Start on your hands and knees (hands are shoulder distance apart and knees are and hip distance apart)
Exhale and round the back, tucking top of head towards belly button. Inhale and arch, tipping tailbone and head up to ceiling, opening up chest.
Do this several times.
*If you want to add some abdominal contractions that will support the spine, try this:
Keep spine in neutral (imagine your back is a coffee table.) Tops of the feet are on the ground (you may want to put padding down if feet are stiff.) Inhale and as you exhale, "shrink wrap" your abs and lift knees off the ground about an inch. It's not about height, it's about feeling the engagement of the abs. Stay up for as long as you can, lengthening the head and tailbone in opposite directions. Do this several times.