I need some instructions to help me to stretch my back and my pelvic muscles.

Minnie O.
There's about 3 stretches I know for this. Butterfly stretch, wherein you sit on the floor with your feet together and push down on your knees. Modified hurdle strech, where you keep one leg bent and one leg straight on the floor and reach out to your toes, ankle if you can't. And pidgeon (?) stretch where you keep one leg perpendicular to your body and straighten the other out behind you then straighten your back and sink down on your hips.

R Di A.
Gooogle yoga for back and pelvic muscles and select one of the YouTube videos. I like the “Yoga with Adriane” videos which are short, easy yoga instruction videos that get very specific on what areas of the body you want to focus on.

Astrid G.
I like to lie on a bed pull my knees up to my chest and arch my back. Also sitting in the floor, in a criss cross applesauce style or Indian style, and grab my hands while they are high above my head reach towards the sky.