MSK Rehabilitation, Patient Guide

Runner's knee: what it is, what helps and when to see a physio

Written by Elliot Stubbs, BSc (Hons) Physiotherapy, 13 years in MSK practice. Updated 14 October 2026.

Runner's knee (patellofemoral pain) is an ache around or behind the kneecap, usually brought on by running, stairs, squatting or sitting with your knees bent for a while. It's very common, it rarely means anything is damaged, and most people improve with a spell of adjusted training and steady strength work for the thigh and hip rather than complete rest.

What is runner's knee?

Your kneecap sits in a shallow groove at the bottom of your thigh bone. As you bend and straighten your knee under load, it glides along that groove, and the joint takes a lot of force, especially going downhill, down stairs or into a deep squat.

The medical name, patellofemoral pain, simply means pain from where the kneecap meets the thigh bone. It isn't a tear or a break. It's usually the knee being asked to do more than it's currently ready for, and that capacity can be built back up.

Despite the name, footballers, cyclists, gym-goers and teenagers get it too.

What causes runner's knee?

It's usually a combination of a few of these:

A jump in training. More miles, hills or speed, added faster than the knee can adapt. This is the most common pattern.
Strength that hasn't kept up. Weaker quadriceps (the big muscles at the front of the thigh) or hip muscles give the knee less support with each stride.
How you move. A knee that drifts inwards when you land or squat can change how load passes through the front of the knee.
Changes in surface or kit. More downhill trail running, lots of steps, or a sudden switch in shoes.

What does runner's knee feel like?

Typically:

A dull ache around, behind or just below the kneecap, sometimes hard to point to with one finger
Pain going down stairs or hills more than going up
Pain when squatting, kneeling or getting up from a low chair
An ache after sitting for a long time with your knees bent

It often starts after runs, then creeps earlier into them, and eventually into everyday life if nothing changes.

Is it runner's knee, or pain on the outside of the knee?

Runner's knee sits at the front of the knee, around the kneecap. Pain on the outside of the knee in runners is often a different problem, usually linked to the iliotibial band (the IT band, a thick strip of tissue running down the outside of the thigh). That pain sits on the outer edge of the knee and often comes on at a predictable point in a run, easing when you stop.

The two can overlap, but they're managed a little differently, so an assessment is worth having if you're not sure which you've got.

Simple self-checks you can do safely

These won't diagnose you, but they show how your knee is coping. Stop if anything causes sharp pain.

Step-down test. On the bottom stair, slowly lower your other foot to the floor. Does it bring on your pain, or does the knee drift inwards?
Single-leg squat in a mirror. Holding something for balance, do a small, slow squat on one leg and compare sides.
The sitting test. Does your knee ache after sitting with it bent for a while, then ease when you walk around?
The next-day check. How does the knee feel the morning after a run? This is often the most useful guide of all.

What can I do about runner's knee now?

You usually don't need to stop everything. The aim is to reduce load enough for the knee to settle while keeping it working.

Adjust, don't abandon. Cut back distance or frequency and swap hills and speed work for flat, easy running.
Use a simple pain guide. Mild discomfort during a run that settles quickly, and isn't worse the next morning, is generally acceptable. Pain that builds, changes how you run, or lingers into the next day means you've done too much for now.
Keep fit in other ways. Swimming, or cycling if comfortable.
Start some gentle strength work. Wall sits at a comfortable depth, bridges and side-lying leg raises are a reasonable start, provided they don't increase your pain.
Break up long sits by straightening your leg or standing up regularly.

Rest alone tends to let the pain fade, only for it to return with normal training, because the knee hasn't got any stronger.

How does physiotherapy help runner's knee?

An assessment confirms what's going on, rules out other causes of knee pain and finds what's driving your case: training load, strength, movement, or a mix. Treatment usually involves:

Load management. A clear plan for what running you can do now, and how to build back up.
Progressive strength work. The backbone of treatment. Quads, hip and calf strength are built steadily in the gym, progressing to split squats, step-ups and single-leg work as the knee tolerates more.
Movement and running technique. Small changes, such as a slightly shorter stride, can ease load on the front of the knee for some runners.
Manual therapy and taping. These can offer short-term relief so you can train more comfortably, alongside exercise rather than instead of it.
A graded return to running. Building pace, distance and hills back in one at a time.

Sessions here take place in a fully equipped gym with 1:1 guided rehab, so strength work is supervised rather than handed out on a sheet. Our guide to returning to running after injury covers the return-to-run stage in more detail.

How long does runner's knee take to get better?

It varies. Some people improve within a few weeks of adjusting training, while a full return to normal running commonly takes a few months of consistent strength work, and longer-standing cases often take longer. It can return if training jumps too quickly, so keeping some strength work going afterwards is worthwhile.

When to see a GP or get urgent help

Get urgent medical help (call 111, or go to A&E) if: your knee is hot, red and swollen, especially if you feel unwell or have a temperature; you can't put weight on it after an injury; it swelled up quickly after a twist or fall; or it's locked and won't straighten. Call 999 if you have calf pain or swelling alongside chest pain or breathlessness.

See your GP if knee pain comes with unexplained weight loss or wakes you at night regardless of position, or if a child or teenager has knee pain with a limp or hip pain, as hip problems can be felt in the knee. Pain that doesn't fit the pattern described here, or swelling that keeps returning, is also worth getting checked. In the uncommon cases where they're relevant, a GP or specialist can discuss other options such as injections or surgery.

Physio for runners in Wymondham and Norwich

If you're in Wymondham, Norwich or South Norfolk, whether you're a parkrun regular, a club runner or just getting back into it, Elliot sees runners at Suggs Gym on Tuesday evenings. No GP referral is needed, and you can see the assessment and follow-up prices before you book an assessment.

Frequently asked questions

Can I still run with runner's knee?

Often, yes, with some changes. Reducing distance, avoiding hills and speed work, and keeping pain mild and short-lived is usually fine. If pain builds during a run, changes how you run, or is worse the next morning, cut back further and get it assessed.

Should I wear a knee support or strap for runner's knee?

A support or tape can make running more comfortable for some people in the short term, but it doesn't build strength. It's best used alongside a strength and load plan, not instead of one.

Do I need a scan for runner's knee?

Not usually. Runner's knee can normally be assessed clinically by a physiotherapist without imaging. A scan is only worth considering if something in your history or assessment suggests another problem that would change the treatment plan.

Is runner's knee the same as IT band pain?

No. Runner's knee is pain around or behind the kneecap at the front of the knee. IT band pain sits on the outside of the knee and often comes on at a predictable point during a run. They can overlap, and an assessment helps tell them apart.

Do I need a GP referral to see a physio for runner's knee?

No. You can book a physiotherapy assessment directly without seeing your GP first. See the guide on self-referral for physiotherapy for more detail.

This guide is general information written by a physiotherapist, not a substitute for individual assessment. If you're unsure about any of the warning signs above, seek medical advice rather than waiting for an appointment.