Why Your Knees Hurt When You Run — And What To Do About It
After a long Ottawa winter cooped up indoors, there’s nothing quite like lacing up your shoes and hitting the trail again. The weather turns, the paths clear, and thousands of Ottawa residents do exactly the same thing: jump back into running.
And then, a few weeks in, the knee pain starts.
It might be a dull ache just below the kneecap. Maybe a sharp pinch on the outside of your knee after the 3 km mark. Or a stiffness that greets you the morning after a run. Whatever it feels like, it’s one of the most common reasons runners — from beginners to seasoned regulars — end up in our clinics at Bells Corners and Montreal Road this time of year.
The good news: most running-related knee pain is very treatable. And in many cases, you don’t have to stop running entirely to recover.
Let’s break it down.
Why Spring Is Prime Time for Knee Injuries
There’s a pattern we see every April and May. Runners who were largely inactive through January and February suddenly increase their mileage quickly — often too quickly. Their cardiovascular fitness bounces back fast, but their tendons, joints, and supporting muscles haven’t had the same chance to catch up.
The result is overload. The knee takes on more stress than the tissues around it can handle, and that’s when pain shows up.
It doesn’t mean something is seriously wrong. It usually means your body is telling you to slow down and pay attention.
The Most Common Running Knee Injuries
Runner’s Knee (Patellofemoral Pain Syndrome)
This is the most common one we see. Runner’s knee causes pain around or behind the kneecap, and it tends to flare up during running, going down stairs, or after sitting for a long time with knees bent.
It happens when the kneecap isn’t tracking smoothly in its groove — usually because of muscle imbalances in the hips or thighs, or because of a sudden spike in training load.
The pain can range from mildly annoying to sharp and limiting. Either way, it’s worth addressing early.
IT Band Syndrome
The iliotibial (IT) band is a thick band of connective tissue that runs along the outside of your thigh from your hip to just below your knee. When it becomes tight or irritated, it causes a sharp, burning pain on the outer side of the knee — usually appearing at a predictable point during your run, like the 3 or 4 km mark, and then easing off when you stop.
IT band syndrome is particularly common in runners who increased their distance quickly, run on cambered roads, or have hip weakness that affects their stride mechanics.
Patellar Tendinopathy
Sometimes called “jumper’s knee,” this condition affects the tendon that connects your kneecap to your shin. It causes pain at the front of the knee, just below the kneecap, that tends to be worst at the start of a run, eases as you warm up, and then returns afterward.
It develops gradually from repetitive stress on the tendon and is more common in runners who added hills or speed work to their training.
Knee Bursitis
Bursitis involves inflammation of the small fluid-filled sacs (bursae) that cushion the knee joint. It typically causes a more diffuse, achy swelling around the knee rather than the sharp, location-specific pain of IT band syndrome. If your knee looks swollen or feels warm to the touch, bursitis is worth considering.
A physiotherapist can help you distinguish between these quickly — they respond to different treatments, so getting the right diagnosis matters.
Why the Problem Is Often Somewhere Other Than Your Knee
This surprises a lot of people: the knee is frequently not where the problem starts.
Running knee pain is often a downstream symptom of something happening elsewhere in the body. The hip is a common contributor — when the stabilizing muscles around the hip aren’t doing their job, the knee compensates on every stride. But the lower back, ankle, and foot mechanics can play just as significant a role. Reduced ankle mobility, for example, changes how force travels up through the leg on each footfall. A stiff lower back can alter your stride in ways that add cumulative stress to the knee. Even core stability affects how load is managed across the entire lower body.
The knee ends up being where you feel it — but it’s rarely the whole story.
This is one of the key reasons that simply resting and returning to running — without identifying the underlying cause — tends to bring the pain right back. A proper assessment looks at the full picture, not just the painful joint.
What Physiotherapy Does Differently
When you come in with running knee pain, we’re not just looking at your knee.
We assess your running mechanics, hip strength, foot position, and movement patterns to figure out why the knee is being overloaded in the first place. From there, treatment typically includes a combination of:
Manual therapy to reduce pain and restore normal joint and soft tissue movement — getting you comfortable and moving well again sooner.
Targeted strengthening for the hips, glutes, and quadriceps to correct the underlying imbalances that contributed to the problem.
Load management guidance so you know exactly how much running is appropriate during recovery, and how to build back up without re-injuring yourself.
Gait analysis where relevant — small adjustments to stride length, cadence, or foot strike can significantly reduce stress on the knee.
The goal isn’t just to get you pain-free. It’s to get you back running consistently, without the same injury reappearing in three months.
Do You Have to Stop Running Completely?
Not necessarily — and for many people, complete rest is actually counterproductive.
The answer depends on the type of injury, how severe it is, and how your symptoms behave during and after running. Some runners can continue with modified training while they recover. Others need a short break to let irritated tissue calm down before reloading it.
A physiotherapist can give you a clear, honest answer for your specific situation — and a plan that keeps you as active as possible throughout recovery.
Simple Things You Can Do Right Now
While you’re waiting for an assessment, or if your symptoms are mild, these are reasonable starting points:
Reduce your mileage temporarily. Cut back by 20–30% and see how your knee responds. Don’t stop entirely unless the pain is severe — complete rest often isn’t necessary and can slow recovery.
Check your footwear. Running shoes have a lifespan of roughly 500–800 km. Worn-out cushioning changes how force travels through your knee on every stride and is one of the most overlooked contributors to knee pain.
Add a proper warm-up. Five minutes of brisk walking before you run gives your joints and soft tissues time to prepare for the increased load ahead.
When to See a Physiotherapist
See someone sooner rather than later if:
- The pain is sharp, severe, or stopping you mid-run
- Your knee is swollen, warm, or feels unstable
- Symptoms have been present for more than two to three weeks without improvement
- You’ve had this before and it keeps coming back
Knee pain that gets ignored tends to become knee pain that keeps you off the trails for months. Catching it early means a faster, more complete recovery.
At ADM Ottawa Physiotherapy, our registered physiotherapists see running injuries at both our Bells Corners and Montreal Road locations. If your knees are holding you back this spring, book an appointment or give us a call — we’ll help you figure out what’s going on and get you back to running.
Bells Corners: (613) 820-8765
Montreal Road: (613) 749-7461
Please note: The information in this article is intended for general educational purposes only and does not constitute medical advice. Every individual’s situation is different, and the suggestions above may not be appropriate for all injuries or health conditions. If you are experiencing knee pain, please consult a registered physiotherapist or qualified healthcare provider before attempting any self-treatment. ADM Ottawa Physiotherapy accepts no liability for injury or adverse outcomes resulting from information applied without professional assessment.