There is no such thing a low back "STRENGTH"
A contentious statement to say the least, but its intent is not to be purposefully polarizing, its intent is to help inform us of better exercises to choose when looking to have either a direct, or indirect effect on the lumbar spine.
When we say something is "weak" we begin our crusade to add resistance in order to build strength, as we move a muscle from origin to insertion against said resistance. This thought process, when applied to the muscles of the lower back can be ineffective and potentially harmful. And to someone in pain, ineffective and harmful, quickly become the same thing.
So rather than performing low back extensions, side plate crunches or supermans for low back strength. Focus on low back STABILITY and utilize exercises like:
- Ab wheels,
- Copenhagen planks
- Single-leg rdl's.
Then, as an adjunct, factor in the role of mobility and stability of the shoulders and hips, and how those factors will allow you to train the strength of your lats and glutes.
This multi-faceted approach to the lower back, along with a few other factors will drastically improve your pain and performance around the low back.
https://www.youtube.com/watch?v=CeyczsdO5lo
Stay Strong,
Jordan