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I am far from a medical professional of any sorts but this particular injury happens to be some what of a hobby of mine (common fencing injury - all that lunging).

So if I may add my bit?

As you rightly suggested 'Runners Knee' can be caused by a weakening of the inside knee muscle causing the outside knee muscle to be too strong. This causes the outside of the knee to tilt downwards. Which as you said can be remedied by specific quad strengthening.

However another possibility always needs to be looked at and is often overlooked by Ortho specialists, and better diagnosed by a good chiropractor or sports physio.

It’s not a weak inside knee, but a too strong outside knee.

Runners knee can also be caused by too much bad technique running (Fencing Lunging) with not enough stretching causing the ITB to wind up as tight as steel wire.
Basically pulling the knee over to the outside.

Common Symptom:
Distal part of ITB sticking out and lateral part of calf is flat instead of rounded.

Remedy:
A lot of painful deep muscle massage and stretching of the whole ITB.

My understanding is that leaving this untreated for any length of time can cause the weakening of the inside knee muscle, hence the common misdiagnosis.

Bit of an evil cycle isn't it.

Hope this helps someone.

Moral:
Bad knee
=
Orthopaedic and Xrays
+
GOOD Chiro or physio as well

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