Editor's Note: When you see these three dots surrounded by a gray rectangle — 1 — you can click on it to get further information about the topic. Click a second time, and the message goes away.
The Structure of the Wrist
There are 27 bones in the human hand which include:
- 14 phalanges (proximal, intermediate and distal) of the fingers 2;
- 5 metacarpals that connect the fingers to the wrist; and
- 8 carpal bones that, arranged in two rows, form the wrist.
Fingers are an excellent source of tactile feedback for us; they have the greatest positioning capability of the body. Each hand is dominantly controlled by the opposing brain hemisphere; thus, the preferred hand choice for single-handed activities such as using a pencil or scissors reflects the specific brain function of that individual.
The Function of the Wrist
Our fingers and thumbs all have a skeleton of phalanges which are joined by hinge-like joints. This gives us flexion toward the palm of the hand. Our fingers and thumbs also have a nail at the end, and fingerprint ridges on the other side.
However, the thumb is the only digit that:
- Is opposable to the other four fingers;
- Has two phalanges rather than three;
- Has greater breadth in the outermost bone than the bone closest to the hand; and,
- Is attached to a very mobile metacarpus (which allows us most of the opposability).
We have great mobility in our hands: We can move our fingers and thumbs in a variety of ways which assists us with picking up and holding on to items and doing a myriad number of tasks from knitting to using a hammer.
It is in the joints of the hand that we sometimes first notice the signs of aging, as these joints are vulnerable to arthritic stiffening and pain. To keep our hands as mobile as possible, it's important to exercise them, just as we do all the other parts of our body.
Some possible activities to assist in keeping your hands mobile (many can be done while watching TV or reading a book):
- Open and close the hand, making a fist and then opening the hand up as wide as it will go;
- Bend each finger individually (you can use your other fingers to bend a finger down if it will not do it by itself);
- Pay special attention to the thumb and move it through its full range of motion.
- Press your fingers and thumbs on to a hard, firm surface. Release and repeat several times.
- With a finger on your right hand, press down on a finger on the left hand. Repeat for all fingers.
- With one hand, grab the fingers of the other hand and pull back and then rotate the wrist through its full range of motion.
- Using a small sponge or a soft ball, squeeze the object with your hand several times.
The Structure of the Ankle
The ankle is the region where the foot and the leg meet. The main bones of the ankle region are the talus (in the foot), and the tibia and fibula (in the leg).
It includes three joints:
- the ankle joint proper or talocrural joint; this is a synovial hinge joint that connects the distal ends of the tibia and fibula in the lower limb with the proximal end of the talus 3;
- the subtalar joint which allows inversion and eversion of the foot 4; and
- the Inferior tibiofibular joint which connects the tibia and fibula.
The Function of the Ankle
The ankle joint allows us to move our foot up and down and side to side. It assists us in standing, walking, or running. Consider, for a moment, how important the flexibility of our foot is needed in every step that we take. Our feet get a lot of wear and tear over the years — walking, hiking, running. It's wise to take care of them.
Here are some simple exercises to help you to keep your ankles strong:
- While sitting in a chair, rotate the ankle to its full range of motion. You can use a stretchy elastic rope to help you.
- Stand on your toes and move back and forth.
- Tap your toes.
- Place books on the floor and put your toes on them while your heels remain on the floor. Hold.
- While sitting, extend your leg and spell out your name with your foot.
- If you have an elastic band or rope, wrap it around a strong piece of furniture so that it makes a loop. Put your foot in the loop and pull to the side. (Remember to do both directions.)
Other articles about joints:
- The Hip Joint
- Hip Replacement
- Is the old wives' tale true: Does your arthritis forecast tomorrow's weather?
- Joints and Exercise
- The Knee Joint
- Knee Replacement: The Basics
- The Shoulder Joint
I am a BCRPA-certified fitness instructor in Vancouver, BC. I teach four classes at the West End Community Centre in Vancouver, BC, mostly designed for the older adult. The Inevitable Disclaimer: Everything published here expresses only my opinion, based on my training and research. What you do with the information is entirely your own responsibility. I am not liable for any injury you suffer that seems to be related to anything you read here. Always consult your doctor before beginning an exercise program. For other articles, return to the table of contents.
These three dots behave exactly like a footnote. Click on them and you will get more information about the topic. ↩
Proximal means that it is situated nearer to the center of the body or the point of attachment. Distal means that it is situated away from the center of the body or from the point of attachment. ↩
The talus is sometimes referred to as the ankle bone. ↩
Inversion and eversion refer to movements that tilt the sole of the foot away from (eversion) or towards (inversion) the midline of the body. ↩