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Why does my knee hurt?

Knee wear and tear is a common issue which can impact day to day life and prevent you from doing the things you love. In the absence of any significant injury or trauma, you may find yourself wondering why your knee is painful. After a quick Google search, you might assume that ‘‘wear and tear” seems like the most likely culprit, but what does this really mean?

This guide will tell you all you need to know about non-traumatic knee pain: what it is, why it happens and how to manage the symptoms. 

“Wear and tear” is a term commonly used to describe a range of degenerative changes in the knee and includes (but is not limited to) osteoarthritis. Although osteoarthritis can affect almost any joint in the body, it often affects weight bearing joints such as the knees. We used to think that these changes were a direct result of overuse and getting older, but now we know it’s not quite that simple.

Recent research conducted by Versus Arthritis suggests that a more scientifically accurate and far less foreboding way to think about osteoarthritis is as a process of “tear, flare and repair.” Let’s break it down;


As we go about our daily lives, the cartilage in our knees will sustain tiny tears which under normal circumstances are repaired without causing any symptoms. There are many factors that contribute to the development of these micro tears and whether or not they cause any pain or stiffness in the joint. It’s a common misconception that age is the biggest factor in the development of osteoarthritis, when in reality there are multiple factors which all play a part in each individual’s experience of the condition. These include:

  • Biomechanics – altered loading of your knee, perhaps due to a previous injury or instability can affect the progression of osteoarthritis.

  • Genetics – osteoarthritis tends to run in families, although we don’t yet fully understand why.

  • Smoking – research shows that smoking tobacco is linked to decreased joint health and slower tissue healing times.

  • Other conditions – People who suffer from rheumatoid arthritis are more likely to develop osteoarthritis. We’ll discuss the different types of arthritis in more detail another time.


When the impacts of the above factors reach a certain threshold, an inflammatory response is triggered in the knee joint. Inflammation is the body’s way of signalling to the immune system to remove the impaired cartilage and stimulate the production of fresh cartilage to replace it. It is common for these flare ups to last between 6 and 12 weeks, so it’s important to have realistic expectations. Later, we will discuss some ways you can help manage your symptoms, so keep reading.


Even healthy cartilage constantly undergoes a normal cycle of breakdown and repair. Osteoarthritic changes occur in the knee when the natural degeneration of the cartilage happens at a faster rate than the production of new cartilage. In some cases this can result in a thinning of the cartilage, reducing its shock absorbing capabilities. The lining of the joint capsule may also thicken and produce more fluid than normal, causing the joint to swell.

How do I know if I have knee “wear and tear”?

The symptoms associated with knee osteoarthritis vary significantly from person to person, but may include:

  • Pain that increases with use and improves with rest.

  • Stiffness, especially first thing in the morning or after a period of prolonged sitting.

  • The knee may feel hot or tender to the touch or appear swollen.

  • Difficulty getting in and out or the car or a seat, using the stairs or even walking.

When experiencing these symptoms, it can be tempting to rely on X-rays or MRIs to find the source of your knee pain. Although they can provide a snapshot of the inside of the joint, they cannot reliably pinpoint what is causing the pain. In fact, a recent study showed that features of osteoarthritis were found in MRI images of up to 43% of people over the age of 40 with no knee pain at all! Physical examination alongside a thorough case history of signs and symptoms is often the most effective way of establishing potential causes for your knee pain. Speak to your doctor or Physiotherapist to make sure your diagnosis is accurate. The sooner relevant lifestyle modifications are made the better the prognosis, so don’t wait!

What can I do about it?

Although there isn’t yet a way of reversing osteoarthritic changes, if you start suffering from pain you don’t just have to put up with it. In fact, for the majority of people symptoms do not steadily worsen over time.

The management of osteoarthritis focuses on maximising your body’s ability to successfully adapt to the changes happening in the knee joint and controlling the inflammatory response that accompanies them.

We now understand that osteoarthritis is not an inevitable part of getting older and that there are usually a number of different factors that contribute to its development in each person. Now, clearly we can’t change our age, our genetics or the fact that we suffered that old knee injury, but we can modify our lifestyles to reduce symptoms and prevent issues in the future.

There is no ‘one size fits all’ approach in the management of knee osteoarthritis, but here are some steps you can take towards controlling you knee pain;

Get Active;

Many people think that using the joint will increase their pain and cause further damage; but in reality, movement is the best way to improve joint health and function. Not convinced? Think of the cartilage of your knee as a sponge. A sponge won’t perform at its best if it’s bone-dry or if it’s soaked in dirty dishwater! To keep the cartilage as healthy as possible, waste products need to be squeezed out and nutrients need to be pumped in as often as possible. Frequent activity helps keep the knee joint moving and prevents stiffness whilst providing it with vital nutrients. Not only this, but increasing your activity levels can help you maintain a healthy weight to help prevent weight-bearing joints such as the knees from becoming overloaded!

Get Strong;

As previously mentioned, osteoarthritis reduces the knee’s ability to absorb the forces of everyday movements. A fantastic way to counteract this is to build strength in the muscles that move and support the knee. This can be done in a number of ways. You could use your own bodyweight, or try adding resistance by using weights or resistance bands. Using a bike or exercising in water are good ways of challenging the muscles in the legs whilst reducing the amount of weight bearing in the joint. These can be effective ways of building strength whilst minimising discomfort. Why not give it a try and see what works best for you?

Get Support;

Don’t suffer in silence! If you haven’t done much in the way of exercise for a while, the thought of dusting off those trainers may seem pretty daunting. But never fear; whatever your goals, we’re here to help. At Optimi, we’re a team of sports and exercise medicine clinicians and scientists who specialise in restoring and optimising physical health. 

Hopefully you now have a better understanding of knee osteoarthritis and a new found confidence in our body’s amazing ability to heal and adapt. It’s never too late to turn things around and stop letting knee pain dictate what you can and can’t do.

For reference, and further reading:

Enhancing delivery of osteoarthritis care in the general practice consultation: evaluation of a behaviour change intervention –

Prevalence of knee osteoarthritis features on magnetic resonance imaging in asymptomatic uninjured adults: a systematic review and meta-analysis –

EULAR Recommendations 2003: an evidence based approach to the management of knee osteoarthritis: Report of a Task Force of the Standing Committee for International Clinical Studies Including Therapeutic Trials (ESCISIT) –