a void, what is called the cubital tunnel, where the nerve is the most vulnerable: while passing through the cubital tunnel, it finds itself protected only by skin and some fat.
When you hit your funny bone against something, the unprotected nerve is pressed against the bone. It is the squeezed or irritated ulnar nerve that spouts the waves of pain, emitting the “electric shock”. The waves terrorize the regions innervated by the nerve: the forearm, the pinkie and half of the ring finger.
Cubital Tunnel Syndrome
Technology cannot progress without innovation. Throughout the generations, torturers have discovered novel techniques and devised more sinister ways to punish their subjects. However, none of them realized that the cruelest act requires only a chair and a stick. To constantly hit a subject’s funny bone is to inflict the worst of agonies. This is the stuff of nightmares (or revenge fantasies), but as it turns out, for some unfortunate people, that nightmare is a reality.
The ulnar nerve is squeezed every time we fold our arms while sleeping. The result, as we know, is pain, a funny sensation and slight numbness. However, progressive irritation may cause the effects to persist even after the arm has been unfolded. The continual pain and numbness weaken the forearm’s muscles and can often cause the pinkie and ring finger to curl. The hand then assumes the shape of what is called an “ulnar claw”. This awful condition is called cubital tunnel syndrome and abating it may require hand therapy, or in extreme cases, surgery!