Knee Inflammation From Running | All You Need To Know About Runner’s Knee

runner with green high socks and black shorts

Knee inflammation while running that, in turn, causes pain around your kneecap is surprisingly quite common. As a matter of fact, research suggests that this happens to nearly 23% of the general population.(1)

And, given the frequency of this injury, I think it’s important you know more about it.

So, first and foremost, what is it?

What is Patellofemoral Pain Syndrome (Runner’s Knee)?

Otherwise known as runner’s knee, this syndrome is best understood with even a basic understanding of the joint’s anatomy. So, let’s start there.

Basic knee anatomy

Essentially, your knee is where your thigh bone (femur), kneecap (patella), and shinbone (tibia) come together to form a joint.

These bones are connected to each other via several soft tissues, including your muscles and tendons, ligaments, cartilage (menisci), and bursa.

All these parts work together to allow your knee to move fluidly while maintaining stability.

Now, if any of those parts aren’t working as optimally as they should, there’s a good chance it’ll cause knee pain.

Concrete examples would be fractures to any of those bones, or torn ACLs and menisci, arthritis, bursitis, and many other conditions.

Now, you might be asking:

Why do my knees hurt after running?

According to an article from the American Family Physician, the cause of patellofemoral pain syndrome (PFPS) can be classified into either of these 2 things:

  • Biomechanical issues, and
  • Overuse and/or overload

Biomechanical issues

These include muscular imbalances and deformities that cause abnormal interactions between your patella and femur. Hence, the term patellofemoral pain syndrome.

This abnormality leads to excessive pressure around and/or under your kneecap causing pain in those same areas.

Examples of muscular imbalances that may cause runner’s knee include:

  • Weak quadriceps and tight hamstrings
  • A tight iliotibial band muscle (i.e. iliotibial band syndrome)
  • Tight gastrocnemius muscle (i.e. tight calves)
  • Hip muscle imbalances

Non-muscular biomechanical issues include:

  • Having flat feet
  • Having feet with higher arches than normal (the opposite of flat feet)
  • An abnormally rotated hip (either internally or externally rotated)

Most of these don’t directly involve the knee but they’re still very much capable of starting a chain of physical adjustments that, unfortunately, compromise the biomechanics of your knee.

For example, having internally rotated hips will likely also mean that your knees are rotated more towards the middle. This alters the way your kneecap adjusts with movement, possibly causing pain.

This is partly also why women are more likely to develop runner’s knee – because women naturally have wider hips that rotate more towards the midline.(2)

Also, overuse injuries generally go hand-in-hand with biomechanical issues

This is because those issues likely won’t cause any problems unless you overdo certain activities.

I, for one, have had flat feet since I was a child and I’ve never had any injuries until I played significantly more basketball the moment I got to college.

This isn’t isolated to just sports though. Normal daily activities, like running, walking, and climbing the stairs can cause runner’s knee as well, especially when you suddenly do more of them.

This brings us to the big question:

How do you fix runner’s knee?

RICE and anti-inflammatory medicine

RICE is an acronym for Rest, Ice, Compression, and Elevation.

Collectively, they prevent blood from pooling around your knee as well as help prevent any further injury which, in turn, helps fight off inflammation and knee pain.

Related: Ranking The Best Knee Sleeves For Runners

You may also take anti-inflammatory medicine as a complement to RICE.

However, some studies suggest that ice and pain relievers might delay the healing process despite offering pain and inflammatory relief.(3)

That being said, I highly recommend that you use these methods only if the pain and swelling prevent you from doing your daily activities.

Fix your imbalances with stretching and strengthening exercises

If it’s in the books for you, a few good physical therapy sessions should help speed things up, preferably with a therapist that has an affinity to the medical side of sports.

That being said, I’ve already mentioned some of the more common muscle imbalances that affect your knee (scroll back up to Biomechanical Issues). So, if you feel like you have either of those issues, they will most likely be fixed with exercise.

For example, the most common imbalance that I encounter with my patients is weak quads and tight hamstrings. To fix this, I focus their programs on stretching and releasing their hamstrings while strengthening the entire lower limb with emphasis on the quads.

Another crucial thing to remember is to make your hamstrings at least 50% as strong as your quads for your knees to be stable.(4)

So, if you can do 50 lbs on the leg extension machine, make sure you can do 25 lbs with your leg curls (the weight is relative, of course).

