This is Childs Pose. It's a beautifully simple pose, and it feels great. We often use it as a resting pose in yoga classes, but it's a great stretch for your lower back too and helps you to breathe into the back of the lungs. Also a deeply nourishing pose, it’s very calming, grounding and releasing and it helps you to bring your attention inward.
There are many different ways you can place the arms and hands, and each one uses your muscles slightly differently.
Yoga poses should fit your body (not your body fitting a rigid yoga pose), and how it feels in your body in the moment you are doing it. That might well change day by day, or moment to moment. Give these options a go, and see how they feel to you. And next time you practice, you might find a different version feels better in your body in that moment.
There's a sheet about childs pose to download here.
Childs Pose - how to do it:
From all fours exhale and lower the hips to the heels and the forehead to the mat - or onto a block, book or cushion if that feels better for you. Or even turn your head to the side, resting your cheek on the mat (ideally turning the other way midway through, to keep the neck balanced). Have the knees together or if more comfortable, spread the knees slightly apart. Close your eyes and breathe gently and smoothly.
You can bring the arms overhead, with the palms on the floor or with the tips of the fingers on the mat (image 1 above). Alternatively bring the forearms to the mat, bend the elbows and press the palms together (image 2). Or bring the arms by your side with the palms facing up, or facing down (image 3).
Breathe with long, full, slow, deep breaths in all versions of the posture, actively pressing the belly against the thighs on the inhale. By focussing on deep breathing you calm your mind and activate your parasympathetic nervous system, which helps counteract stress and aids relaxation.
To come out of Childs Pose place the palms under the shoulders and slowly inhale up to a seated position. Enjoy the way you feel now.