I was sent home from PT after two weeks of a 4 week course and was told that I was losing muscle mass even while under their care. I had bad lumbar pain all the way across and quadricep and hip adductor loss. I had trauma from a hard shock up right side from car accident. Ifin your search, try Amyotrophy. I was diagnosed with that plus Periferal Neuropathy. The wasting muscles matched to the Amyotrophy better than Neuropathy. All people are different but you might have had trauma to your lumbar in your job while lifting, etc. Yes, the effects can be in a different spot than one would think. My pain moved from lumbar to hips and buttocks and gradually decreased until now. I am patiently waiting for muscle and strength gain but feel that it is not respondent to the demands that I place on the particular muscle groups. Perhaps nerves that have been damaged have to reconnect at their own pace and pushing myself does not accelerate the process. Cover yourself by good nutrician, excersise to tolerance, get 5+ hrs sleep, and if the pain gets too bad, seek help for that also. Maybe you are in an acute phase that had to be waded through. I am gaining strength but it is slow as I am approaching two years post accident. Good Luck, Ken in Texas.