If your back is still feeling good after the preceding exercises, you can add a little rotation of the trunk with Pilates saw exercise.
Begin Pilates Saw:Do this gently:
Sit up straight.
Your legs are extended in front of you about shoulder width apart. If you have tight hamstrings you may need to prop your hips up on small lift, like a folded towel.
Keep shoulders down as you stretch your arms out to the sides, even with your shoulders.
Inhale: Get taller as you turn your whole torso, but use your abs and keep your hips even with each other. Your gaze goes with your spine.
Exhale: Let your gaze follow your back hand as you stretch forward and reach the pinky finger of your front hand across the outside of the opposite foot.
This can be a small move. It is most important to keep the hips down and even.
Once your reach extends to its furthest point, maintain your turned position as you inhale and return to sitting.
Exhale and undo your rotation, coming to the starting position.
Repeat this exercise 3 times to each side.