Related: Gentle Exercises To Fix Patellofemoral Pain Syndrome

Wear the right shoes or use orthotics

This applies specifically to those of you with biomechanical issues with your foot. These issues can also either be rigid or flexible, where flexible basically just means that you have normal arches whenever you don’t bear any weight.

Flexible foot deformities are also caused by certain muscle weaknesses and are therefore fixable with exercise.

In any case, both flexible and rigid cases can benefit from using the right shoes with the right arch supports because they automatically “normalize” the way your foot is positioned. In turn, this corrects the forces acting on your knee.

However, while this solution may seem simple, I urge you to also fix the muscle imbalances that may have caused them in the first place. It’s a more functional and long-term solution after all.

Surgery

This seems ominous but it’s rarely done and also the last resort when none of the above solutions worked. Go see a doctor or a physical therapist if your knee pain persists.

How can runner’s knee be prevented?

Well, fixing your imbalances and wearing the right footwear are among the best ways to prevent runner’s knee but here are a few other things you can do:

  • Warm-up before you run and stretch right after. (And, yes, stretch after your workouts; not before.)
  • Avoid running on hard and/or uneven terrain. Like concrete and banked roads, for example.
  • Lose weight if you have to. (Calculate your BMI here.)
  • Gradually increase the intensity of your exercises. For example, if you normally run about 30 minutes a day, don’t suddenly increase the duration to 60 minutes.
  • Get a new pair of shoes at least once a year or after you put 500 miles (800 km) on a pair. The American Orthopaedic Society for Sports Medicine says that running shoes retain less than 60% of their shock-absorbing capabilities after 250-500 miles. So, running in old shoes will only put more pressure on your knees.(5)

FAQs:

Does Runner’s knee go away?

Knee pain from PFPS usually goes away on its own if you stop running for a while. Recovery generally takes 4-6 weeks but it may take you longer or sooner than this.

To help the healing process go smoothly, you may also rest, ice, and wear compression sleeves or bandages on your knee joint. If your symptoms persist, please go see a doctor.

Is it OK to run with a swollen knee?

I highly recommend you rest a swollen knee.

Remember: swelling is a good indication of injury. It may or may not be serious but it’s always best to mitigate any risk.

If the swelling also comes with intense knee pain, limited range of motion, and decreased ability to bear weight on your leg, please seek medical attention.

What is the fastest way to reduce inflammation in the knee?

At home, the best way you can stop your knee from swelling more is to RICE it (rest, ice, compress, elevate) and maybe use anti-inflammatory medicine.

Technically, though, the fastest way to reduce inflammation is through joint aspiration but you’d need a doctor or a certified medical professional to do this.

Conclusion

If you were to have any takeaway from this discussion, I believe it should be this:

Runner’s knee – and all of its causes – is a common injury but it’s also one that can both be fixed and prevented with basic treatment. In summary, you’re going to want to work on balancing the strength and flexibility of your muscles, as well as wearing the right footwear (whether it be shoes or orthotics).

You also want to reduce the pressure you put on your knees while running by losing weight if you have to and avoiding uneven, harsh terrain.

If your symptoms still persist, consult your doctor and consider physical therapy.

Resources

  1. Smith, Benjamin E et al. “Incidence and prevalence of patellofemoral pain: A systematic review and meta-analysis.” PloS one vol. 13,1 e0190892. 11 Jan. 2018, doi:10.1371/journal.pone.0190892
  2. Boling, M et al. “Gender differences in the incidence and prevalence of patellofemoral pain syndrome.” Scandinavian journal of medicine & science in sports vol. 20,5 (2010): 725-30. doi:10.1111/j.1600-0838.2009.00996.x
  3. Dubois, Blaise, and Jean-Francois Esculier. “Soft-Tissue Injuries Simply Need PEACE and LOVE.” British Journal of Sports Medicine, vol. 54, no. 2, 2019, pp. 72–73. Crossref, doi:10.1136/bjsports-2019-101253
  4. Rosene, John M. et al. “Isokinetic Hamstrings:Quadriceps Ratios in Intercollegiate Athletes.” Journal of athletic training vol. 36,4 (2001): 378-383. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC155432/
  5. Cook, Stephen D., et al. “Shock Absorption Characteristics of Running Shoes.” The American Journal of Sports Medicine, vol. 13, no. 4, July 1985, pp. 248–253, doi:10.1177/036354658501300406