How to Get Rid of Runner’s Knee - Part 1
You’re on mile 4 of your run. The road dips downhill. You’re feeling good and you open up your stride. You finish your run feeling great! Later as you walk downstairs, you feel an ache behind your kneecap. It disappears but then reappears on your next run and the run after that. Now it hurts even when you sit too long. Welcome to runner’s knee! It’s one of the most misunderstood injuries in the sport of distance running. This article tackles the most common myths about runner’s knee, explain what really causes it, and outlines a clear framework to help you recover.
What Runner’s Knee Feels Like
Runner’s Knee (AKA patellofemoral pain syndrome or PFPS) is just a fancy way of saying “pain around the kneecap.” It’s a very common injury, making up somewhere around 25% of all injuries in runners. I see it every single week. Here’s some common things I hear from patients:
Vague or hard to localize pain behind or around the kneecap
Pain worse with sitting too long, using stairs, or after running
Knee feeling weak or unstable.
No swelling.
Recent increase in workload. This might not just be running workload - it could be recent additions in weightlifting, biking, etc.
Note: if your knee is visibly puffy or swollen around the kneecap, it’s worth having it evaluated by a PT or sports physician to determine other causes such as patellar stress fractures, fat pad irritation, or patellar bursitis. The management of those conditions is different than outlined in this article.
Why Does Runner’s Knee Hurt?
Your kneecap has two jobs: increase the leverage of your quadriceps and protect the front of the knee joint. Your kneecap forms a joint with your thigh bone called the patellofemoral joint - where it slides along a groove in your thighbone.
The patellofemoral joint handles a lot of compressive (inwards) directed forces: more than 4x your body weight every time your foot hits the ground while running compared to walking. That’s normal, and the joint is designed to handle it - it actually has the thickest layer of cartilage in the entire body.
Joint cartilage, like what is behind your kneecap, doesn’t have nerves, meaning irritation stems from nearby tissue such as bone or other connective tissue near the joint. It’s worth remembering that pain is caused by our brains interpretation of input it perceives as potentially dangerous. In the case of runner’s knee, patients have pain with activities that cause increasing compression in the joint. Therefore, pain is caused by a sensitivity of the sensory tissue in your patellofemoral joint to compression. Your joint isn’t being damaged - it’s just becoming more sensitive to loading than normal.
If you’ve never heard pain explained this way before, I break it down in this article about pain and running injuries. Understanding the difference can be a game-changer when recovering from any kind of injury.
Let’s continue to break down what contributes to increasing sensitivity.
Myth Busting
If you search for runner’s knee advice you’ll still see outdated explanations from well-meaning therapists, physicians, and coaches everywhere:
“Your inner quad (VMO) is weak.”
”Your kneecap is misaligned or not tracking right.”
”Your glutes aren’t firing.”
”Your IT band and hamstrings are tight.”
”Your running form is faulty.”
Current research does not support any of these factors as predictors for runner’s knee. In fact, several studies support that the hip and knee weakness are a result of pain, not a cause. Furthermore, strengthening these areas hasn’t been shown to prevent runner’s knee. If someone is still trying to treat your knee pain by “realigning your kneecap” or spending a bunch of time trying to fix “soft tissue restrictions,” it might be time to seek out a more updated treatment plan.
What Actually Increases Your Risk
The most recent research on PFPS points to a different set of risk factors - it’s less about “how you’re built” and geared more towards how your body is adapting, or failing to adapt, to the training you’re doing right now. Your risk is personal, depends on your life environment, and is always evolving. Here are some of the current, most clearly identified risk factors for runner’s knee:
Having prior patellofemoral pain: between 50-80% of runners will have a recurrence.
Female sex: 2.23x more likely to experience.
Early sport specialization: athletes who specialize in sport early have a 150% greater risk.
Recent change in workloads: a recent workload spike doesn’t have to mean a huge jump in running mileage. It could be a new strength routine, too much downhill running, or even starting to bike to work every day.
It doesn’t stop there. General risk factors for running-related injuries, like poor sleep and low energy availability, also raise your risk, especially if your workload is high.
Here’s where that becomes meaningful in rehab and training:
A female runner who played club basketball at a young age, with a previous history of patellofemoral pain might respond very poorly to a block of training that loads the patellofemoral joint more than usual. In contrast, a runner with a similar profile - but who played multiple sports growing up and has never had knee pain - might tolerate that same block just fine.
This is why two runners with the same plan on paper can have very different outcomes.
What Helps Runner’s Knee Get Better
The good news is that runner’s knee generally gets better, but it needs active treatment to improve. It is not a self-resolving condition and can become persistent and frustrating if ignored.
