Parsvottanasana, aka Intense Side Stretch, stretches your hamstrings as it lengthens your spine. It stabilizes and challenges your balancing abilities and energizes your legs.
However, sometimes the relationship between the hamstrings and back needs to be brought into balance. For most of us, moving too far forward in the pose will cause the back to round and the front torso to contract. There is a variation that allows the front body to rest on the front leg, but for most of us, the greatest, most expansive benefit comes from keeping your torso long, parallel to the floor or higher. This allows your torso to stay more open so that you can breathe more expansively.
If your back rounds, causing your front body to contract when you place your hands on the floor, Yoga Blocks can help. Placing your hands on Yoga Blocks not only effectively “raises the floor,” but it also gives you something substantial to press into to help you lengthen your legs and torso even more.
• Stand at the front end of your Yoga Mat in Tadasana (Mountain Pose) with your feet hips width apart.
• Place Yoga Blocks on either side of your feet so that they are at their tallest height.
• Step your right foot back a distance approximately equivalent to the length of your leg, so that your feet are still hips width apart from left to right.
• Do not square your hips. Allow the hip of the back leg to go with the back leg.
• Place your hands on your hips and begin to bend forward, leading with the pelvis. In other words, hinge forward from the pelvis, moving the pelvis, waist, rib cage and head together.
• As you bend forward, press through your left (front) foot to begin extending the left hip back.
• Place your hands on your Yoga Blocks. Press your hands into your Yoga Blocks and simultaneously extend the left hip back.
• Feel free to adjust the height of your Yoga Blocks. Just make sure that your torso stays long front to back, and your breathing stays free and easy.
• Stay for 30 seconds or more, breathing deeply.
• Press your feet downward to lift up to standing. Step your right foot forward and relax in Tadasana before moving to your other side.
Here’s a post that describes all the options and how to choose the Yoga Blocks that are best for your personal practice.