Upward Facing Dog (Urdhva Mukha Svanasana) opens the chest, abdominals, and the front side of the body while strengthening the shoulders, triceps, forearms, and low back. It's another one of the foundational poses in a vinyasa flow sequence and important to get correct to avoid injury. This posture is great for resetting your posture from sitting at a desk or from a slumped-forward posture.
From Chaturanga Dandasana, on your next inhale, straighten your arms and drop your hips towards the mat.
Rollover on your toes and change your foot position so you are resting on the tops of your feet. If you can't roll over on your toes, try flipping your feet one at a time.
Actively roll your shoulders back, draw shoulder blades down, open your chest, and broaden your collarbones to create space between your shoulders and ears.
Engage your abdominals and relax your glutes but try not to let your hips drop to the floor.
Press into your hands and keep knees and hips lifted from the mat. Your only points of contact with the mat should be your hands and the tops of your feet.
Gaze forward, or if it feels okay on your neck try shifting your gaze slightly upwards.
Avoid drawing shoulders up towards ears, instead, actively draw your shoulder blades down and in towards your spine, and pull your shoulders away from your ears.
Avoid disengaging your thighs, and letting hips and legs collapse to the floor as this will add stress to the lower back. Instead, engage thighs together and firmly press through the tops of your feet to lift your thighs away from the mat.
Avoid gazing up towards the ceiling as this will create strain in the back of the neck.
Avoid this posture after the first trimester of pregnancy, and if you have a back or wrist injury.
If it's too difficult at first to roll over feet, try lowering thighs to the ground and flipping the feet over one at a time. After you flip both feet, engage your thighs, and lift your hips off the floor.