Several years ago I did a workshop with a well-known Sydney physiotherapist who was a practitioner of Ashtanga Vinyasa yoga. She schooled us in how to assess ourselves for any back problems we might be suffering.  Then, she gave us a few poses that are useful in ‘re-booting’ one’s back after long sitting or standing sessions.
This is the pose from that workshop that is my favourite for de-compressing my lower back, especially after all the car travelling we do because we live remotely.
Really, all you’re doing here is a tractioning stretch, while hanging off a rail, knees slightly bent. To get the most out of it, you lengthen the sides of your body with  your tailbone tucked under a fraction. Hold for 30 seconds or so, take a break and repeat.
Having just returned from a 4 hour drive, with no time for a yoga practice upon arriving home, this pose has set me straight for the evening – until I get to the yoga studio in the morning.