Have you ever thought about how amazingly complex our hands and wrists are? Just think, how much work do we do with these two hands throughout the day? From holding small objects, to writing, to lifting weights, we cannot do anything without these two hands. Inside these two seemingly small parts, there are many very complex and very important things. So, today we will talk about these wonderful hands and wrists in a simple way that you can understand.
What are the hands and wrists called? What happens to them?
Simply put, your hand and wrist are two very important parts of your body. They help you touch, manipulate, and feel things around you. When we think of touch , they're the first things that come to mind, right?
This hand and wrist are what help you with everything you do throughout the day, from holding something with your fingers, to picking it up with your hands, to using it. Just think, from eating to using your phone, to opening a door, to writing, how would you do all of this without these two?
Where are our hands and wrists located? How are they formed?
Your wrist is the lower part of your forearm, the joint between your arm and hand. It's like a hinge. It's what allows you to bend and turn your hand in any direction.
The hand begins where the wrist ends. Your palm, fingers, thumb, all of these belong to the hand.
The way our hands and wrists are made is amazing. It's designed to allow you to bend, twist, and turn your wrist in any way you want, and to be able to grab and touch things with your hands.
Imagine you're in a game where you're holding a toy with one hand, like one of those hands in a toy store. Your hand is the 'claw' that holds the toy. Your wrist is like the joint in the machine that moves that 'claw' up and down and side to side. That's how our hand and wrist work together.
This structure, called the hand and wrist, has several layers of different parts stacked on top of each other. This is what allows it to move and function properly.
The main parts of the hand and wrist are:
- Bones (bones)
- Muscles
- Nerves
- Tendons
- Ligaments
- Blood vessels (arteries and veins)
- Lymphatic vessels
Now let's look at each of these parts in a little more detail .
Bones (bones) - the frame of our hands!
Bones are what give our hand and wrist their shape and strength, and they are the main support for them. All other parts are connected to these bones.
Hand bones
Did you know that you have 19 bones in your hand alone? These are divided into several categories based on where they are located and what they do:
- Metacarpals: These are the bones inside your hand that give it shape.
- Phalanges: These are the individual bones that make up the joints in your fingers and thumb.
- `Sesamoids`: These are very small bones that are embedded in tendons. They help the tendons move easily.
Wrist bones
Your wrist is a very complex joint made up of 8 small bones. These bones are arranged in two rows.
- Proximal row (on the back of your hand, closest to your forearm):
- `Scaphoid`
- `Lunate`
- `Triquetrum`
- `Pisiform`
- Distal row (on your palm side, below the wrist):
- `Trapezium`
- `Trapezoid`
- `Capitate`
- `Hamate`
The larger of the two bones in your arm, the radius, joins with the scaphoid and lunate bones to form the wrist joint. This is what allows the wrist to rotate and bend.
What is Carpal Tunnel?
Between these four bones, `Pisiform`, `Hamate`, `Scaphoid` and `Trapezium`, there is a round space inside the wrist, like a tunnel. This is called the `Carpal Tunnel`. Through this tunnel, 9 tendons, 4 ligaments and one main nerve go to the other parts of the hand. It is like laying cables underground to provide internet and TV to homes.
Muscles - strong and delicate in the hand!
Muscles are soft tissues made up of elastic fibers. The small muscles inside your hand (`intrinsic muscles`) and the muscles on the outside of your hand, in your arm (`extrinsic muscles`) work together to give your hand strength and dexterity .
Hand muscles
You have about 34 muscles in one arm! Doctors divide these into several groups:
- Thenar muscles: These are the muscles that control your thumb. You can feel them by touching the ball of your thumb on the side of your hand, at the base of your thumb.
- Hypothenar muscles: These muscles are located along the back of your hand, on the side of your little finger. They control the part of your hand opposite your thumb.
- Interossei muscles: These are located between the metacarpal bones of the hand. They help move the fingers from side to side.
- Lumbrical muscles: These muscles are located at the base of the four fingers except the thumb. They help to bend the fingers.
Based on the movements made by these muscles, we can identify two main types of grip :
- Power grip: This is where the grip strength in your hand comes from. Think of it like lifting a heavy box or opening a tightly sealed bottle.
- Precision grip: This is used to precisely grasp and manipulate small objects. In this grip, your fingers can work together with your thumb (also called an `opposable grip`) to grip something tightly. Examples include picking up a pen from a table or turning a wrench.
Wrist muscles
The muscles in your wrist are connected to the muscles in your arm. Their main functions are:
- Flexion: Muscles that help bend the wrist downward, toward the palm.
- Extension: Pull your wrist up, as if you were waving to someone in front of you to "stop."
- Adduction: Helps bend the wrist inward, toward the center of the body.
- Abduction: Helps bend the wrist outward, away from the center of the body.
Nerves - feeling and control!
Nerves control your muscles. They also help you feel different sensations and carry them to your brain. For example:
- Contact
- Temperature
- Pain
- Pressure
There are three main nerves that bring sensation to your hand and wrist:
- Radial nerve
- `Median nerve`
- `Ulnar nerve`
From these three main nerves, many smaller nerve branches branch off and spread throughout the hand and wrist.
