[Shaxy]

Morning Karina,
Cold in Stellies?
just logged onto the site after looking up some other stuff and saw your question. Thought I would add something as from what you have written you are so on the right track anyway.
As you know by now the lateral femoral cutaneous nerve (LFCN) arises from the ventral rami of the L2 and L3 nerve roots. This purely sensory nerve is formed just deep to the lateral border of the psoas muscle, then descends in the pelvis over the iliacus muscle deep to the iliacus fascia. Just medial to the ASIS, the nerve exits the pelvis by passing through the deep and superficial bands of the inguinal ligament as they attach to the ASIS. The nerve is also passes the inguinal ligament (where your illiopsoas runs too), but then it takes a vertical course out to the surface of the thigh. When doing lunges you are going to be leaning a little to the ipsi-lateral side "crunching" that area. (check pelvic stabilizers) and also possibly setting off illiopsoas spasms so check for MFTPs at least compare the 2 sides. (I find gentle PNF works well)
Ultimately you should check and mobilize gently L2 and L3 on the right opening up the IVFs. Should this not work then referral for an MRI is necessary for prolapsed disc.
Questions to keep in mind are osteoporosis(bone density scan) and discs especially after long term corticosteroid use and hypoparathyroidism. Unfortunately with that combination an MRI is likely to pick up further but as of yet unsymptomatic pathologies.
I am not sure if this helps but thought i would put something in and I wish you all the best.
Rich