If you have a dull ache around or behind your kneecap that is worse on stairs, on hills, and after sitting still for a long time — that is almost certainly what clinicians call patellofemoral pain, and what everyone else calls runner’s knee. It is the most common running injury there is, and there is a real treatment for it. There is also a lot of confident advice about it that the evidence does not support.
How to recognise it
Runner’s knee is pain around or behind the kneecap, rather than sharply on one spot. It typically comes on gradually rather than in a single moment, and it is provoked by loading a bent knee: running downhill, stairs, squatting, and the classic one — sitting with the knee bent for a long stretch, sometimes called the cinema sign.
Pain sharply on the outside of the knee is more likely iliotibial band syndrome. Pain on the bony point below the kneecap is more likely patellar tendinopathy. Swelling, locking, giving way, or an injury with a distinct moment of onset are all reasons to get it looked at rather than self-manage.
What actually works: exercise therapy
A Cochrane review pooled 31 trials covering 1,690 people. Exercise therapy reduced pain in the short term by a mean of 1.46 points on a 0–10 scale (95% CI −2.39 to −0.54), and improved function with a standardised effect of 1.10 (95% CI 0.58 to 1.63). Both confidence intervals include the threshold for what counts as a difference a patient would actually notice.
The single clearest practical finding: hip and knee exercises together beat knee exercises alone (mean difference −2.20, 95% CI −3.80 to −0.60). That result is echoed in the 2018 international consensus statement on patellofemoral pain, which recommends combining the two in preference to knee work on its own.
The honest caveat on that evidence
Cochrane graded the evidence for every one of its seven main outcomes as very low quality, “generally due to serious flaws in design and small numbers of participants”, and stated plainly: “we are very unsure about the estimates.” Eight trials were at high risk of selection bias, and most were at high risk of performance and detection bias because nobody was blinded.
So the accurate sentence is: exercise therapy is the best-supported treatment for runner’s knee, and the evidence supporting it is of very low quality. Both halves are true and the second half is almost always dropped.
The part that will surprise you
The standard explanation for runner’s knee is weak hip muscles letting the knee collapse inwards. Runners with the pain do often test weaker at the hip. But when researchers measure people before anyone gets injured, the story falls apart.
A 2014 systematic review found moderate-to-strong evidence from prospective studies of no association between hip strength and the risk of developing patellofemoral pain, and concluded that reduced hip strength “may be a result of PFP rather than the cause”. A 2019 review of 18 prospective studies covering 4,818 people agreed hip weakness was not a risk factor — and found that in adolescents, greater hip abduction strength was associated with higher risk.
This does not mean stop doing hip work. Hip-focused exercise remains the best-supported treatment. It means the popular causal story — weak glutes caused this — is not established, and you should be sceptical of anyone who diagnoses you from that premise alone.
What the evidence says not to bother with
The 2018 consensus statement, from a panel reviewing the field, is unusually direct:
- Joint mobilisations — of the patella, knee or lower back, in isolation: voted inappropriate.
- Electrophysical agents — ultrasound, TENS and similar: voted inappropriate.
- Taping and bracing, dry needling, manual soft-tissue work, blood-flow-restriction training, gait retraining: all voted uncertain.
A separate 2019 clinical practice guideline goes further on two of these, giving Grade A recommendations against dry needling and against manual therapy used in isolation — meaning there is good evidence they do not work. Note the disagreement: one document says “we don’t know”, the other says “don’t”. Neither says “yes”.
Foot orthoses are the one passive treatment with support, recommended for short-term pain relief. The consensus adds its own caveat: the average pain reduction from prefabricated orthoses “may be considered to lack clinical significance, due to substantial individual variability in response”. And there is no evidence that custom orthoses beat off-the-shelf ones.
A realistic plan
- Do not stop running entirely unless you have to. Reduce volume and remove the provocations — downhills and speedwork first — to a level where pain stays low during and after, and does not linger the next morning.
- Load the hips and the knee, together, and progress it. Not a random circuit. The same movements, getting harder over weeks: split squats, step-downs, hip abduction work, and knee extension through a range that does not provoke pain.
- Give it months, not weeks. Cochrane’s own figure for recovery at 12 months — 88 more people per 1,000 recovered with exercise therapy — had a confidence interval running from 2 fewer to 210 more. The honest reading is that recovery is usually slow and not guaranteed by any single approach.
- See a physiotherapist if it is not improving. Especially if pain is worsening, waking you at night, or you have swelling or instability.
References: van der Heijden RA, et al. Exercise for treating patellofemoral pain syndrome. Cochrane Database Syst Rev, 2015. doi:10.1002/14651858.CD010387.pub2 · Collins NJ, et al. 2018 Consensus statement on exercise therapy and physical interventions for patellofemoral pain. Br J Sports Med, 2018. doi:10.1136/bjsports-2018-099397 · Rathleff MS, et al. Is hip strength a risk factor for patellofemoral pain? Br J Sports Med, 2014. doi:10.1136/bjsports-2013-093305 · Neal BS, et al. Risk factors for patellofemoral pain: a systematic review and meta-analysis. Br J Sports Med, 2019. doi:10.1136/bjsports-2017-098890