6 Common Causes of Knee Pain After Running + How to Fix Them

Our in-house strength and conditioning coach how to identify, treat and prevent common knee injuries.

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Knee pain after running is a common running injury. As a runner, you are likely to have had a knee injury yourself or know someone who has at some point.

In fact, research shows1van der Worp, M. P., ten Haaf, D. S. M., van Cingel, R., de Wijer, A., Nijhuis-van der Sanden, M. W. G., & Staal, J. B. (2015). Injuries in Runners; A Systematic Review on Risk Factors and Sex Differences. PLOS ONE10(2), e0114937. https://doi.org/10.1371/journal.pone.0114937that knee injuries account for a staggering 50% of all running injuries. 

Why is knee pain after running so common? A host of reasons, ranging from previous injuries, training methodology, running gait, and lifestyle factors. Put simply, the knees bear a large brunt of our impact when we run, and as such, it is important we take steps to look after them.

Unlike other running injuries such a plantar fasciitis, knee pain can be caused by a number of injuries, such as runner’s knee, IT band syndrome, patellar tendonitis, knee bursitis, a torn meniscus, and osteoarthritis. 

We’ll look at each one individually in order to best equip you with the tools to tackle them.

Over the years of working with runners, helping them get back out to the trails I understand that injuries can be really disheartening, stopping you dead in your tracks and leaving you sidelined for an unknown amount of time.

Consistent knee pain can really knock confidence as well.

Remember, injuries do heal. When treatment protocols are followed, knee pain can be manageable and preventable.

In this article, we will look at the following:

If you experience a sore knee from running, let’s get you better!

A person holding thier knee.

4 Common Training Mistakes That Cause Knee Pain After Running

There are four main causes of knee pain after running. 

#1: Training Methodology

Many runners, especially beginner runners, will increase their mileage too quickly before a runner’s joints and connective tissues are strong enough to handle the load.  

“Our cardiovascular and muscular fitness improves more quickly than the conditioning of our cartilage, ligaments, tendons, and bone. As a result, runners are more susceptible to overuse injuries,” says Dr. Joe Norton, a doctor of physical therapy. 

A 2002 review of 2002 running injuries2Taunton, J. E. (2002). A retrospective case-control analysis of 2002 running injuries. British Journal of Sports Medicine36(2), 95–101. https://doi.org/10.1136/bjsm.36.2.95found that 80 percent of the injuries were overuse-based. It is hard to pre-emptively predict when we are overtraining; by the time the dull ache has turned into acute pain, it is often too late.

For this reason, it is important that we have a degree of structure in our training. Catching the running bug is something we all know too well. We haven’t run for a couple of months, and before we know it, we’ve run five times in 1 week. Now, I’m not saying this is bad; we all have our reasons, but give the body a chance to catch up.

A person running in the fall.

Overuse is always relative to the runner in question. It depends upon the acquired stress and subsequent recovery. The good news here is you have complete control over how much you train and how much you rest.

To gauge whether you are over-training, here are a few things to consider:

  • Have I recently increased my running volume? If you are new to running, increase your volume slowly. Our progress should be gradual. What we can do in 2 months’ time would be too much right now. Allow your body time to strengthen. If you have been running consistently, check for recent inconsistencies or spikes in your training.
  • Have I recently increased my running intensityIncreasing intensity will put more strain on the body. Ensure you are doing sufficient amounts of low heart rate training to counteract the bouts of high intensity.
  • Have I changed my running environment? If you have recently incorporated downhill running, you will likely be placing extra stress on the knee joint.
  • How is my sleep? Try and get at least 7-9 hours of sleep per night; it works wonders. Our bodies strengthen when we rest, not when we train. Aim to wake up feeling rested. Is there anything in your lifestyle that may be hampering sleep? Excessive alcohol consumption, work stress, and excessive screen consumption can all lead to reduced sleep quality.
  • Have I introduced something new? Have I recently started cycling? Hill sprints? Doing strength and conditioning work at the gym? Great job. But allow yourself adequate adaptation time.
The bones of a knee.

#2: Muscle Weakness

A lack of strength is a major risk factor for running injuries. It is a double-edged sword that relates back to the capacity portion of overtraining and muscular imbalance, which results in excessive strain on particular locations of the body.

For example, if the muscles involved in hip abduction are excessively weak or tight, it can lead to increased hip internal rotation and knee adduction. Your hips can drop, and your knees turn in. This can cause excessive compression on the lateral femoral condyle.

If the muscles in our legs are generally weak, running will likely cause inflammation, as the force endured when running will be too much for the capacity of the muscles. Progressive strength training is usually the answer here, and we’ll provide some exercises later.

#3: Poor Running Form

There is no one-size-fits-all solution regarding running technique. We all have different bodies, and “correct” forms will vary slightly as a result. That said, there are better and worse forms and a few mistakes to avoid.

