Hi - good advice from DrDamien and the others.

I just wanted to add that the Wikipedia reference-linkSIJ can cause such issues but it is rarely the only reason...it can only move a few mm whereas you need at least 5-10mm to be a noticeable LLD. Trust me, if your SIJ was "out" that much, you would have a hard time walking.

What is more likely to be happening is that there are muscles that are working differently from side to the other. This causes asymmetry and an apparent LLD.

By resetting the pelvis as you describe, it would seem that the problem is in the "apparent LLD" category as the others above correct suggest.

As DrDamien has said above, get everything assessed properly

Cheers!