What are the signs of patellofemoral pain syndrome (PFPS), also known as runner's knee?

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From the Guidelines

Runner's knee, or patellofemoral pain syndrome, is characterized by gradual onset diffuse retropatellar and/or peripatellar pain during activities such as squatting, stair ambulation, and running, as reported in a 2024 study published in the British Journal of Sports Medicine 1. The signs of runner's knee include:

  • A dull, aching pain at the front of the knee
  • Swelling
  • Popping or grinding sensations when bending the knee
  • Pain that increases with activity and improves with rest
  • Instability or a feeling that the knee might give way
  • Pain that develops gradually rather than suddenly and may affect one or both knees According to the 2024 study, people with patellofemoral pain are six times more likely to be anxious or depressed, and are on average less physically active, and have poorer health-related quality of life than their asymptomatic peers 1. The pain often worsens with activities like running, squatting, climbing stairs, or sitting with bent knees for extended periods, and may be particularly bad when going downhill or downstairs. Recognizing these symptoms early allows for prompt treatment, which typically includes rest, ice, compression, elevation, and appropriate strengthening exercises for the quadriceps and hip muscles. It is essential to note that patellofemoral pain is thought to be a precursor to patellofemoral osteoarthritis, making a greater understanding of optimal management essential, as highlighted in the 2024 study published in the British Journal of Sports Medicine 1.

From the Research

Signs of Runner's Knee

The signs of runner's knee, also known as patellofemoral pain syndrome (PFPS), include:

  • Pain behind or around the patella (kneecap) 2, 3, 4, 5, 6
  • Pain that worsens with activities that involve knee flexion, such as running, jumping, or descending stairs 4, 5, 6
  • Pain that worsens with prolonged sitting 5, 6
  • Pain with squatting 5
  • Limited patellar mobility or a hypermobile patella 4

Common Characteristics

Common characteristics of patellofemoral pain syndrome include:

  • Insidious onset of poorly defined pain, localized to the anterior retropatellar and/or peripatellar region of the knee 6
  • Pain that can restrict participation in physical activity, sports, and work 6
  • Symptoms that can recur and persist for years 6

Diagnostic Findings

Diagnostic findings for patellofemoral pain syndrome may include:

  • Pain with squatting 5
  • Limited patellar mobility or a hypermobile patella 4
  • Abnormal gait, posture, or footwear 5

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Patellofemoral pain.

British journal of sports medicine, 2016

Research

A review of the management of patellofemoral pain syndrome.

The Physician and sportsmedicine, 2013

Research

Management of patellofemoral pain syndrome.

American family physician, 2007

Research

Patellofemoral Pain Syndrome.

American family physician, 2019

Research

Patellofemoral Pain.

The Journal of orthopaedic and sports physical therapy, 2019

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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