This movement can be done with a rope, stick or sheet. you may not be able to go all the way back when you start and thats ok. Stay on the sweet side of the stretch. The front and back stretch is the basic move. Exploring the sides is a more advanced movement.
While lying on your back, bend your knees enough so that your fingertips just touch your heels. Lift your butt o the ground and press your hips toward the sky – palms very actively pressing down into the earth.
This just feels good. Find a comfortable seated postion and sway your spine back and forth. Looks for liquid movement and try to move your spine with your feet and legs.
So often in left we are seated, or on a forward flexed position. Opening the front is absolutely critical to back and spine health. These simple techniques are easy to do and feel great.