What is a joint and how does it work?

A joint is where two or more bones meet and is made up of a number of different parts that all work together so that we can bend, stretch, twist and turn easily – but within certain limits. Most of our joints are designed to allow bones to move only in certain directions.

The ends of your bones are covered in a thin layer of cartilage. This cushions the joint and helps to spread the load evenly when you put pressure on it. Its smooth, slippery surface allows your bones to move freely, without friction.

Surrounding the joint is a tough, fibrous sleeve called the capsule, which stops your bones from moving too much. The inner surface of the joint capsule (the synovium) produces a thick fluid that nourishes the cartilage and lubricates the joint.

Within or just outside the joint capsule are ligaments that help to hold the joint together and prevent it dislocating. The bursa helps to reduce friction in the joint.

At either side of the joint, your muscles are attached to the bones by tendons. As your muscles contract, they pull on the bones to make the joint bend, straighten or rotate.

An illustration of a cross section of a joint, including the bones, muscle, cartilage and ligament.

Why do joints ache and hurt?

There are many reasons why your joints may ache and hurt, including:

Inflammation inside the joints

Inflammation irritates the nerve endings and causes pain.

Worn or damaged cartilage

Cartilage has no nerve endings so you may not know if it’s damaged. But if your cartilage is badly worn, the bone underneath may also begin to wear and change shape. This can be very painful because your bones do contain nerve endings.

Putting extra pressure on your joints

Not surprisingly, carrying heavy items can increase the pain in your hands, arms and shoulders, but you may also feel the effects in other joints. But being overweight will further increase the pressure on these joints.

Extra activity

Pushing yourself to complete a task can cause you more pain the next day. Arthritis can reduce your muscle stamina so you become tired more quickly. Arthritis can also cause your ligaments to become slack, which puts more strain on your muscles and joints.

Inflammation in the structures around your joint

Inflammation may occur:

  • in a bursa, which normally allows your muscles and tendons to run smoothly over your joints – this often happens in your shoulder and hip joints
  • in the ligaments that hold your joints together – this frequently happens around your knee joint.

Referred pain

Sometimes you may feel pain in one part of your body when the problem is somewhere else. An example of this is sciatica, where a nerve in your back is injured but you often feel the pain in your leg. Your doctor or therapist will try to work out the cause of the pain and help you decide which treatments will help to ease your symptoms and/or control the condition.

Aside from medical treatments, there are lots of things that you can do for yourself to reduce the pain and strain on your joints and to improve your muscle stamina.

Why do joints become damaged?

There are three main things that keep your joints stable. These are:

  • the close fit of your bones
  • the capsule and ligaments, which are like strong elastic and keep your bones together
  • the muscles and tendons that make your joint move.

If you have arthritis, several parts of the joint can become damaged.

An illustration of what happens to structures in a joint when it develops arthritis and becomes damaged.

Your bones and cartilage may be damaged and your muscles may weaken, causing the joint to become unstable. This means that the joint may gradually change shape and deformities can develop.

Joint damage in rheumatoid arthritis

If you have rheumatoid arthritis your ligaments may become stretched and slack because of repeated swelling of the joint. These changes may start quite early in the condition.

The way you use your joints can contribute to the development of deformities. Your hands are particularly at risk because of their many small joints and constant use. These deformities can cause problems with activities that need a good grip. Common deformities in people with rheumatoid arthritis include:

  • your wrist or knuckles slipping downwards so that they partially dislocate (subluxation)
  • your fingers bending over towards your little finger (ulnar drift)
  • your finger or thumb joints buckling (swan neck, boutonniere finger or z-shaped thumb deformities).

About half of all people who have rheumatoid arthritis will have developed some hand deformities after about five years, so have a look at your own hands carefully and see if any of them have started to happen.

An illustration of typical hand deformities that can be caused by rheumatoid arthritis.

Joint damage in osteoarthritis

If you have osteoarthritis, which is a wear and repair process, knobbly fingers (Heberden’s nodes and Bouchard’s nodes) are common types of deformity. You may also notice reduced movement and pain at the base of your thumb. This is often associated with buckling of the main thumb joint.

If you notice early that any of your joints are becoming deformed, whether you have rheumatoid arthritis or osteoarthritis, you can change the way you do things to reduce the strain on them.

An illustration of typical hand deformities that can be caused by osteoarthritis.

Using joint protection techniques

The way you use your joints can increase the aches, pain and strain that you feel and, over time, it can increase any deformity. This is why you should take notice of pain. Listen to your body – if you’re still having pain an hour after an activity, try taking more short breaks next time.

Many people will give up an activity if it hurts (for example gardening), but it’s better to do a little at a time, with plenty of rests, rather than give up something you enjoy.

Try using some of the techniques below to help you to protect your joints.

Use splints and supports

Wearing splints can often help to ease the strain or pain in your joints. There are two types of hand and wrist splints.

  • Working splints (elastic wrist and thumb splints) provide more flexible support to help reduce pain while you’re working.
  • Resting splints consist of a custom-made cradle with straps to hold it in place. These can help if you have pain at night which affects your sleep or if you need to rest your hands for a short time during the day.

Some people find that compression (isotoner) gloves are also helpful in reducing pain and swelling and are easier to wear. These can be worn day or night, when working or resting.

A hand therapist can explore the options with you.

An illustration of different types of working and resting splints for hands and wrists.

Following all the suggestions in this section would be a lot to change all at once, and changing the habits of a lifetime can be difficult to do.

It’s a good idea to change things bit by bit. You might find it helps to write down the benefit you’ll get from making the changes. You could set yourself a goal each week to change two or three things – start with something that’s causing you most pain and try following the steps:

  • Work out another way of doing the task which causes less pulling or pain on your joints.
  • Practise the new movements until you get them right and feel comfortable doing them.
  • Keep practising until the new movements become automatic.
  • If possible get a friend or a family member to remind you if you slip into bad habits.

Avoiding tiredness

Try some of the tips below to help you avoid tiredness.

Organise and pace yourself

To help you avoid tiredness, look at how you’re doing things and see if you can organise a job better. Ask yourself the following questions:

  • Do you have everything you’ll need to use nearby before you start?
  • Can you cut out any part of the job or do it more efficiently?
  • Can you sit rather than stand to work?
  • Can you slow down a bit?

Store things where you can reach them more easily. Organise your cupboards with the things you use most often at the front and get rid of things you don’t use.

Think also about pacing yourself. The best ways to do this are:

  • taking a break for a few minutes every half hour
  • changing activities regularly and switch between light and heavier jobs.

After vacuuming a room do some dusting, then sit down and have a rest. When mowing the lawn, take a break before you get tired, change to a lighter job and go back to mowing later when you feel rested. Use the same approach at work. Taking regular short breaks actually means you can keep going for longer.

Keeping fit and healthy

Keeping fit and healthy is an important part of looking after your joints. You can do this by exercising, eating a balanced diet and taking care of your body.

Exercise

Exercising helps to keep your muscles strong and your joints moving. You can even exercise without putting strain on your joints.

Joint protection and exercise work together. Joint protection reduces strain on your joint capsule and ligament, which can become slack if you have arthritis, and straining them can make this worse. Exercise strengthens the muscles around your joint so that they can help to support it.

Who else can help me to look after my joints?

You don't have to start using joint protection techniques on your own. Healthcare professionals, local groups, and friends and family can all help to provide support and encouragement.

Healthcare professionals

The healthcare professionals attached to rheumatology units help support people in adapting their lifestyle. This can include:

Your occupational therapist can discuss the information in this section with you and suggest more ways you can reduce aches, pain and strain, which may help to slow down the development of joint deformities.