Dr. O’Sullivan in 2021, summarizing his 2012 editorial in the British Journal of Sports Medicine:
I used to believe instability in the lumbar spine was a thing — even published about it — but the evidence just didn’t stack up. Discussed here [full text PDF].
A nugget from the editorial:
“It is now clear that there is little evidence to support the view that ‘instability’ underpins the basis of disabling non-specific chronic low back pain. There are no studies that demonstrate a clear relationship between spinal or pelvic mobility, degenerative processes, pain and disability.”
O'Sullivan P. It's time for change with the management of non-specific chronic low back pain. Br J Sports Med. 2012 Mar;46(4):224–7. PubMed #21821612 ❐ PainSci #52124 ❐