Why Does My Knee Hurt When I Run?

Whether you're training for your first 5K, preparing for a marathon or simply enjoy running to stay fit, knee pain can quickly take the enjoyment out of your training. It's one of the most common complaints among runners, but the good news is that most cases can be managed effectively with the right diagnosis and treatment.

The key is understanding that knee pain isn't always caused by a problem within the knee itself. Often, it's the result of several contributing factors working together.

Common Causes of Knee Pain When Running

There are several conditions that can cause knee pain in runners. Identifying the location of the pain can often provide clues, although a professional assessment is needed for an accurate diagnosis.

Runner's Knee (Patellofemoral Pain Syndrome)

Runner's knee is one of the most common running-related injuries. It typically causes a dull ache around or behind the kneecap.

You may notice symptoms when:

• Running downhill

• Climbing or descending stairs

• Squatting

• Sitting for long periods with your knees bent

The condition often develops gradually rather than after one specific incident.

Iliotibial (IT) Band Syndrome

Pain on the outside of the knee is commonly associated with IT band syndrome.

Symptoms often:

• Begin after a certain distance when running

• Ease once you stop

• Return when you run again

• Feel sharp or burning along the outside of the knee

It is particularly common in long-distance runners and those who have recently increased their training.

Patellar Tendinopathy

Often called jumper's knee, this condition affects the tendon just below the kneecap.

Pain is usually:

• Located beneath the kneecap

• Worse during running, jumping or squatting

• Tender when pressed

Although it's common in jumping sports, runners can also develop this condition.

Meniscus Irritation

The meniscus is a piece of cartilage that cushions the knee joint.

Meniscus irritation or injury may cause:

• Pain during twisting movements

• Swelling

• Clicking or catching sensations

• Occasional locking of the knee

This is less common in overuse injuries but can occur after awkward movements or falls.

Why Does Knee Pain Develop?

Running places repeated forces through the knee, but the body is designed to cope with these loads. Problems often arise when those forces exceed what the tissues can comfortably tolerate.

Several factors may contribute.

Training Too Much, Too Soon

One of the most common causes of running injuries is increasing training too quickly.

Examples include:

• Suddenly increasing weekly mileage

• Running faster without gradually building up

• Adding extra training sessions

• Returning to running after a break without easing back in

Your muscles, tendons and joints need time to adapt to increasing demands.

Weakness Around the Hip

The muscles around the hips and pelvis play an important role in controlling the position of the knee during running.

Weakness in the gluteal muscles can lead to altered movement patterns that increase stress on the knee joint.

Reduced Ankle Mobility

Limited ankle movement may change the way force travels through the leg, increasing the workload on the knee.

Improving ankle mobility is often an important part of rehabilitation.

Running Technique

Running style varies between individuals, and there is no single 'perfect' technique.

However, certain movement patterns may increase stress on the knee, particularly when combined with weakness or fatigue.

Recovery

Recovery is where your body adapts to training.

Without enough rest between sessions, tissues may not have enough time to recover, increasing the risk of overuse injuries.

Should You Keep Running?

The answer depends on the severity of your symptoms.

You may be able to continue running if:

• Pain is mild

• Symptoms don't worsen during the run

• Pain settles within 24 hours

• Running isn't causing you to alter your technique

However, you should consider reducing or stopping running temporarily if:

• Pain becomes progressively worse during activity

• You develop swelling

• The knee feels unstable or gives way

• You're limping

• Pain is affecting everyday activities

A healthcare professional can advise on appropriate activity modification based on your specific injury.