Patellofemoral pain is felt behind the kneecap and often causes knee pain when going down stairs.
Also known as Patellofemoral Pain Syndrome or PFPS, it may be felt centrally at the front of the knee or on either side of the kneecap.
The secret to fixing this injury is understanding what causes the pain, the reason why it started hurting in your case and how to correct it.
What causes patellofemoral pain?
The injury arises when the pressures inside the joint, pulling the patella into the groove on the femur/(thigh bone), are not well aligned. This causes excessive force to concentrate on one part of the joint cartilage, causing pain.
Patellofemoral pain syndrome is NOT caused by “patella tracking”. Patella maltracking is the notion that the patella is tracking/moving on the wrong path.
This could occur in conjunction with moderate to severe congenital deformities of the shape of the joint surfaces, which is only present in a very small portion of cases.
It’s also not the result of VMO weakness. The VMO is a small portion of one of the quads muscles on the inside aspect of the knee (labelled as “Vastus Medialis” on the image below).
It is such a small contributor to patella forces that it just couldn’t generate enough sideways force on the kneecap to have a major impact on its function.
PFPS typically causes most knee pain when going down stairs or down hills, whether walking or running. But it can also be felt during a pivoting movement, such as a side step, or any single leg loading.
Patellofemoral pain doesn’t have a structural cause. That is, there’s no damage involved.
It can be associated with knee swelling but this is less common. When swelling occurs, it’s a cartilage irritation that causes symptoms but without defects in the cartilage surface.
This isn’t to be confused with patellofemoral OA or osteochondral defects, which both have a structural cause with damage to the cartilage layer in the joint.
So is it “Runner’s Knee” or “PFPS”?
Patellofemoral pain has been given many names over the years. They all describe the same issue, so you can pretty much take your pick.
“Patellofemoral pain” is also called “Patellofemoral Pain Syndrome” (PFPS for short) or “Patellofemoral Syndrome” (PFS).
You may also hear it called “Runner’s knee”, although this is obviously a generic term and not used medically.
I’m personally not a fan of the “syndrome” tag because it hints at an element of uncertainty. That may have applied 30 years ago but we’ve got a much better understanding of it now.
Why did my knee start hurting?
That’s really the crux of it – why did your knee start hurting now? Your training is consistent, nothing seemed different. So why now?!?
Patellofemoral pain will start when there is an alteration in forces that causes an overload on part of the joint surface.
That overload can come from normal activity with a poorly aligned leg, causing an overload of part of the joint.
Or it can come from excessive loading overall (compared to normal activities for the individual), causing an overload of the whole joint surface.
Overload due to poor alignment
Alignment of the knee doesn’t just refer to the knee falling inwards (known as ‘valgus’ movement).
The knee will twist due to foot pronation. This movement generates eversion, or outwards tilt, of the ankle which in turn causes the tibia to rotate.
Rotation at the knee can also occur with a loss of hip rotation control when the hip, and knee, rotate inwards.
These alignment issues can be made worse by poor footwear choices or worn shoes, fatigued muscles around the hip and lower leg or sloping ground.
If you think poor footwear is a contributor, our Physiotherapists have prepared a list of the best running shoes for bad knees for your next upgrade.
Patellofemoral pain syndrome treatment
Not surprisingly, the fix for PFPS needs to match the cause. Otherwise it won’t be successful and the injury won’t respond.
The good news is that correcting the underlying alignment issue should give immediate relief of most of your pain. So it’s an easy task to trial and test different treatment options.
Testing PFPS and how it responds to different loading patterns
- Start by performing a few single leg squats to 1/4 depth while barefoot. Rate your pain out of 10 (0 = no pain, 10 = worst pain). This gives you a baseline measure of your pain.
- Re-test the same movement after adding a small support under the arch of your foot. Something about the width and thickness of a mobile phone should work nicely. Rate the change in pain – you’re looking for a reduction of around 2/10 for it to matter.
- Remove the arch support and stand with your hands on your hips. Deliberately raise the hip on the opposite side to your stance leg then perform a single leg squat while maintaining the raised hip. Again, rate your pain.
Finding effective treatment options
After performing these tests, focus on the set up that gave you the most relief.
- If you didn’t improve with points 2 or 3 above
- Reduce the loading through the patellofemoral joint for a few weeks and gradually reload it as pain allows.
- Avoid squats, step ups, lunges and hill running.
- Focus on deadlifts and running on flat ground.
- If you improve with point 2, arch support,
- You can get quick relief from supportive shoes, orthotics or Low Dye for taping.
- Longer term improvement comes from exercises which focus on ankle and foot control.
- When the best response comes from hip hitching,
- Perform an exercise program that improves hip strength and control, such as an Anti Rotation Press (see video below).
- Add in recovery methods for hip muscles to reduce fatigue, such as foam rolling or trigger point ball exercises.
Other approaches which can be helpful in most cases of PFPS include:
- McConnell or PFPS taping (see video below) can be very effective, with over 90% success rate.
- General and strength exercises while minimising symptoms – just don’t move past 30 degrees knee bend (eg. deadlift instead of squat, run on flat ground).
Don’t fall for these myths
PFPS is not related to being bow-legged or knock-kneed – you’ve always had that alignment yet the pain is more recent.
That “grinding” feeling on bending has nothing to do with cartilage damage or the injury.
Patellofemoral pain doesn’t come from “maltracking”. It’s related to increased pressure on certain parts of the joint but the kneecap doesn’t actually move on a different track or path.
The Clam exercise doesn’t work as effectively as a simple single leg squat for muscle activation, muscle loading, improvement in function or symptom reduction.
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