Knee pain mid-run is one of the most common reasons runners stop running. It’s also one of the most fixable, but only if you know what you’re dealing with. The knee takes the brunt of every footstrike, so when something further up or down the leg isn’t pulling its weight, the knee is where you tend to feel it first.
Here’s a guide to the most common causes of knee pain in runners, how to spot what’s actually going on, and what to do about it.
A quick word on the knee
Your knee is a hinge joint where the thigh bone (femur), shin bone (tibia) and kneecap (patella) all meet. Around them you’ve got ligaments holding bones together, tendons connecting muscles to bones, two crescent-shaped cartilage pads (menisci) that absorb shock, and bursae (small fluid-filled sacs that reduce friction).
That’s a lot of structures squeezed into a small space. Pain in the knee can come from any of them, which is why “my knee hurts when I run” rarely has a one-size-fits-all answer.
The most likely culprit: runner's knee
When runners describe knee pain, the most common diagnosis we end up making at our Tunbridge Wells clinic is patellofemoral pain syndrome, better known as runner’s knee. It’s an irritation of the joint between the kneecap and the thigh bone, and it accounts for a big chunk of the knee complaints we see.
What runner's knee feels like
The typical picture:
- A dull ache around or behind the kneecap, not deep inside the joint
- Pain that gets worse going downhill or down stairs
- Pain after sitting for a long time with the knee bent (the “cinema seat” sign)
- Sometimes a grinding or clicking sensation when you bend the knee
- Pain that’s fine at the start of a run, then builds, then lingers afterwards
It usually doesn’t lock, give way, or swell dramatically. If yours does any of those things, get it looked at properly because it’s likely something else.
How to test for it
A few simple at-home tests can point you in the right direction:
- The single leg squat. Stand on the painful leg and slowly squat down a quarter of the way. If pain shows up and your knee tracks inward as you go down, runner’s knee is high on the list.
- The step down. Stand on a low step on the painful leg and slowly lower the other foot toward the floor. Pain at the front of the knee, especially through the deepest part of the movement, is a giveaway.
- Press around the kneecap. Tenderness when you press on the edges of the kneecap, or pain when you press the kneecap down toward the joint, both point to PFPS.
None of these are diagnostic on their own. They’re useful pointers rather than answers.
What else could it be?
Plenty of other things cause knee pain in runners, and a few are commonly mistaken for runner’s knee.
Iliotibial (IT) band syndrome causes pain on the outer side of the knee, often felt as a sharp pain that kicks in at a fairly predictable point in your run and stops you in your tracks. The IT band is a thick strip of connective tissue running from the hip down to just below the knee, and when it gets irritated where it crosses the outside of the joint, it makes itself known.
Patellar tendinopathy (jumper’s knee) is pain in the tendon just below the kneecap. It’s most noticeable when you press on the tendon and during jumping or sprinting. Worse on hills and on hard impacts. We treat this regularly with a combination of shockwave therapy and progressive loading, as the research on tendinopathy strongly favours that approach.
Meniscal irritation tends to cause pain deeper inside the knee, sometimes with a feeling of catching or clicking. It often follows a twist or sudden movement, although degenerative meniscal issues can creep up gradually with no obvious incident.
Knee bursitis comes from inflammation of one of the small fluid-filled sacs around the joint. The first signs are usually localised swelling (often a visible soft bump), warmth over the affected area, and pain that’s worse when you kneel on it or apply pressure directly. Prepatellar bursitis sits right at the front of the kneecap. Pes anserine bursitis sits on the inner side of the knee, about two inches below the joint line, and is one of the more common ones in runners.
Osteoarthritis mostly turns up in older runners. It causes deep, aching pain that’s worse with activity and better with rest. Grinding sensations and morning stiffness lasting more than half an hour are common features.
The treatment plan for each of these is different, which is why a proper assessment matters if your knee pain isn’t shifting.
Will it heal on its own?
Runner’s knee can settle on its own if you reduce the load that’s causing it. The key word is reduce, not “carry on running and hope”. For most cases, four to six weeks of modified activity, combined with the right strength work, sees significant improvement.
Without addressing the underlying causes, though, the issue tends to come straight back the moment you load it up again. That’s the bit most people miss. Rest takes the pain down. It doesn’t fix the reason the knee got irritated in the first place.
How to actually fix it
The treatment we use with runners depends on what we find on assessment, but most plans include some version of the following:
Reduce the irritating activity for a couple of weeks. That doesn’t mean lying on the sofa. Cross-train with something that doesn’t load the knee in the same way (swimming, cycling, elliptical work).
Strengthen the quads, glutes and hips. Single leg work is your friend here. Step-ups, single leg deadlifts, side-lying clamshells, hip abductor work. The research is clear that hip strengthening is one of the most effective treatments for runner’s knee. Our personal training team builds these programs specifically for runners coming back from injury.
Ice and over-the-counter anti-inflammatories can help in the early stages, but they aren’t the treatment in themselves.
Hands-on osteopathy can settle the soft tissues around the joint, restore mobility in the hip and ankle, and free up restrictions further up the chain that may be contributing. A regular sports massage alongside treatment can also help keep things moving while you rehab.
Look at your running form. Overstriding, a low cadence and excessive hip drop are all common contributors. Bumping your cadence up by 5 to 10 percent often takes a noticeable amount of load off the knee.
Footwear. Worn-out shoes, or shoes that don’t suit your foot mechanics, can be the missing piece. If you can’t remember the last time you replaced your trainers, that’s probably your answer.
When to come in
A few signs you don’t want to wait on:
- Pain that doesn’t improve after two to three weeks of rest and modified training
- Locking, catching or giving way of the knee
- Significant swelling
- Pain at night or when you’re not moving
- Any history of a twist or impact injury that preceded the pain
Any of those, and a proper assessment is the next step. We use a combination of hands-on treatment, shockwave therapy where appropriate, and structured rehab to get runners back to running. The point isn’t just to make the pain stop. It’s to fix what caused it, so you’re not back here in six months.
Book in
If your knee is the thing standing between you and your next run, book in for an assessment at our Tunbridge Wells clinic. 95% of new patients are seen within a week, and most runners we treat are back to running, properly, within a handful of sessions.
If you’d rather chat through what’s going on first, we offer a free 15-minute consultation with no obligation. Call 01892 249095 or book online.
