Ok, let's start from the very start.
You are always training your nervous system. From lifting your coffee cup in the morning to deadlift like a beast in the gym.
Absolutely everything you do, think or say is trining your nervous system.
You just don't know it.
At least not consciously.
You see, the brain is built for survival, thats why don't have any cool reflexes at all.
Like not one!
And in order to survive it's handy to recognise what is happening or about to happen so we can respond in a way that keeps us alive.
We call this prediction through pattern recognition. And it's how our brains work to keep us alive.
Our nervous system remembers everything you've ever done, seen or felt and uses that to help it recognise patterns so it can accurately predict.
This goes for injuries as well.
The brain remembers every injury you've ever had and if it doesn't feel safe doing something or moving in a certain way and wants you to stop, it can bring back an injury to limit what you do.
It's trying to keep you safe by giving you pain because it thinks thats safer than what your'e currently doing.
I know, how sucky is that?
You see, your brain doesn't care that you want to live to 80.
The way it sees it is that you can't live to 80 if you don't survive today. So the brain will only let you move or be strong in the way it feels safest at that given moment.
If it can help you avoid danger in the moment (even just perceived danger) it thinks its doing an awesome job!
Poor movement and/or pain is better than dead.
Your brains priorities are not your priorities, remember that.
If your brain does not feel safe moving, it will shut it down.
If it doesn't feel safe stretching, it'll shut it down.
If it doesn't feel safe lifting, it'll shut it down etc, etc...
So a brain that is trying to survive won't let you move into positions or it wont let you get more flexible or stronger.
Basically, it won't let you perform.
Ask yourself this.
How fast would you drive if your car had no brakes?
Your brain and nervous system is the exact same. If it is under threat, you and what you can do will be shut down.
That means, lifting, standing, walking, stretching, thinking, anything...
How we fix this is by building the brains ability to recognise patterns in movement while increasing the quality of info it takes in so that it has options to move into safely.
This builds confidence and will allow that pesky still lower back to chill out because it feels safe.
Remember, you can do everything under the sun to fix you movement issues but if you don't tackle the root cause, it's going to come back.
Muscles move joints and bones. Nerves and the nervous system move muscles.
Fix the nervous system, fix the problem.