Suggestions:
In the writers humble opinion-
1) you are correct that all chiropractic techniques could be evaluated separately.
2) the correct goal posts for such studies should be patient based e.g.. patients with LBP (of various diagnoses) assessed by Qwestry pain and disability rating are treated with various techniques can be compared using statistical measurements for outcomes.
3) It is essential that those diagnosing the LBP and measuring the outcomes don't know which technique was used - they don't need to even be chiropractors.
4) Techniques: since most people mix and embellish it would be difficult to accurately isolate techniques, however manipulative treatment versus non-manipulative treatment could be easy to assess. We really have to define what a spinal manipulation is first !!!!!!!!!!!!!!!!
There are many of us that would be pleased to undertake such research but who will pay for us? The Major funded his research out of Kodak didn't he?
I hope this helps
Tim Young, DC
Australia