Let's begin by opening the hip flexors and spine.
Sit on the floor with your right knee bent and your left leg extended behind you. Place your hands on your lower back and gently arch your back. You should feel a nice stretch in the front of your left hip, but if this variation is painful, lean forward, placing your hands on the floor in front of you. Hold for five or more breaths, and then repeat this pose on the other side.
Here's a more detailed explanation of how to do Pigeon pose.