Child's pose is an easy and restful stretch for the back.
Begin Child's Pose:
Start by kneeling on your mat with your butt on your heels.
With your toes together, open your knees to at least hip distance apart.
Lean forward and drape your body over your thighs so that your forehead rests on the floor.
Reach your arms out in front of you. Alternately, you can leave your arms along your sides. Try both and see which feels best to you.
Breathe deeply and relax. Release any tension you might be feeling in your lower back, neck, or hips. Give this exercise time to work. It can take a few minutes to allow your body to relax into the stretch.
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