This is the Downward Dog pose. Adho Muka Svanasana
Place the palms flat on the floor and raise the tailbone up.
Lengthen the arms out. keeping them in line with the spine or choosing to dip around the shoulders a bit.
Turn the tailbone upwards and push the heels downward.
Pushing the heels towards the floor draws the tailbone down. This causes a curl in the lower back. Do not sacrifice the position of the lower back when trying to get the heels down.
Pushing down on the fingers can reduce the strain on the wrists.
This is a pose that strains the wrists in a lot of people. The use of the elements can prevent the wrists from feeling strain. This is achieved by pushing the fire element through the fingers intensely. This Engages the muscles in the wrists and allows the air element to enter between the forearms and wrists.