Runner’s knee — the dull, aching pain around or behind the kneecap that flares on hills, stairs, and long runs — is the single most common knee complaint we see. There’s also a lot of dated advice still floating around about how to fix it. Two recent systematic reviews give a much clearer, evidence-backed answer, and it comes down to strengthening the right things, not just resting and hoping.

The most common knee problem in runners

Patellofemoral pain (PFP) — the clinical name for runner’s knee — is consistently identified as the single most common overuse injury in runners. Across studies of running-related injuries, it accounts for roughly 16.7% of all reported knee pain prevalence and around 6.3% of new injury incidence, putting it ahead of most other running complaints. In the general population its annual prevalence sits around 22.7%, rising to 28.9% in adolescents, with young, active women particularly affected.

In other words: if your knee aches after a run, you’re in very large company.

What the evidence says actually works

A 2025 systematic review and meta-analysis in BMC Sports Science, Medicine and Rehabilitation pooled 12 randomised controlled trials comparing strengthening exercise against other conservative treatments — things like taping, orthotics, re-education and patellar mobilisation. Strengthening won. At 4–6 weeks, patients doing strengthening exercise reported an average pain reduction of 1.44 points greater than the comparison group (on a 0–10 scale), and the benefit was still present at 8–12 weeks. Women saw the largest effect — nearly 3 points greater reduction than comparison treatments.

The certainty of evidence was rated low-to-very-low, mostly because pain is self-reported and these trials can’t be blinded — but the direction and consistency of the finding, across 12 separate trials and over 600 patients, is hard to ignore.

Hip vs knee: where the research says to focus

The more specific — and more useful — question is which muscles to strengthen. A 2025 meta-analysis in Musculoskeletal Care compared combined hip-and-knee strengthening against knee strengthening alone across six RCTs and 241 patients (96% women). Combined hip-and-knee work significantly outperformed knee-only strengthening for both pain (a large effect) and function, with no meaningful difference in raw muscle strength gained between the two groups — meaning the benefit isn’t just about getting stronger, it’s about training the hip alongside the knee.

This tracks with earlier work: a well-known 2018 review in the Journal of Orthopaedic & Sports Physical Therapy reached the same conclusion — hip and knee strengthening together beats knee strengthening alone for both pain and activity levels. If your rehab has only ever involved quad sets and straight-leg raises, this is the evidence for why that’s an incomplete answer. Hip abductor and external rotator work (think clamshells, side-planks, single-leg bridges, lateral band walks) deserves at least equal billing.

What this means for you

If you’re managing runner’s knee, the evidence points toward a structured strengthening programme that targets the hip as well as the knee, given time to work — most trials measured benefit from 4 to 12 weeks in, not overnight. It also suggests patience is reasonable: this isn’t an injury where rest alone fixes the underlying issue, and it isn’t one where you need to chase a single “magic” exercise either.

If you’re not sure whether what you’re feeling is patellofemoral pain or something else, run it through our Symptom Checker first. Patellofemoral Pain Syndrome is one of the built-in pathways in our Recovery Planner, with a staged return-to-running plan based on published rehab protocols, and the Capacity Tracker is there to make sure your training load doesn’t outpace what your knee is ready for while you build that hip and knee strength back up.

Sources: Ruisi R, Contri A, Peccerillo V, et al. “Conservative treatment of patellofemoral pain: effectiveness of strength exercises compared to other treatments.” BMC Sports Science, Medicine and Rehabilitation. 2025;17:303. Halabi MH, Alturkistani BA, Abuhadi RH, et al. “The Efficacy of Hip and Knee Muscles Strengthening Versus Knee Muscle Strengthening Alone in Managing Patellofemoral Pain Syndrome.” Musculoskeletal Care. 2025;23(1):e70059. Nascimento LR, Teixeira-Salmela LF, Souza RB, Resende RA. “Hip and knee strengthening is more effective than knee strengthening alone for reducing pain and improving activity in individuals with patellofemoral pain.” JOSPT. 2018;48:19-31.