Tendons - the bridge that connects muscles and bones!
Tendons are the parts that connect your muscles to your bones. They're like strong, flexible ropes . There are two main groups of tendons in your hand and wrist:
- Extensor tendons: Tendons that help extend and straighten the fingers, hand, and wrist.
- Flexor tendons: Tendons that help bend and unbend the fingers, hand, and wrist.
Ligaments - the bands that protect the joints!
Ligaments are another important type of connective tissue in the hand. While tendons are like ropes, ligaments are like thick rubber bands. Their main functions are:
- Helping joints move smoothly.
- Protecting joints from excessive bending.
- Keeping joints in the correct position.
Hand ligaments
There are several types of ligaments in our hands:
- Collateral ligaments: These are located along the outer edges of the fingers and thumb. They protect the joints from excessive side-to-side movement.
- Volar plate: These ligaments connect the first two bones (phalanges) of each finger. They run on the palm side, under the bones. They prevent the fingers from bending too far back when they are extended.
- Palmar fascia: This is a triangular-shaped, thick, ligament-like structure under the skin of the palm. The narrow side of the triangle is near the wrist, and it widens toward the base of the fingers. It helps keep the shape of your hand as you move it and prevents the skin from slipping when you hold something.
Wrist ligaments
The main ligaments in the wrist are:
- Ulnocarpal and Radiocarpal ligaments: These help to stabilize the entire wrist as it moves.
- Collateral ligaments: These are similar to the ligaments in the hand. They are located on either side of the wrist, along the outer edges, and help hold the wrist in place.
- Volar carpal ligaments: They help stabilize the underside of the wrist, that is, the palm side.
- Dorsal radiocarpal ligaments: These help stabilize the top, or back, side of the wrist.
Blood vessels - nourishment for the hand!
Your hand and wrist receive blood from two main arteries. The radial artery runs along your radius bone (near your thumb), and the ulnar artery runs along your ulna bone (near your little finger). These two arteries connect inside the hand in what are called "arches." There are arches on the surface and deep inside the hand. From these arches, small blood vessels branch off to supply blood to the fingers.
Lymphatic System - Removing waste!
Your lymphatic system is a network of tissues, vessels, and organs. It collects and distributes waste products from your blood plasma throughout your body. The excess plasma, which comes from the blood vessels in your hands and wrists, is collected by very fine lymphatic capillaries in your hands. These then connect to the large lymph nodes and lymph vessels in your upper arms.
What are the common diseases of the hand and wrist?
There can be many causes of pain in the hand or wrist. Some of the causes include:
- `Carpal Tunnel Syndrome`: This is a problem that many people suffer from. It is caused by the compression of the `Median nerve` that passes through the `Carpal Tunnel` we talked about earlier.
- Arthritis of the hand or wrist: This causes swelling and pain in the joints. There are different types such as Rheumatoid Arthritis, Osteoarthritis, and Psoriatic Arthritis.
- Tendinitis: Inflammation and pain of the tendon.
- `Trigger Finger` or `Trigger Thumb`: A condition in which a finger or thumb feels stuck and makes a clicking sound when bent.
- Dupuytren's Contracture: A condition in which lumps form under the skin of the hand, causing the fingers to turn inward.
How can we keep our hands and wrists healthy?
One of the best ways to keep our hands and wrists healthy is to avoid overusing them . Doing the same thing over and over again can lead to repetitive strain injuries.
Be careful of these things when playing sports or other physical activities:
- Wear the correct safety gear (e.g. a wrist support).
- If you feel pain during or after physical activity, don't "play through it."
- After strenuous activity , give your body time to rest and recover.
- Stretch and warm up before playing sports or exercising.
- Cool down and stretch after activity.
- Do not overextend or bend your arms and wrists.
Your hand and wrist are some of the most complex and important parts of your body. They are flexible and can move in a variety of ways, which is why you can do so many things you can't imagine. Many people rely on their hands and wrists for daily tasks.
Pain in the hand or wrist is very common. But, don't ignore it. If you feel new pain, or if the pain is getting worse, be sure to see a doctor. That way, you can treat a small problem before it becomes a big one.
Take-Home Message
Okay, so from what we've talked about today, it's probably clear to you how valuable and complex our hands and wrists are.
- Our hands and wrists have many parts, including bones, muscles, nerves, tendons, and ligaments , all of which work together to help us grip and move things.
- Important nerves and tendons pass through special structures like the `Carpal Tunnel` .
- We have two grip styles: Power grip and Precision grip.
- Diseases like `Carpal Tunnel Syndrome` and arthritis can affect these parts.
- It is very important to protect, exercise, and keep your hands and wrists healthy by not overusing them .
- Don't forget to seek medical advice if you experience any unusual pain or discomfort .
So, think a little more about these two wonderful hands of yours and take good care of them!
` Hand, wrist, bones, muscles, nerves, tendons, ligaments, carpal tunnel, hand structure, hand anatomy, wrist anatomy, carpal tunnel syndrome, hand pain
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