A back in pain protects itself. The muscles either side of the spine tighten and stay tight. That part is normal, and it is meant to happen.
What is not meant to happen is that they never switch off again.
Weeks become months. The tightness stops being a response to anything in particular and simply becomes the baseline you wake up with.
Which is why the ache is loudest first thing in the morning — before you have lifted, carried or sat through a single thing.
And why leaning on a shopping cart helps. Bending forward takes load off muscle that has been braced for hours. Standing upright puts it straight back.
Lumbrace is built for that one problem: warmth to reach the muscle, massage to work it, and a slow stretch to open it out again.