For the longest time I've been preaching a stable lumbar spine and how to train it, how to brace it. I'm not dismissing this method at all. It should be trained. A heavy deadlift requires it. I've been reading Stu McGills stuff since the beginning.
As you can see from the above video, the lumbar spine is trained to be "stiff" to not allow movement to take place. I've been doing this for years. I still occasionally get back pain. Len Kravitz wrote a great article about the potential mechanisms of low back pain and did a review of some McGill work.
"Research now shows that nominal daily task, as well as strenuous ones may result in spinal buckling. Computerized analysis of this phenomenon suggests that there is momentary reduction in neural activation to one or more of the deep intervertebral muscles, resulting in this spinal segmental buckling leading to tissue irritation or injury."
The recommendation would be to learn to stiffen all the muscles that support the lumbar vertebrae. I now firmly believe this is only half the solution.
I was exposed to the concept of PRI (Postural Restoration Institute) last year and started incorporating the concepts of their breathing exercises. Many people have a lumbar spine that is actually fully locked into extension. They don't have the ability to flex the spine, even when it is rounded it is still stuck in extension. Below is a video of Tony Gentilcore demonstrating a simple drill to do to help facilitate diaphragm breathing and unlocking extension. Remember the spine should move. Joints should move!
Often when one joint becomes hypo mobile, the next joint above or below becomes hyper mobile. It's the hyper mobile one that can bring the buckling and pain. Remember the thought is that the level that buckles is moving to much and that there is potentially reduction in neural activation to one or more of the deep intervertebral muscles that then allow this.
Neural reduction can happen when something doesn't get used. Ever try to lift only your big toe without lifting any of your other toes? So how do we go about increasing neural drive to the intervertebral muscles? Enter Functional Range Conditioning.
The idea is to take just a cat/camel exercise and create intersegmental cat camel. Every segment should be able to go into flexion and extension. When evaluating it, often there will be a block or area that doesn't have movement and the person doesn't possess volitional control. If this is retrained, spinal mobility under control is achieved. Remember anything that moves should be under your control. The spine should move.
I've hung out on the side of stability for a long time. To have a true preventative program with the goal of preventing spinal buckling, we need a combination of stability and mobility.