Stand erect, hands by the side of your body. Stretch your left leg outward and turn your left foot to make a 90 degree angle with the leg. Take a deep inhalation and lift your right hand above your head while your left hand touches the left foot. Alternatively, you can place your left hand on a block for support. Make sure that your thighs are engaged. Gaze towards the fingertips of the right hand. Breathe deeply and hold the pose. Taking a deep exhalation, relax, lift your body and come back to the starting position. Repeat the same with the other side. Make sure to keep your spine erect during the entire back pain yoga process.