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Why Your Knee Hurts

“It’s 4:30am, you just woke up for your morning run. It’s a long 12-miler today, and you want to make sure you finish before the Texas heat melts you away. The first couple miles feel good, your pace is right on track. But around the 5th mile mark you start to feel a little pain in your knee. It starts as a little pressure behind the kneecap. You push on, but around mile 7 you have to really slow your pace. Mile 8 the pain travels up your leg into your quads. Mile 10 your calf starts to feel like it’s on fire. You finally finish all 12 miles, but your pace splits are atrocious, and you have to limp yourself back into your house with a swollen and hurt knee. Yet again, your painful knee has caused your performance to suffer. This has been going on for a few months now, and you can’t figure out how to get better. How are you going to run that half marathon in a couple weeks?”

Sound familiar? Knee pain can be due to any number of things, but many of you have likely been told you are dealing with Patellofemoral Pain Syndrome (PFPS). This is an often-used term in the healthcare and fitness industries. That’s because it is a very common issue that many people deal with. One study reports an incidence of 22.7% in the general population1. Almost one in every four people deals with PFPS in a given year. That number is likely even higher in runners. But what even is PFPS?

What Does it Mean?

· “Patello” – meaning the patella, or kneecap

· “Femoral” – meaning the femur, or thigh bone

· “Pain” – pretty self-explanatory

· “Syndrome” – a word that means a group of symptoms that commonly occur together

What it breaks down to: pain associated with the kneecap and thigh bone, that presents as a common group of symptoms.

What are the Symptoms?

· Pain in the anterior knee (often poorly defined- “my knee hurts but I don’t know exactly how or where”)

· Crepitus (cracking, crunchiness) and possible swelling

· Pain/stiffness after prolonged periods of sitting

· Pain with bending, squatting, running, ascending/descending stairs

Can You Fix It?

A knee in pain is a knee that is over-worked. But why would your knee be so over-worked? Your hips and ankles are not doing their jobs to help handle the load of running. Limitations in the biomechanics of the two joints surrounding the knee have led to movement compensations that place more strain on your knee than the knee can handle. This occurs with each step you take, over the course of miles and miles. By training your body to eliminate the limitations at your hip and ankle, you can learn to run without placing so much strain through your knee. You can run without knee pain.

To understand human body biomechanics requires an understanding of the natural human body asymmetry. It would take a dozen more blogs to fully explain the complexities of the human body, but for the purpose of this blog, what you need to know is the left and right sides of our body respond to stress in different ways, creating different biomechanical limitations and movement compensations. The right leg accepts weight well but does not push off. The left leg is the opposite. It does not accept weight but can push off well. However, these different limitations can still lead to the same pain, regardless of the side of the body it is on, but different limitations require different interventions to correct them.

If You Have Right Knee Pain:

You need to learn how to push off your leg more with your right glute max muscle. Without it, you force the quads and adductors to do too much work, which strains the knee, leading to your pain. Use this exercise to strengthen your right glute max:

Being unable to push off the right leg also leads to the right ankle and foot not moving properly. You never fully pronate and utilize your arch during gait, meaning you do not create enough tibial internal rotation. Without that motion, your ankle cannot fully dorsiflex, the knee does not fully translate forward towards the toes and does not properly flex to accept load, thus increasing the strain on the knee. A right ankle exercise needs to mobilize the tibia into internal rotation to allow for more dorsiflexion:

If You Have Left Knee Pain:

You need to learn how to better load and accept weight on your left leg. Your low back and quadriceps are overactive and prevent the knee from properly accepting force, again, placing more strain on the knee. An exercise for the left hip must strengthen your left hamstring and adductors so these muscles bear more of your weight:

If your left leg does not fully accept your weight, your weight does not transfer on to your left heel. You stay over your toes, which forces your calf muscles to be constantly working to hold you up right. This causes your calves to remain tense and tight, limiting your dorsiflexion range of motion. Limited dorsiflexion means your knee cannot properly flex to accept your weight, again leading to increased strain on your knee. To fix your tight left calf, you must learn how to accept weight on your left leg without creating so much tension in the calf muscles. You can do this with the following exercise:

It is important to note that while these are common biomechanical limitations that can lead to knee pain, they are not the only possible cause of knee pain. The human body is incredibly complex, and every person will present a little bit differently. An assessment by a qualified healthcare professional is necessary to determine what the cause of your knee pain is. If you are ready to finally get rid of your knee pain, then come and see us at Human Function & Performance for an assessment. You will learn exactly why your knee hurts, and we will work with you to develop a plan for getting you out of pain and back to your favorite activities. Call us today at (469) 626-7254 or email me at to set up an appointment.


1. Smith, B. E., Selfe, J., Thacker, D., Hendrick, P., Bateman, M., Moffatt, F., Rathleff, M. S., Smith, T. O., & Logan, P. (2018). Incidence and prevalence of patellofemoral pain: A systematic review and meta-analysis. PloS one, 13(1), e0190892.


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