Yoga term: Adho Mukha Svanasana
Points of alignment:
Hands flat and shoulder width apart. Arms straight with elbows facing the sides. Shoulders are back while shoulder blades are pulling down. Back should be straight with a slight arch in the lower back created by a reaching of the tail bone towards the sky. Legs are straight with the heels reaching towards if not touching the floor. The front of the legs are active while the backs of the legs are stretched. Lift toes towards the shins. Knees are rotating in slightly and the feet are about shoulder width apart. You should also be pulling in from the lower abdomen. The rest of the front of the torso and abdomen is active. The head can be looking forward or back towards the feet with the chin tucked.
Note: This pose is a good opportunity to lock and strengthen the Bandhas. By squeezing them and using them to pull the body into alignment. Depending on how long you hold it a degree of energy is opened, increased and pushed into the body. This exercise also increases sexual prowess and stamina.
For the above picture: By bending a knee the weight is shift to the one straight leg giving a greater stretch to the back of the leg. By switching leg at a few second intervals this can be a good warm up for your first entrance into downward dog.