It’s an obvious fact that our hands, the prehensile extremity of our arms, are vital to everyday function. Despite constant use, however, most people know little about their makeup or how they work. Below are some interesting facts that may come in handy:
1. Keeping it together: The system that allows your hands and arms to work is delicate and complex, much like the inner workings of a clock. When one of those pieces fails, it can put a halt to the function of the other pieces or the entire entity. In regards to the hand, the system is comprised of 29 joints, 123 ligaments and 27 bones (not counting the sesamoid bones, which differ in number from person to person). Those 27 bones include:
Five metacarpals (long bones) that connect the finger bones to the wrist bones
Eight carpals (the wrist bones)
Fourteen phalanges (digital bones) of the thumb and fingers
2. Let’s talk sense: As a part of a massive and intricate system of nerve and specialized touch receptors, your fingertips are able to recognize sensations such as pressure, texture, vibration, pain and temperature.In addition, the tips of your fingers are so apt at communicating with your brain that your consciousness is generally left out of the equation. For example: have you ever noticed that right before reaching for a beverage, your hand will assume the shape of a cup?
3. Finger puppets: Aside from the minuscule muscles in the skin that make your hairs stand on end (arrector pili); the fingers do not contain muscles.So how do they move?The fingertips are attached to 17 palm and 18 forearm muscles by tendons, which are what ultimately move your fingers. In short, your fingers are pseudo puppets that are controlled by the muscles in the bottom portion of the hand and arm.
4. Thumbs up: Contrary to popular belief, thumbs aren’t considered fingers. They are digits, but not fingers and they are responsible for 50 percent of the function of our hands. A lot of work goes into the control of this important opposable digit. In fact, nine individual muscles, all of which are managed by three major hand nerves, control the thumb.
5. Injury prone: Despite the strength and flexibly of the hand, it is also a delicate part of the body, making it susceptible to injury. Statistics regarding injury to the hand include:
One out of six disabling work injuries involves the fingers, most often due to the finger striking or being struck against a hard surface
One-fourth of athletic injuries involve the hand and wrist
Children under the age of six are at the greatest risk for crushing or burning injuries of the hand
