Patellofemoral Pain Syndrome: What the Evidence Says About Runner's Knee

A dull, aching pain around or behind the kneecap that flares with running, squatting, stairs, or sitting through a long movie — that's the classic presentation of patellofemoral pain syndrome (PFPS), commonly called runner's knee. It's one of the most frequently seen complaints in sports medicine clinics, affecting both competitive runners and people who aren't athletes at all.

What's Going On Behind the Kneecap

PFPS results from abnormal stress on the cartilage and soft tissue where the kneecap (patella) tracks against the thigh bone (femur) during bending and straightening. It's considered a multifactorial condition — contributing factors include weakness in the hip abductors and external rotators, quadriceps weakness, tightness in surrounding tissue, and training errors, rather than any single structural cause.¹ This is part of why two people with seemingly similar knee pain can need fairly different treatment approaches.

Why Strength Training Leads the Evidence

A 2025 systematic review with meta-analysis comparing strengthening exercise against other conservative treatments found that exercise-based approaches — particularly those combining hip and knee strengthening — consistently outperformed passive treatments for reducing pain and improving function.¹ A related 2025 review focused specifically on knee extensor (quadriceps) training found that structured strengthening programs are a core, evidence-supported component of PFPS rehabilitation, though optimal dosing and exercise selection are still being refined.²

Where Bracing, Taping, and Orthotics Fit

Patellar taping, knee bracing, and foot orthotics all appear in PFPS treatment plans, generally as adjuncts that may reduce pain enough to tolerate an active rehab program rather than as treatments that resolve the condition on their own.³ The common thread across current reviews is that passive modalities support the process; they don't replace the loading and strengthening work that actually addresses the underlying mechanics.

The Takeaway

Runner's knee is rarely a sign of structural damage, and it responds well for most people to a consistent hip- and knee-strengthening program over several weeks to months. Pain that doesn't improve with a real trial of structured strengthening, or that's accompanied by swelling, locking, or instability, is worth an in-person evaluation to rule out other causes of anterior knee pain.