I came across this article last year, shared it on Facebook and tagged a number of colleagues (DC, PT, DO, MD, ATC, etc). Recently it got a lot more attention.
As a clinician who helps patients with back pain on a daily basis I think it is IMPERATIVE that patients know that what they may have been previously told to do is no longer correct. Perhaps it never was.
I'm guilty of it myself. I've utilized technique systems or approaches with patients and clients that ten years ago was all the rage and was 100% right. And it was. It was 100% right back then. Now it's not.
Abdominal hollowing is NOT how you increase core stability. I read a study a few years ago that said something like 80% of patients with chronic low back pain had atrophied multifidi (tiny muscles that connect to the spine). Basically, a large majority of people with chronic low back pain have accompanying core instability. To deviate a bit, we need to define the core:
Internal, external obliques
and to a lesser extent the glute max, latissimus dorsi and trapezius
Abdominal hollowing trains only one muscle in the core. Doing so, based off the above, is literally only training 10% of the core.
Some of the best physiotherapists on the planet have concluded over the last few decades that core co-activation is what needs to be accomplished. The best way to do this is to re-train breathing mechanics and to train abdominal bracing. Doing those two things can then help fire 100% of the core musculature.
You might ask how doing that can affect you? Well, if you live with chronic low back pain, like I did for almost a decade, this may help. Are you an elite athlete and think these concepts don't apply to you? Sorry to burst your bubble, but it's also been proven that proximal stability leads to an increase in distal mobility and overall power output. Basically the more stable your core/trunk is, the more mobile your other joints can be (hips, shoulders) AND you'll be able to generate more force due to it.
The bottom line "core training" is imperative, but you need to do it RIGHT.