Runners’ feet should land softly under their center of gravity, as taking shorter, faster steps makes you a more efficient runner and reduces the impact on your joints.

A great cue to incorporate on your next run is to try to run quietly. You’ll likely notice that your landing becomes lighter, and your cadence increases naturally.

Studies show many running injuries can be attributed to poor pelvis and lower extremity alignment while running.

If you have someone local to you, I would recommend contacting a professional who can offer a running gait analysis. They can accurately identify if you will benefit from modifying your running technique.

A doctor looking at a knee.

#4: Running Shoes

Running shoes can have a powerful impact on how our body moves when we’re running and how much force it impacts.

Over time, running shoes gradually lose their support and ‘bounce.’  

If you are in the wrong shoes or old shoes, you may be putting too much stress on one area, such as your knees, leading to irritation. 

You should look to change out a pair of running shoes every 300 – 500 miles.

Why Running is NOT Bad For Your Knees

While we discuss knee pain when we run, it’s important to note that running is NOT bad for your knees. In fact, regular running actually strengthens the knee and protects against arthritis later in life, says Todd Buckingham, a lead exercise physiologist at Mary Free Bed Rehabilitation Hospital.  

“Just as lifting weights makes your muscles adapt and become bigger and stronger, running makes your knees and joints stronger by causing the bone and cartilage (the connective tissue separating your lower leg to your upper leg) to adapt and become stronger,” he explains. 

But this doesn’t mean the more you run, the stronger your knees will be. And, it doesn’t mean that you should run through knee pain. In fact, you should do the opposite. Stop, treat, and proceed cautiously. 

Related: Is Running Bad for Your Knees?

A person holding their knee.

The 6 Common Causes And Best Treatment For Knee Pain Caused By Running

#1: (Iliotibial) IT Band Syndrome

Where it hurts:

IT band syndrome (ITBS) is often characterized by moderate pain or discomfort near the outer side of the knee.

It is one of the most common knee injuries that runners experience, with an incidence rate estimated between 5% and 14%.

What causes it:

Up until recently, experts have thought ITBS was a result of friction and consequent inflammation from the ITB, slipping back and forth over the lateral femoral epicondyle.

However, there is little quality evidence to show that the ITB moves across the lateral femoral condyle. Therefore, friction-related inflammation cannot occur.

Instead, ITBS is now understood to be a result of compression of the fat pad and bursa tissue between the Iliotibial band and the thigh bone.

A person holding their knee.

How to fix it:

Manage symptoms of IT band syndrome by avoiding doing anything that irritates it; this should include an initial period of active rest. Avoid aggravating activities, but be mindful not to be passive in your rest.

Crosstraining activities such as swimming and cycling, alongside a progressive strength and conditioning program, will help you get back on track and stay there!

Be sure to adequately warm up before exercising.

If the pain is severe, applying ice and heat in 15-minute intervals, alongside non-steroidal anti-inflammatory drugs such as ibuprofen, may be effective in reducing inflammation in the fat pad during the early stages of treatment.

Always discuss the use of NSAIDs with your doctor before using them.

A person holding their knee.

#2: Runner’s Knee – Patellofemoral Pain Syndrome (PFPS).

Where it hurts:

Runner’s knee is often experienced as a dull ache or pain at or under the front or side of the kneecap.3Vora, M., Curry, E., Chipman, A., Matzkin, E., & Li, X. (2018). Patellofemoral pain syndrome in female athletes: A review of diagnoses, etiology and treatment options. Orthopedic Reviews9(4). https://doi.org/10.4081/or.2017.7281

Runners can also expect to experience pain behind the knee after running, pain when squatting, walking up and down stairs, kneeling, or sitting for a prolonged period.

What causes it:

Runner’s knee is caused by many things, such as weak quadriceps muscles, overpronation while running, or increasing mileage too quickly. 

The quadriceps work to stabilize the knee, and lack of strength can result in excessive movement of the patella. Runner’s knee is thought to arise due to deviation in the tracking of the patella in the trochlear groove of the femur.

Overpronation causes a compensatory internal rotation of the tibia that can cause inflammation in the knee joint.

How To Prevent Runner’s Knee:

To treat Runner’s knee, initially avoid anything that aggravates the symptoms. Slowly re-introduce movements as long as they don’t cause excessive pain.

Long-term progressive strengthening is essential for preventing injury in the future. Try to include specific strengthening of the quadriceps, hamstrings, and glutes.

You can utilize ice and heat in the short term. A runner’s knee brace may also provide relief. 

For a full run-down on Runner’s Knee check out – Runner’s Knee Explained: How To Diagnose And 9 Exercises To Treat It

Someone icing their knee.