If PFPS is driven by a sensitivity to compressive loading - not damage, poor alignment, or weakness - then rehab needs to reflect that. The goal isn’t to fix something that’s damaged, it’s to keep your pain down and desensitize your joint to load. And because running involves repetitive, moderate-range knee motion under load, your rehab should gradually emulate those demands.
Here’s the general framework I use with runners:
Keep Running (If You Can):
In many cases, runners don’t need to stop running completely. But you have to have a safe level of pain, and the key is to give the knee any advantage you can. That might mean:
Swapping out one weekly run during rehab to reduce total loading
Reducing your total mileage
Avoiding steep or prolonged downhills, as running on a 5% decline has been shown to increase knee loading by ~40%.
Increasing your step rate by 5-10%, which has been shown in biomechanics studies to reduce patellofemoral forces.
These are not permanent changes and certain strategies don’t work for everyone. They are temporary adjustments that buy you space to feel better and keep you running.
Progressively Exercise The Hip and Knee:
Exercise for the hip and knee has long been the gold standard for patellofemoral pain - doing both has been shown to result in greater reductions in pain. If you’ve read through my whole article, hopefully I’ve convinced you that the point isn’t to correct weakness or mechanics. You’re using movement to retrain your nervous system and desensitize your patellofemoral joint to loading. That being said, you do have to make the exercises progressively more challenging. Doing the same exercises at the same level will lead to a plateau at some point.
Why does exercising the hip help a knee problem? It isn’t crystal clear. Maybe it’s helping distribute load. Maybe it’s because you’re exercising tissue that has neurological connections to the patellofemoral joint and that helps desensitize it. Either way, it works, and it needs to be in your plan. Don’t just exercise the outer hip (abductors and extensors); literature supports working the inner hip (adductors and flexors) as well.
Minimize Highly Irritating Movements:
While squats, lunges, and plyometrics are a necessary part of rehab plans, how and when you do them is important. Early on, your knee may not tolerate deeper knee bending - the deeper you go into the motion, the more compression you put through the joint. Running only takes you through 30-40 degrees of knee bending, so it’s completely reasonable to limit depth early and reintroduce it later.
How Much Pain is Okay?
Considering the personal nature of pain, I do my best to avoid using numbers as guidelines. The statements below are based on my own clinical experience and backed by concepts presented in related research.
During and after exercise, your symptoms must remain in a “safe” range. This is something you would describe as uncomfortable, but tolerable. Any pain that crosses into “danger” territory or makes you limp is a no-go and you need to adjust what you’re doing or stop.
By the next morning, your symptoms should remain in that safe range or have reduced back to their baseline. If they’re worse, you pushed it too far and need to adjust your workout next time.
Week by week, your symptoms should get better. It should become less noticeable, less frequent, or less constant.
Runner’s knee isn’t something to fear, but it does require a smart, consistent approach. In part 2 of this series, we’ll dive deeper into what that looks like.
LEARN MORE:
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Neal BS, Lack SD, Lankhorst NE, Raye A, Morrissey D, van Middelkoop M. Risk factors for patellofemoral pain: a systematic review and meta-analysis. Br J Sports Med. 2019 Mar;53(5):270-281. doi: 10.1136/bjsports-2017-098890. Epub 2018 Sep 21. PMID: 30242107.
Richard W. Willy, Lisa T. Hoglund, Christian J. Barton, Lori A. Bolgla, David A. Scalzitti, David S. Logerstedt, Andrew D. Lynch, Lynn Snyder-Mackler, and Christine M. McDonough. Patellofemoral Pain. Clinical Practice Guidelines Linked to the International Classification of Functioning, Disability and Health From the Academy of Orthopaedic Physical Therapy of the American Physical Therapy Association. Journal of Orthopaedic & Sports Physical Therapy201949:9,CPG1-CPG95. https://doi.org/10.2519/jospt.2019.0302.
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Willy RW, Halsey L, Hayek A, Johnson H, Willson JD. Patellofemoral Joint and Achilles Tendon Loads During Overground and Treadmill Running. J Orthop Sports Phys Ther. 2016 Aug;46(8):664-72. doi: 10.2519/jospt.2016.6494. Epub 2016 May 12. PMID: 27170525.
Post WR, Dye SF. Patellofemoral Pain: An Enigma Explained by Homeostasis and Common Sense. Am J Orthop (Belle Mead NJ). 2017 Mar/Apr;46(2):92-100. PMID: 28437494.
Willy RW, Meira EP. CURRENT CONCEPTS IN BIOMECHANICAL INTERVENTIONS FOR PATELLOFEMORAL PAIN. Int J Sports Phys Ther. 2016 Dec;11(6):877-890. PMID: 27904791; PMCID: PMC5095941.
