--but everyone knows I'll chime in anyway.

Too many orthopedic specialists and other doctors read the gospel about how 95% of the time sciatic nerve distribution problems are traceable to radiculopathy at the L5 or S1 nerve root levels, so they don't think to look lower.

But in the lumbosacral plexus, the sciatic nerve (and others) has contributed communicating fibers from many levels, including lower ones such as the S2 and S3 nerve roots. But a standard lumbar MRI only images down to about the S1 level, and since the the S2, S3 and S4 nerve root areas come through the sacrum, the triangular bony area that is held between the iliac hip crests, they are not imaged. AND, since the sacrum is a fused, fixed bone that is held rigidly (in "normal" people) to the pelvis at the sacroiliac joint, and doctors have been taught it rarely has problems, they don't think to look there, and often dismiss the possibility even if you mention it.

But there are certainly cases of sacroiliac joint dysfunction, in which the sacrum has more "play" and move more than it should, and this can lead to nerve impingment. One would think that docs would be more open to examining this in cases of traumatic injury, such as motor vehicle accident, but I've found even then they're hard to persuade ("that joint is the strongest in the body", etc.). It takes an open-minded doc to have that lower area MRI-ed. Many will take plain X-rays to look at the hip joints, but few will look directly at the sacroiliac joint area and the sacrum specifically.

(Sorry this isn't one paragraph, Mel--but you might want to print out the whole discussion, as well as some of the articles about sacroiliac joint dysfunction on our Spinal board.)

And, yes, Mel, with my leg length discrepancy, I've thought about a lift for the left shoe. I've tried a few of the commercially available ones that slip inside shoes, but they don't seem to help much, and they slip around a lot. It may well be that I will have to have one specially made--or have shoes specially made (that gets really expensive, since you can't really have it done for only one pair).

Fortunately, I have now found a physical therapy practice which seems to be sympathetic to the idea of sacral problems secondary to malrotation/malpositioning and is working with me in that area--myofascial release, nerve gliding, etc. They can clearly see my hips are not exactly even, and that when I lie down my legs are not even. (It "feels" as if my left leg has been "shoved up" into my hip joint and rotated about 10 degrees to the left. I don't remember a specific traumatic event, but I have done lots of running and basketball playing over the years.)

In any case, it takes an open minded doc to really look into that area--perhaps a physiatrist or more osteopathic person. But any condition that is altered significantly with different positions cries out for that sort of structural analysis.