Patellofemoral Pain: Why Your Kneecap Hurts and What to Do

What is patellofemoral pain?

The patella (kneecap) sits in a groove at the end of the femur and glides up and down as you bend and straighten your knee. When it doesn't track smoothly in that groove - because of muscle imbalances, biomechanical issues, or overload - the cartilage underneath gets irritated.

The result is a dull, sometimes sharp ache around or behind the kneecap. It's one of the most common running injuries, particularly in women and newer runners.

What it feels like

• Aching around or behind the kneecap during or after running
• Worse on hills, stairs, and squatting
• Stiffness after sitting with knees bent for a long time (the classic "cinema sign")
• Occasional grinding or clicking, though this alone isn't a problem

What causes it

Weak hip abductors and external rotators - when the glutes and hip muscles are weak, the thigh rotates inward during running. This pulls the kneecap out of its groove.

Weak VMO (vastus medialis oblique) - the inner part of the quad muscle helps keep the kneecap tracking medially. When it's underactive, the kneecap drifts laterally.

Tight IT band and lateral structures - pulls the kneecap outward, increasing pressure on the lateral cartilage.

Overpronation - excessive inward roll of the foot causes inward rotation all the way up the chain to the knee.

Training load - too much too soon is the most consistent trigger.

The exercises

1. Clamshell

Lying on your side, knees bent, feet together. Open the top knee like a clamshell. 3 sets of 20. Non-negotiable starting point for hip strengthening.

2. Side-lying hip abduction

Lying on your side, top leg straight. Lift it to 45°, lower slowly. 3 sets of 15. Targets gluteus medius directly.

3. Step-up (controlled)

Step up onto a 20 cm box, control the descent on the affected leg. 3 sets of 12. Functional quad and hip strengthening together.

4. Terminal knee extension with band

Band behind the knee, straighten the last 20° of extension. 3 sets of 15. Activates the VMO specifically.

5. Single-leg squat

Squat to 60° on one leg, watch that the knee tracks over the second toe. If it collapses inward, it's a sign hip work is needed. 3 sets of 10.

Running adjustments

• Reduce downhill running - highest patellofemoral load
• Increase cadence - reduces knee flexion angle at ground contact, which reduces patellofemoral stress
• Check your footwear - motion control or stability shoes can help with overpronation

When it gets better

Most cases improve significantly in 6–8 weeks with consistent hip and quad strengthening. The key is addressing the cause - not just managing the symptoms. Runners who only stretch and foam roll tend to stay stuck.