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Causes of knee pain

Knee pain is a common complaint and most of us will experience it at some point in our lives.

What causes knee pain? 

Knee pain could be a symptom of a medical condition such as osteoarthritis or bursitis. 

We share the many different causes of knee pain and how a consultation with a specialist could help diagnose your knee pain.

There are numerous causes of knee pain, some more common than you might think.

You may experience knee pain from the following:

  • knee pain when walking/ knee pain from walking too much;
  • knee pain when kneeling;
  • knee pain when bending;
  • knee pain running;
  • knee pain when lying down;
  • cycling knee pain;
  • throbbing knee pain at night;
  • knee pain when squatting, and
  • knee pain after fall.

The main cause of a sore knee joint in adults over 45 is osteoarthritis (arthritis-related knee pain), while in those under 45 it is injury. In both cases, it is most commonly mild and self-limiting. In these cases, self-management will often be all that is necessary. Below are listed some self–management strategies.

If it is a more severe pain or injury with swelling, inability to weight bear or loss of function, an opinion should be sought from your doctor, Physiotherapist or health practitioner. 

In the vast majority of cases, knee pain is a result of biomechanical factors, degenerative joint processes or traumatic injuries to the knee.

Some examples of inflexibility causing faulty biomechanics include inflexibility in the hamstring muscles at the back of the thigh or the calf muscles. This can result in excessive ankle and foot rotation known as pronation as well as increased knee flexion during activities such as walking, climbing stairs and during sporting activities.

Stiffness in the hip flexor muscles, iliotibial band and quadriceps muscles may result in excessive rotation at the hip and knee due to the pull of these structures on the outer sorry and knee. This can also result in a sideways tilted or upwards glide to the patella (kneecap), resulting in at patellofemoral pain.

The severity of the pain and its impact on our life varies for each person. Some people may find their knee pain is mild and resolves itself within a matter of days, while others will be in much more significant pain, unable to straighten or bend the leg without extreme difficulty and discomfort.

Here, we will look at some of the common causes of knee pain. The information below is intended as guidance only and is not intended to replace a personal consultation with a knee specialist.

When you first meet with your doctor, they will want to learn when your knee pain started and whether there was an obvious cause for it. Sometimes the cause is obvious, such as a hard knock or twist during a game of football. Other times, you may not know when exactly the pain started; it’s just there.

Nobody will be able to describe your knee pain better than you, and your doctor will listen carefully to what you tell them as they narrow down potential diagnoses. You may be able to point to the exact part of your knee where you have pain, or it might be a more generalised pain, harder to pinpoint but no less real.

The location of the pain can sometimes help with diagnosis, although pain in one part of the knee doesn’t always mean that the problem is in that specific part of the knee as the knee is a bad localiser of pain.

There are a number of reasons you may have pain in the knee. Some of the most commonly seen ones are:

Pain from a damaged meniscus

This can occur in sportsmen or non-sporting people and can occur at almost any age. In young patients this generally follows an episode of trauma while older patients tend to get a degenerative problem with the meniscus which results in tearing of the meniscus.


The joints in your body contain fluid-filled sacs (bursae) that act like the shock absorbers in a car, cushioning the joints from shock and impact. Inflammation or injury to the bursae can put increased pressure on the nearby tissues, causing pain and/or swelling. There are certain risk factors for developing bursitis in the knee, including:

  • age,
  • having a job where you kneel a lot, such as carpet fitter, electrician or nursery assistant.
  • a direct impact to the knee, usually when playing a sport like football or rugby.


Arthritis is a degenerative joint condition. In the knee, the most common type is osteoarthritis (also known as ‘wear and tear’ arthritis). Osteoarthritis causes the smooth cartilage on the joint surfaces to wear away more quickly than usual. In a healthy joint, the smooth cartilage helps the bones to move freely and smoothly over one another. In a joint with arthritis, the bones rub against each other when they move, causing increased pain and stiffness. Bending the knee can become harder, which often makes common movements such as sitting down and standing up slower and more challenging.

Ligament damage

Ligaments are strong bands of connective tissues. They connect bone to bone, helping to provide strength and stability to the joints. The knee has four main ligaments, and damage or injury to any of them can cause severe pain, as well as instability, in the joint. The most commonly injured ligament that needs surgical treatment is the anterior cruciate ligament (ACL), which is prone to tear when the knee joint is twisted or overextended. This is a common injury when playing sports like football or rugby, where quick changes of direction are needed. Medial collateral injuries are more common, but frequently just behave as a sprain and need little or no attention.

Runner’s knee

Despite the name, this is not a problem only for runners. Also known as patellofemoral pain syndrome, it is used to describe a dull pain in and around the kneecap (patella). The pain will often become worse after a lot of activity which involves the knee, such as running, squatting or walking up the stairs.

Significant trauma

Any hard impact or excessive twisting to the knee has the potential to cause damage to the joint and severe pain. The damage caused may range from a less-serious strain or sprain through to a dislocated knee or fracture of the femur, tibia, fibula or patella..

Certain conditions, such as arthritis, are usually seen more frequently in older patients, whereas ligament damage is more common in an active person in their twenties. Although not as common, knee pain can also sometimes be caused by different types of cancer.

There are of course exceptions to these examples, which is why a personal consultation with a doctor is so valuable

The underlying issue with any knee pain is to first find out exactly what is causing it. An accurate diagnosis will inform the treatment options. For example, if your knee pain is being caused by arthritis, the best treatment options for you will be very different to those needed for somebody with a torn ligament.

While each doctor will have their own personal way of diagnosing the cause of your knee pain, they will each follow a specific series of steps to arrive at a firm diagnosis. As well as a physical examination, they may need to carry out diagnostic tests such as an X-ray or MRI scan to help confirm the diagnosis.

Once the cause has been determined, they will be able to talk with you about treatment options and advise you on the best course of action to get you out of pain and back to normal again.

Knee pain is frustrating to live with, limiting your ability to do the things you love and preventing you from taking part in the sports or activities you enjoy.

We can help get you out of pain and back to doing the things you want. It’s easy to book a consultation online with one of our experts.

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