Understanding Patellofemoral Pain Syndrome and Effective Rehab Strategies for Runners

Pain under the knee cap during running is a common complaint among runners, often signaling a condition known as patellofemoral pain syndrome (PFPS), or more simply, runner’s knee. This issue can disrupt training, cause frustration, and even lead to longer-term problems if not addressed properly. Understanding the causes, symptoms, and rehab strategies for PFPS can help runners manage pain and return to running stronger and healthier.

Runner’s knee pain area highlighted

What Is Patellofemoral Pain Syndrome?

Patellofemoral pain syndrome refers to pain originating from the contact between the knee cap (patella) and the thigh bone (femur). The pain is usually felt under or around the kneecap and often worsens during activities like running, especially downhill, or going up and down stairs. The knee may feel inflamed or tender, and discomfort can persist after running.

This condition is one of the most common injuries among runners, affecting both beginners and experienced athletes. It is not caused by a single factor but rather a combination of training errors, biomechanical issues, and muscle weaknesses.

Common Causes of Runner’s Knee

Training Errors

Increasing running volume or intensity too quickly can overload the tissues around the knee. Downhill running, in particular, places extra stress on the knee joint, which can exceed the tissue’s capacity to handle load. This overload leads to irritation and pain.

Biomechanical Factors

How your body moves while running plays a significant role in PFPS. One common issue is overstriding, where the foot lands too far in front of the body. This increases the force transmitted through the knee, contributing to pain.

Other biomechanical problems include:

• Hip drop during the running gait

• Knee caving inward or rotating inward (valgus collapse)

• Poor femoral control affecting knee alignment

  
  

Muscle Weakness

Weakness in muscles that stabilise the pelvis and control the femur can cause abnormal knee movement. The quadriceps muscles, especially the vastus medialis oblique (VMO), and the lateral hip stabilizers like the gluteus medius are crucial for maintaining proper knee tracking.

Recognising the Symptoms

Runners with PFPS often describe:

• Dull, aching pain under or around the kneecap

• Pain that worsens during running, especially downhill or on stairs

• Knee stiffness or swelling after activity

• A feeling of the knee “giving way” or instability in some cases

  
  

Early recognition of these symptoms is important to prevent worsening of the condition.

The Importance of Early Physiotherapy Assessment

Getting an early assessment from a physiotherapist can make a big difference. A professional evaluation helps:

• Confirm the diagnosis of PFPS

• Identify contributing factors such as muscle weaknesses or gait abnormalities

• Develop a tailored rehab plan to address specific issues

• Prevent the injury from worsening during training blocks

  
  

Physiotherapists use movement analysis and strength testing to pinpoint the root causes of pain and guide runners through safe recovery.

Rehab Strategies for Patellofemoral Pain Syndrome

Rehabilitation focuses on reducing pain, restoring strength, and correcting movement patterns. The key principles include starting pain-free, using a shortened range of motion, and gradually increasing load.

Strengthening Exercises

Here are some classic exercises that target the muscles involved in PFPS rehab:

• Quadriceps Sets

Sit with your leg straight and tighten the muscles on the front of your thigh. Hold for 5 seconds and release. Repeat 10–15 times.

• Straight Leg Raises

Lie on your back with one leg bent and the other straight. Lift the straight leg to the height of the bent knee, hold for 3 seconds, then lower slowly. Perform 3 sets of 10.

• Clamshells

Lie on your side with knees bent. Keeping feet together, lift the top knee while keeping hips stable. This targets the gluteus medius. Do 3 sets of 15 reps on each side.

• Mini Squats

Stand with feet shoulder-width apart and bend knees slightly (about 30 degrees). Keep knees aligned over toes and avoid inward collapse. Hold for a few seconds and return to standing. Perform 3 sets of 10.

• Step-Ups

Use a low step and step up with one foot, then step down slowly. Focus on controlled movement and knee alignment. Do 3 sets of 10 reps per leg.

Gait and Biomechanics Correction

Working with a physiotherapist or running coach to adjust running form can reduce knee stress. Key points include:

• Avoid overstriding by landing the foot closer to the body’s center of mass

• Strengthen hip muscles to prevent knee collapse inward

• Improve pelvic stability to reduce hip drop

  
  

Gradual Return to Running

Rehab should include a gradual return to running, starting with low intensity and short duration. Pain should guide progression—if pain increases, reduce load and focus on strengthening.

Tips to Prevent Patellofemoral Pain Syndrome

• Increase running volume and intensity gradually, no more than 10% per week

• Include strength training for hips and quadriceps in your routine

• Avoid excessive downhill running during training blocks

• Pay attention to running form and seek professional advice if pain develops

• Use appropriate footwear that supports your running style

  
  

When to Seek Professional Help

If knee pain persists beyond a few weeks, worsens, or limits your ability to run, consult a physiotherapist. Early intervention can prevent chronic problems and help you return to running safely.