Almost everything that controls your knee comes from the hip above it or the foot below it. When knee pain keeps returning, the cause is often somewhere else, sometimes even in the other leg.
Start here
Why your knee pain might not actually be a knee problem
How your hip and foot load the knee, what the research does and doesn't show, and a one-repetition test that shows which side of your body is really doing the work.
A self-test for the thigh bone shape that changes how much twisting stress reaches your knee, and what to do for each shape.
Test
If your knee keeps coming back to the same pain, 7 Days to Better Knees walks you through testing the hip, the foot, and the compensation pattern at home, step by step.