Adho Mukha Svanasana (Downward Facing Dog):
Mechanics: This pose resembles an upside-down V-shape. The hands are placed in front of the head at approximately shoulder-width distance. The palms and undersides of the knuckles of the fingers are pressed firmly to the floor. Typically, the fingers point directly forward, though depending on the level of comfort in the wrists, the fingers can point inwards or outwards as well. The upper arms are activated, and there is a slight inward rotation so that the armpits are directed towards the face, and the soft inner part of the elbows are directed forwards. Those with hyperextension in the elbows may wish to maintain a small bend in the joint to avoid over-extension.
The feet are approximately hip-width distance apart, and the heels may remain lifted or press all the way down to the floor. The feet are parallel and the toes point forward. Knees may remain bent, or the legs can straighten. The hips lift up into the air, and contraction of the lower abdominal muscles assists in raising the hips away from the floor.
The back is straight, the shoulders release down away from the ears, and the back of the neck remains relaxed so the head falls towards the floor.
In general, the appropriate distance between the hands and feet can be found from transitioning from an upper plank position into downward facing dog, though the distance may be smaller depending on your body and flexibility.
Benefits: Downward facing dog stretches the entire back side of the body while strengthening the front side of the body. Though it is considered a resting pose, for many beginners, and even those with years of practice under their belts, the pose is extremely challenging. It simultaneously offers tremendous stretch along with strength.