Back roll

Lying on your back, take hold of your knees (or if you can reach, all the way around your shins as pictured here). Rock gently from side to side. It’s a great way to stretch and massage your lower back after a long day.

Let your legs and feet completely relax. At the same time, let your shoulders melt toward the ground — be sure not to tense them while holding your knees. And of course, breathe deeply.

Supta Matsyendrasana – Reclining Spinal Twist

Lying on your back, prop up your knees and then let them fall over to the right side. You can stabilize your legs by holding the left thigh with your right hand.

But at the same time, stretch your left arm out to the left and gently roll your head to the left.

Here too, you want both shoulders to relax into the ground as much as possible. And yes, breathe! Then repeat the pose on the other side.