Cobra
Physical Therapists call it the prone press up (PPU) and McKenzie trained therapist call it extension In Lying(EIL). Whatever the name, this exercise is very helpful for lots of people with back pain.
Do not worry about pinning your hips down to the mat or treatment table. Just relax the hips and let them sag as you press up.
If you have pain going down your leg, monitor if this pain goes further and further down the leg: this should be avoided. If the pain goes less and less far down the leg, we call this centralization, this exercise is very much indicated for you. No need to hold this stretch, just repeat 3-5 sets of 10 reps, several time a time.
Child Pose
PTs like to call this the kneeling stretch, or prayer stretch.
This is a great stretch for people with low back pain that respond to flexion.
Do this in 3 directions: arms straight forward and with both arms either to the left, or the right. Hold for about 10 seconds and do at least 3 reps in each direction, several times a day and encourage slow deep breathing throughout.
Cat/Cow
Cat-Cow, or sometimes called cat/camel, is a gentle flow between two poses that warms the body and brings flexibility to the spine. It stretches the back, torso and neck, an it also opens the chest, encouraging the breath to become slow and deep.
Start on hands and knees: crawl position.
Begin by moving into Cow Pose: Inhale as you drop your belly towards the mat. Lift your chin and chest, and gaze up toward the ceiling. Next, move into Cat Pose: As you exhale, draw your belly to your spine and round your back toward the ceiling. The pose should look like a cat stretching its back.
Downward dog
Start in a crawl position (on hands and knees) so that your hands are under your shoulder and your knees are under your hips.
Next, walk your hands forward and then lift hips up towards the ceiling as you straighten your knees and elbows as shown. Tighten your quads and if able you can lower your heels to the floor. Hold this position. Slow deep diaphragm breathing the entire time.
Triangle pose (with block)
Physical Therapists sometimes call this a standing windmill.
Start in standing position and take a step forward so that your front foot is pointed forward and your back foot is pointed to the side. Both knees should be straight.
Next, bend forward hinging at your hips and hold a Yoga block for support. Reach your other arm up overhead and turn your head to look upwards as well. Hold this position. Slow deep diaphragm breathing the entire time.