OK sounds like the pelvis is out of place, perhaps drive a little by the Lx due to no assymmetry in sitting or lying..but this might not be quite accurate. Now you should look for trendelenbergs sign and stork tests on both legs, and look for any in flare or ourflare of the pelvic bones. Draw a midline down from the belly button (naval) and eyeball the distance of the ASIS's from this line. Then give some more feedback. I will try to find some text for these tests that I can copy and paste.

For now though get into releaseing his psoas, illiacus, and piriformis to give the pelvis an opportunity to move. Hold/relax and contract/relax techniques through range of the hip for prriformis and psoas might well help here.