………….if you are squatting (barbell, weights), and the right leg (on a right-hand dominant person) always wants to medially collapse, but the TFL/ITB are not weak, what would you look at? This seems to be so common, happens to me and also the guy I train with. As the weight goes up, I actually shift my weight over to the left drastically if I don’t control it, and there is a definite medial-collapse moment………………………My left works so hard that I end up with iliopsoas cramping, which will come on intermittantly with pain and L LE collapse. Squats and deadlifts (bent leg) can cause this as they get heavier than say 115 lb. Ulg, such a light-weight.
So no TFL weakness, nor hamstring on R LE, Quads stronger L > R, but both 5/5 isometrically, adductors equal 4+/5, hip extensors STRONG, 5/5.
IF you have time, could you tell me what else to consider?
This can be just about anywhere in the chain leading to the medial collapse.
You can start by considering the ankle particularly since this is an issue when you are knee-dominant. If you are running out of dorsiflexion, instead of pitching forward off your heels, you are going into pronation and taking the knee with it. This is just one possibility.
If you are able to get down into a squat, it is not likely a hip mobility issue, but a rotary stability issue can leave one hip able to stabilize, and the other not. It can be a crossed-pattern or same side.
Lastly, the t-spine can lead to this particularly if the bar is on your back in the squat. If you have a shoulder mobility asymmetry, this can be the source.
The objective measures are pretty much meaningless. Look for the biomechanics first and then clean up the motor control.