GRASPING THE IMPORTANCE OF OUR HANDS

GRASPING THE IMPORTANCE OF OUR HANDS

Grasping the Importance of Our Hands

Our hands do so much for us. They are capable of a wide variety of functions: touching, grasping, feeling, holding, manipulating, caressing, and more. They are a vitally important part of who we are and how we see ourselves.

We caress the hair of a loved one
Even when we’re talking, our hands are a key part of who we are and what we say. Many of us use our hands to help express ourselves while we’re talking. There’s an old joke: “If you want me to stop talking, tie my hands!” You probably know people who can’t talk without using their hands for visual aids. You might be like that yourself. Our hands play such an important role in how we communicate, we even use them regularly in figures of speech. Common phrases include: “touching on an important point;” “grasping a concept;” “getting your arms around an idea;” “taking a hands-on approach;” “fingering the bad guy;” and “reading a map like the back of your hand.” And, of course, the hands literally do the talking when a person uses sign language. When I think about the differences between our upper and lower limbs, I’m reminded of the song “These Boots Are

Made for Walking” by Nancy Sinatra. That’s because, in essence, our legs are made for walking. Our hands, however, do so much more. The hand is an amazingly multifaceted “terminal device” located at the end of the arm. You can compare it to the end piece

on a big erector set. Your shoulder, upper arm, elbow, forearm, and wrist are all part of a biological erector set. They are designed to put your hand where you want it to be, doing what you want it to do. They not only put the hand into the positions you want, but they also lift, rotate, and stabilize it.

The physical space in which we move our hands, their global sphere of motion, exceeds our “personal space,” as illustrated in Figure 1.

Our hands can perform extremely gentle and precise actions such as writing a letter, painting a picture, threading a needle, or playing a violin. Our hands also enable us to perform heavy labor, such as digging with a shovel, swinging an ax, using a jackhammer to drill through concrete, or pounding

a railroad spike with a sledgehammer. We use our hands to feel whether something is rough or smooth, hot or cold, sharp or dull. We hold a child’s hand as we cross the street.

We can extend our hand beyond where it normally reaches by thrusting our shoulder and arm forward. We can lean back to reach far behind us. Your legs work within the plane of your body, within the plane of walking. Sure, it’s cool to be able to bring your foot up behind your head, but, unless you’re a ballet dancer, you don’t need to do that. But there are many times when you need to place your hand behind your head, such as for grooming, or to stretch forward to grasp something that’s out of reach. To take off your shoe, you need to get your hand to your foot. It’s this incredible ability for hand placement that helps highlight a big difference between the abilities of the hand and foot.

The Brain, Body Image, and Saying “Hello”

The brain dedicates a lot of “space” to the face and hands. The illustration of the little man in Figure 2 helps show the parts of the body that the brain is most concerned with. Note how the hands and face are especially emphasized. That means a large portion of our gray matter is devoted to those things and functions about the face and hands, the two leading characteristics of our body image.

Think about it. We’re more likely to show the world our face and hands than any other part of ourselves. When I look around a lecture hall while giving a talk, the audience’s faces and hands are always visible. If the weather is warm, some might be wearing shorts so part of their legs are visible. A sleeveless blouse reveals more arms. But what we typically see of other people most often are the face and hands.

People may have different beliefs, opinions and traditions through- out the world, but one universal element of our humanity is that people in so many different cultures and walks of life use their hands to greet one another. In the West, this usually involves shaking hands with another person. A handshake can mean either “hello” or “goodbye.” Historically, it’s also a way of showing another person you’re not concealing a weapon in your hand. The handshake not only conveys a greeting, it lets another person know whether you’re friend or foe.

Elsewhere, people greet each other with their hands extended, palms together. This can be a gesture of “welcome” or “farewell.” It also can convey another message.  In some parts of the world, leprosy (Hansen’s disease) still exists. When this micro bacterium attacks

the nerves, it often results in muscle atrophy in the hands, creating a visible hollow between the thumb and index finger. In some cultures, extending your hands may

show another person that you don’t have leprosy. The gesture says, “My hands are healthy, so I am healthy.”

No matter the culture or social context, our hands and faces are parts of the way we present our- selves to others. A smile is intended to convey warmth and friendliness. An extended hand or hands are designed to be immobile.

Surgery and Decision-Making

There are significantly different schools of thought concerning amputation surgery or salvage for an upper or lower limb. When deciding whether to embark on a course to salvage a severely injured leg or choose amputation, the leading consideration is whether the person will be able to walk on

the injured limb and whether it can support his or her body weight. If not, amputation may offer a course that will reduce pain and enable the person to undergo prosthetic rehabilitation. With upper limbs, it can be difficult to tell early in the surgical decision-making process

whether the hand will retain some aspects of grasping and positioning if salvage is attempted. My view is that, generally, if the

person can retain some grasp and positioning ability, it is beneficial to attempt to save an upper limb because it probably will be more useful than a prosthesis. It’s not unusual to wait, even for years, to see how much useful function actually returns before deciding whether to proceed with an amputation.

Pain and Upper-Limb Amputations

Unfortunately, many people with upper- or lower-limb amputations experience amputation-related pain. In my practice, people with upper-limb amputations seem to have more vivid and intense amputation-related pain problems. This pain can be caused by neuro- mas, the mushroom-shaped growth of nerve endings that often scar at the end of severed nerves. Neuromas in the arm tend to be far more sensitive and irritated by pressure than neuromas in the leg. Also, while people with either upper- or lower-limb amputations may experience phantom pain, the pain tends to be more vivid and intense in the upper limb. Often, positional phantom pain involves a feeling that the missing hand and wrist are forced into a severely flexed grip position.

As previously discussed, pain in the upper limbs for people with amputations may stem, in part, from the amount of space the brain devotes to our hands. Simply put, our brains may be more focused on our hands. Plus, the hand typically has more sensitive nerve fibers. For example, we use our hands to feel whether something is hot or cold, smooth or rough, sharp or dull because the sensation of touch is strongest in our fingers and hands. Our hands are at the end of the “erector set” of our arms, so they’re designed to be used for touch as well as placement and grasping.