#3: Patellar Tendonitis (aka Jumper’s Knee)

Where it hurts:

Patellar tendonitis hurts below the knee, where the patellar tendon connects the kneecap and shin bone, allowing you to fully extend your knee. 

What causes it:

Patellar tendonitis is most often caused by increasing mileage and/or intensity too quickly.

Without adequate rest, stress compounds on the patellar tendon, causing inflammation and subsequent pain.

Having weak or tight quadriceps (thigh muscles) or hamstrings makes it more likely that increasing the training load will cause excessive stress to the tendon.

How to fix it:

Once again, avoid activities that aggravate the patellar tendon. After a period of active rest, re-introduce low-load activities, progressively increasing volume and load.

Again, you can utilize ice and heat on the area. You can also wear a patella brace to reduce stress on the patella. 

Someone with a hurt knee.

#4: Knee Bursitis 

Where it hurts:

Knee bursitis is inflammation of a small fluid-filled sac (bursa.) It is situated above and inside your knee and on your kneecap.

However, the most common pain is over the kneecap, known as prepatellar bursitis, followed by Pes Anserine bursitis on the inner side of your knee below the joint.

It could be characterized by pain on the front of the knee while bent or inner knee pain after running.

What causes it:

A bursa is a small fluid-filled sac that reduces friction and cushion pressure points between your bones and tendons, muscles, and skin.

When they become irritated, they swell, causing pain. Irritation is usually triggered by increasing mileage or intensity too quickly. 

How to fix it:

Bursitis usually improves without intervention. Therefore, treatment is usually aimed at symptom relief.

You guessed it—rest, ice, and heat, alongside anti-inflammatories for pain. You can resume running when the swelling has subsided, but if the pain and swelling continue, seek the help of a healthcare professional. 

For long-term injury avoidance, try strengthening the knee.

Treatment such as cortisone shots and physical therapy may be needed in extreme cases.

A person sitting on a couch holding their knee.

#5: Meniscus Tear

Where it hurts:

A meniscus tear is when a piece of cartilage, laterally and medially, between your shin and thigh bones tears. A torn meniscus hurts and usually swells around the knee so you can’t fully extend your leg.

It is a very common knee injury.

What causes it:

A torn meniscus usually occurs from overuse or sudden movements like twisting or changing directions.  

How to treat it:

Meniscus tears do not always have noticeable symptoms, and you don’t always need surgery with a torn meniscus. If you’ve torn your meniscus, stop running until the pain and swelling subside. 

Treatment is usually conservative. Therefore try ice, heat, and NSAIDS if necessary. Resume running carefully. If it hurts, stop. In extreme cases, surgery may be needed.

Even if the meniscus doesn’t repair itself, it’s possible to resume running without aggravation

A person with a knee brace on.

#6: Osteoarthritis

Where it hurts:

If you are suffering from osteoarthritis of the knee, you will likely experience pain, swelling, and stiffness in and around the knee joint.

What causes it:

The lining of your knee joint, called the hyaline cartilage (which separates the bones,) begins to wear away from wear and tear, causing the bones to grind together. 

Levels of osteoarthritis can be mild, moderate, and severe. For most people, it is a normal process of aging. That said, there is a lot of scope to improve the symptoms you may be experiencing.

How to fix it:

While it may hurt to move, movement keeps the joints healthy and mobile, which can lead to less pain over time. Try running on softer surfaces and avoid sudden movements.

Muscle weakness, particularly of the quadriceps, is common in those suffering from osteoarthritis.4Baker, K., & McAlindon, T. (2000). Exercise for knee osteoarthritis. Current Opinion in Rheumatology12(5), 456–463. https://doi.org/10.1097/00002281-200009000-00020It is difficult to conclude whether this is cause or effect, but one thing is for sure: strengthening the muscles around the joint will have a positive effect on most people.

A person holding their knee.

When Should I See A Medical Professional For My Knee Pain? 

If your knee pain doesn’t improve or suddenly gets worse after a period of rest and at-home treatment, it’s time to seek the help of a physical therapist or healthcare provider to get you back to doing what you love—running!

If the pain is acute and unmanageable, they will be able to decide whether you are in need of over-the-counter medicines such as naproxen or other anti-inflammatory medication.

Even if the knee problems are manageable and the symptoms treatable, seek out a qualified physiotherapist, if you have the means, to help get the most out of a rehab program.

They will be able to take you through a thorough physical examination and can offer you a range of tests and treatments, such as X-rays, orthotics (shoe inserts), strengthening exercises, taping, and stretching exercises.

Do not run through pain, as that can make your knee injury worse and lead to a longer recovery time! 

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Ben is a qualified Personal Trainer and Sports Massage Therapist with a particular interest in running performance and injury. He has spent the last 9 years working with runners at his clinic in Brighton. Ben is a keen runner and avid cyclist. Evenly splitting his time between trail running, road biking, and MTB.

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