Human Anatomy

Why Are Opposable Thumbs Important?

Nidhi Nangia
By Nidhi Nangia. Updated: February 13, 2019
Why Are Opposable Thumbs Important?

Hold out your hand and carefully have a look at it: one thumb and four fingers. You, and many people, probably take their thumb for granted, but have you ever wondered what would have happened if you didn't have a thumb?

Did you know that you actually need your thumb to do and accomplish even the simplest everyday tasks. Most primates, including monkeys and apes, have opposable thumbs, but human thumbs can move farther across the hand than any other animal. Using your opposable thumbs, you can grasp anything easily, pick up little objects and eat with your hands. Here at oneHOWTO, let’s answer the question: why are opposable thumbs important?

  1. What do opposable thumbs do?
  2. Why they are called Opposable?
  3. Communication With Opposable Thumbs
  4. Interesting Facts about Opposable Thumbs
  5. Benefits of opposable thumbs

What do opposable thumbs do?

At first glance, thumbs do not seem to carry any significance. They don’t have any muscles, they have only two phalanges, they are short in size, and they are at a distance from fingers. As compared to its more beautiful, longer counterparts, thumbs seem to be quite insignificant. But the this could not be further from the truth. In fact, thumbs are arguably the most important components of your body. Not only do thumbs have physical power, but they have their own communication skills and symbolism . Want proof? Try to immobilize your thumbs for half an hour, and try doing your normal daily activities, such as: writing, bathing, making food, tying shoe laces, buttoning your shirt, driving etc. You will instantly get realize about how incomplete life would be without thumbs.

Why they are called Opposable?

First of all, let’s define the word ‘opposable’. Basically, ‘opposable’ describes something’s ability to situate itself against another thing. While looking at your hand, move your fingers and your thumb and see how differently your thumb moves than other fingers. Your toes and fingers are termed as digits, your thumb is the thickest and shortest digit you will see on your hand. You will notice that your thumb moves in different directions than your fingers. That is why thumbs are also known as opposable thumbs.

When we talk about human thumbs, they are able to lie across your palm, perpendicular to the fingers. Humans are the only mammals that have fully opposable thumbs . Primates have a powerful grip which they need to climb trees, grasp tree limbs and hold rocks for throwing. But since their thumbs lack full opposition, they don’t have a nice pincher grip like humans. At best, primate thumbs are opposable only to their index fingers, due to which they are able to peel bananas. On the contrary, human thumbs are longer, better controlled, more maneuverable, and they work like fine tuned machines. Although human thumbs do not have any muscles, they are controlled by 3 major nerves and 5 hand muscles. Hand attracts 25% of the motor power of the brain and 4% of it is dedicated to the thumbs. A human thumb can move in 6 different directions, making it superior in comparisons to thumbs of all other primates.

Why Are Opposable Thumbs Important? - Why they are called Opposable?

Communication With Opposable Thumbs

People use thumbs to indicate different things and meanings. They are often used as excellent communication devices. Let’s see how some people believe thumbs communicate:

  • You show appreciation to someone’s act by showing thumbs up.
  • If a person fails, you show thumbs down to indicate disapproval.
  • Thumbs shown sideways indicate uncertainty.
  • Some say that if you use your thumb to do something that other people generally do with their index finger, such as pushing a doorbell, then it denotes superiority.
  • If you keep your thumb tucked inside your palm, it can indicate loss of confidence, no intention of acting, and being held back by something.
  • If you point your index finger at someone and keep your thumb in the air, it indicates that you feel superior to the other person.
  • If you point your index finger at someone and keep your thumb sideways, it indicates that you feel you are equal to the other person.
  • When a person points their thumb to themselves, then it indicates that the whole agenda is about he person and they are the person in power.
  • Thumb kept at a short distance from your hand indicates insecurity and caution, medium distance indicates confidence and stability, and long distance indicates extreme confidence, aggression and being ready for action.
  • Handshake in which the thumbs of both people are pointing upwards indicates equal standing and good rapport.

Interesting Facts about Opposable Thumbs

  • Evolution of opposable thumbs helped primates develop better defense systems, such as grasping and throwing weapons etc.
  • You must have noticed that doctors check a pulse using their index and middle finger. This is because a thumb has a big artery which pulses, making it difficult for the doctor to feel the pulse using his thumb.
  • Some other animals that have opposable thumbs are chimpanzees, orangutans, some lemurs, giant pandas, and frogs like phyllomedusa. Though their thumbs are just an extra-long bone that they can use as a thumb.
  • If you happen to lose your thumb, microvascular surgery can enable your big toe to become your thumb. It functions exactly the same as your thumb. Once transferred to the hand, the surgeons bring life to your big toe by sewing together small veins and arteries.
  • In addition to grasping and pinching, thumbs can also rotate and flex. Strength and precision is achieved with this set of coordinated motions. So, it’s the thumb that makes turning, buttoning, writing and picking possible.
  • The thumbs appear to have two knuckles, but in reality, its third knuckle is situated right above your wrist, known as the first carpometacarpal joint. Carpometacarpal joint disorder is the condition in which this joint enlarges to look like a mass or bump. It is painful, and this condition can result in the loss of thumb mobility. Although surgery can relieve the pain, it’s almost impossible to restore your thumb back to complete mobility.
  • While thumb arthritis was previously more common in older people, it has now become more common among young people in their 30s and 40s. Frequent phone use is said to be largely responsible for this. Genetics may also be responsible for premature thumb wear. If someone in your family has this condition, they and you should take caution by avoiding repetitive activities that need gripping, such as holding phone for long periods of time, using an electric toothbrush, carrying milk jugs that have handles etc.

Benefits of opposable thumbs

Opposable thumbs not only impact our lives, but they also function as powerful communicators. Without thumbs, there would have been no written work, sculpture, paintings, music, electronics or anything. Thumbs are precious assets required for our survival.

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