Updated May 2026. Written by the Upwell Health Collective clinical team. Clinically reviewed May 2026. Next review due November 2026. For educational purposes only.
Runner’s knee. The very name points you in the wrong direction. It makes you think about the knee. It makes you think about the kneecap. It makes you think about the joint where you feel the pain. And because that’s where the pain is, it seems logical that’s where the problem is.
It almost never is.
Patellofemoral pain syndrome (PFPS) — the clinical term for what most runners call runner’s knee — is one of the most common musculoskeletal conditions in Australia, accounting for 25 to 40% of all knee disorders presenting to physiotherapy and sports medicine clinics. It affects runners, cyclists, triathletes, hikers, gym athletes, and people who simply sit at a desk for long periods. It is characterised by pain around or behind the kneecap during activities that load the patellofemoral joint: running, squatting, stairs, prolonged sitting, and landing from height.
And it is, in the vast majority of cases, a hip problem wearing a knee costume.
This article explains what PFPS actually is, why your hip is almost certainly the culprit, what the current evidence says about treatment, and what the most common mistakes runners make that keep them in pain for months longer than they need to be.
The patellofemoral joint is the joint between your kneecap (patella) and the groove at the bottom of your thigh bone (femur) through which it glides as your knee bends and straightens. In normal function, the kneecap tracks smoothly through this groove, distributing force evenly across the joint surface during loading activities.
PFPS occurs when this tracking goes wrong. The kneecap is pulled laterally — toward the outside of the knee — by a combination of muscle imbalances, biomechanical patterns, and loading demands that exceed the joint’s capacity to manage. This lateral pull creates uneven pressure on the cartilage behind the kneecap, producing the characteristic anterior knee pain that worsens with loading and, in many cases, becomes excruciating on stairs or after prolonged sitting.
What causes the lateral pull? This is the question that changed how clinicians think about PFPS. For years, the answer focused on the VMO (vastus medialis oblique) — the teardrop-shaped inner quad muscle that was theorised to provide the medial pull that balanced the kneecap. Treatment targeted the VMO. Countless physiotherapy programmes consisted of leg extensions and VMO-specific exercises designed to “pull the kneecap back into alignment.”
The evidence has systematically dismantled this model. The problem is not primarily at the knee. It is above it.
The femur — the thigh bone — sits between the hip and the knee. When the hip abductors and external rotators are weak, the femur drops and internally rotates during single-leg loading activities like running. This movement drives the knee inward, creating valgus (knee-in) alignment that concentrates lateral force on the kneecap — from above, not from the knee itself.
The evidence for this mechanism is now overwhelming:
The clinical picture: if your VMO looks fine, your quad strength is decent, but your hip abductors and external rotators are weak and your gluteus medius fires late and incompletely during single-leg loading — your kneecap is going to be pulled laterally with every step of every run. This is not a kneecap problem. This is a hip problem.
Hip weakness doesn’t just affect the joint directly. It changes how you run.
A runner with weak hip abductors and external rotators typically shows a characteristic pattern: ipsilateral pelvic drop (the pelvis drops on the side of the stance leg), femoral internal rotation, knee valgus collapse, and foot pronation. This is the Trendelenburg-like pattern that drives PFPS — and it is visible on video analysis, quantifiable on force plate assessment, and directly addressable through targeted hip strengthening and movement retraining.
Cadence modification has also emerged as a clinically useful intervention for PFPS in runners. A 2024-2025 systematic review on running cadence modification found that moderate increases in cadence (typically 5 to 10%) consistently reduced patellofemoral joint stress by shortening stride length, reducing vertical ground reaction forces, and improving lower limb alignment. In practical terms: a 5% increase in cadence — going from 160 to 168 steps per minute, for example — meaningfully changes the loading pattern of the patellofemoral joint with every stride. For a runner covering 40 kilometres per week, that is a significant cumulative reduction in joint stress without any change to distance or speed.
The foot also plays a role. Excessive pronation at the foot and ankle increases tibial internal rotation, which is transmitted up the kinetic chain to the femur and the patellofemoral joint. Foot orthoses — custom or off-the-shelf — are supported by evidence as an adjunct intervention for PFPS, particularly in runners with measurable foot pronation and associated biomechanical patterns. The JOSPT Plantar Fasciitis CPG notes that orthoses combined with other interventions outperform passive interventions alone.
PFPS is fundamentally a load tolerance problem. The patellofemoral joint is tolerating less load than is being demanded of it. The solution is either to reduce the demand, increase the tolerance, or both.
Most runners try to reduce the demand by stopping running entirely. Then they rest for two weeks, feel better, go back to running the same mileage at the same pace with the same mechanics, and find that the pain returns within days. This is the most common PFPS management mistake, and it happens because rest addresses symptoms without addressing capacity.
The evidence-based approach is graduated load management:
The goal is not to protect the joint by avoiding load. It is to build the system that distributes load better. That system is primarily the hip complex.
PFPS is described in the research literature as a “black hole” in orthopaedic medicine: a condition without a single definitive cause or treatment, with a significant proportion of patients developing persistent or recurrent symptoms. A systematic review found that approximately one-third of athletes with PFPS were unable to return to sport within 6 months.
The runners who end up in this chronic trap almost invariably share common features:
The good news: chronic PFPS is addressable. Even in runners who have been dealing with it for months or years, a comprehensive programme targeting hip strength, running mechanics, cadence optimisation, and graduated load management consistently produces meaningful improvements. It is not too late — but the programme needs to target the actual problem, not just the site of the symptoms.
A 2025 systematic review and meta-analysis (BMC Sports Science, Medicine and Rehabilitation) on strength exercise treatment for PFPS found a significant reduction in pain at 4 to 6 weeks (mean difference -1.44; CI -2.20 to -0.67) and at 8 to 12 weeks (mean difference -0.8; CI -1.23 to -0.37) in favour of exercise intervention. The evidence clearly supports exercise as the cornerstone of PFPS treatment.
The current evidence hierarchy for PFPS treatment:
Strong evidence:
Moderate evidence:
Limited or mixed evidence:
What doesn’t work:
When a runner presents to Upwell with PFPS, the assessment is comprehensive and built around the hip-first model:
Most runners with PFPS who engage fully with this programme are back running without pain within 8 to 12 weeks. The ones who struggle are almost always the ones who wanted to keep running the same mileage without modifying mechanics or building the hip strength that would let them do so safely.
If runner’s knee is limiting your training — or if you’ve had it before and it keeps coming back — contact our team or book a running assessment. One comprehensive session will tell you exactly what’s driving it and what needs to change.
PFPS is generally a gradual-onset, activity-related condition. The following presentations warrant urgent clinical assessment to rule out more serious pathology:
Runner’s knee is a misnomer. The pain is in the knee. The problem is almost always above it.
Weak hip abductors and external rotators allow the femur to drop and internally rotate under load, pulling the kneecap laterally and creating the uneven patellofemoral joint stress that produces PFPS. The solution is not rest, not VMO-isolation exercises, and not passive treatment. It is building the hip complex that distributes load correctly, combined with progressive return to running and mechanics retraining.
PFPS affects 25 to 40% of all knee presentations in sports medicine and physiotherapy. Most cases are eminently treatable with the right programme. The critical step is looking above the knee for the answer.
This article is for educational purposes only. It does not substitute for individual clinical assessment. Information last reviewed May 2026.