Knee Pain When Running: What Could it Be?

Runner’s Knee Rehab Resources >>
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Identifying Your Knee Niggle

There are of course numerous different potential causes for knee pain when running. However amongst runners, the two of the most common types of knee pain we see are:

Both of these conditions have a nasty habit of starting off slightly niggly then developing into a full-blown chronic injury if not assessed and rehabilitated appropriately.

This time of year, during spring marathon season, we see a huge number of runners coming to us with one or the other of these knee injuries. It happens every year. Their stories are usually very similar, involving an increase in weekly running milage and long run duration in preparation for a late-spring marathon.

This increased running volume and frequency often exacerbates existing biomechanical flaws in running form, leading to injuries such as these, which had previously been avoided in times of lower running volume and training load.

Of course, it’s not just increased running volume that can pick on technique flaws and movement dysfunctions, to the point of injury. Some runners will find that adding hill running workouts or speed work into the program before they are ready, can also exacerbate muscular imbalances leading to these conditions.

Self-Diagnose Your Knee Pain

Read the following descriptions and note which symptoms and locations seem similar to your pain. This will provide a good guide to the nature of your injury.

Most guides will cite the location of the pain around your knee as being the most obvious differentiating factor between these two injuries. With ITBS more typically presenting as lateral knee pain, and PFPS being more anterior in location, originating from the knee cap area.

However, there are various other factors you can take into consideration in identifying your injury.

It’s really important for me to preface this with saying that an online self-diagnosis is in no way an appropriate substitute for seeking the advice and proper assessment of your injury from an experienced sports injury professional.

If you’re taking your injury seriously enough to have read this far, you should definitely go and see a physiotherapist or similar professional.

That said, Paul Ingraham at has constructed this useful table comparing the symptoms of both patellofemoral pain syndrome (runner’s knee), and ITB syndrome:

Iliotibial Band SyndromePatellofemoral Pain Syndrome
The epicentre of the pain is on the side of the knee. Symptoms may occur nearly anywhere around the entire knee, particularly in severe cases, but the worst spot has to be on the side of the knee.The epicentre of the pain is somewhere under or around the kneecap. As with ITBS, symptoms may occur nearly anywhere, but it will usually be mainly on the front of the knee.
There is a spot on the side of your knee, right around the most sticky-outy bump, that is sensitive to poking pressure, but your kneecap is not particularly sensitive when pushed firmly straight into the knee.It’s not very comfortable pushing your kneecap straight into your knee, but there is no particularly sensitive spot on the side of your knee.
Pain tends to be worse when descending stairs or hills, and is either not painful at all or noticeably less painful when ascending.Pain tends to be worse when ascending stairs or hills, but may be painful both ascending and descending.
Pain first started while going downhill.Pain first started while going uphill.
Both PFPS and ITBS can start over the course of a few hours or a day, but ITBS almost always does. The pain can start relatively quickly.Your pain grew relatively slowly, over months or years.
Doing a deep knee bend does not especially hurt.Doing a deep knee bend definitely hurts.
Pain is not particularly affected by sitting, although it might get worse after sitting for quite a while (longer than an hour).Pain is clearly aggravated by sitting with knees bent. When you get up, it hurts more than it did when you sat down.
You do not have any obvious structural problems in the legs.You are a little knock-kneed, have flat feet, or kneecaps that seem to be kind of at a funny angle.
Symptoms tend to be quite consistent and predictable, with only minimal changes in the intensity of the epicentre over time, and almost no change in the exact location of the hottest spot.PFPS may also have consistent symptoms, in which case you can’t really check either side for this point. However, if you experience seemingly mysterious fluctuations in intensity or location — if you find that the problem is just not very predictable — this is a strong indicator that you have PFPS, not ITBS, so you should check this side.

Original source: The Runner’s Knee Diagnostic Stand-Off

If Your Symptoms Don’t Fit This Pattern

If you have knee pain symptoms that don’t fit into the descriptions above, such as (but not limited to):

  • Locking, instability or giving-way of the knee
  • General swelling of the knee
  • Altered sensation, pins & needles, numbness

It’s likely you have a different knee injury, not falling under the banner of PFPS or ITBS. You should certainly seek a professional opinion.

Knee Rehabilitation Exercises

Anatomically speaking, the knee is stuck in a pretty unfortunate position! It requires good alignment to be able to operate without dysfunction, injury and pain – yet it’s located between two very mobile structures: the hip and ankle/foot.

When working with an injured knee we often find that control at the hip and/or foot and ankle is compromised, disrupting the alignment and loading of the knee as we run.

A specific rehab program is needed to engage and strengthen the right muscle groups to develop neuromuscular control as we learn correct movement patterns, to put the knee in a better position as we run. Here’s a great functional exercises to strengthen muscles around the knee, and work on single leg stability.

Not only do we need to strengthen the correct muscles to look after the knee, and improve control as we move. It’s important to work to remove any muscular imbalances, stretching over active muscles as we strengthen their weaker counterparts.

Runner’s Knee Rehab Resources >>
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Some Runner’s Knee Exercises to Get You Started:

Single Leg Squat

A simple but effective exercise to work on single leg stability…

Active & Static Hip Flexor / Quad Stretch

Tight quads and hip flexors are a common factor in both ITBS and PFPS. Here’s a great stretch…

Hip Thrust

This is great for strengthening those Glutes. Keep your core tight, and squeeze your butt as you come to the top…

I hope this quick guide helps give you an idea of what could be causing your knee pain.

If you have any questions, please feel free to let me know in the comments below…

Read Next >>
Can You Cure Runner’s Knee?
Last updated on March 2nd, 2021.


  1. Mmm I have different pains in my knees and fit both ITB and PFPS but physio!! Physio prescribed lots of glute strength work and stretching.

  2. Interesting you put this on Twitter today… I am suffering from what is probably ITBS right now but it has been quite an acute arrival of the pain! My left knee has always been bad and regularly niggles but my right knee has recently become painful. I have been very slowly introducing change to my programme and was at 9 weeks which has included glute work throughout… The main symptom however which is not listed below is clicking / popping of the knee – both during squats and non-weight bearing movement! I am off to see the physio tomorrow but would be interested if you have come across this symptom with ITBS before or whether it is always due to other damage such as meniscus tear?

  3. Hi James,

    I’m curious. I have been out of running for about 4 weeks with pain that slowly started in the back of my knee then disappeared and moved to the inside (anterior) side of my knee. The pain is not under or around the kneecap but located on the anterior side of the knee. All the symptoms are exact to IB issues but with the location of pain being anterior. I have iced, rested, and foam rolled my legs, but it’s pretty slow going with returning.


  4. OK, the thing I discovered which healed my slipping, knackered knee caps (caused by over running and over-stretching, with not enough weight training). Lie flat on back. Use a small ankle weight, if you can. Without locking the knee, but with a straight leg, raise leg to vertical and lower to floor. Repeat 30 times on each leg. Do this daily. I went from hobbling back to running, although it took a couple of months, and as long as I keep the exercises up, have no further problems.

  5. i wish I could get my back of knee pain diagnosed. It’s round the back of my leg, right behind the knee (Central) and just comes on suddenly stopping me dead running, but I can walk home. When I then get home I can’t bend my knee to walk down stairs and struggle to walk down hill as it feels too swollen behind my leg. Pain goes down into top of calf. I actually think the problem starts at the hip. The sports physio just keeps saying its bio mechanical. And sure enough the next day it’s vanished. No problem walking etc, just starts up when I run again. Grrrrrrr!