When you are doing hamstring stretches in yoga class, you might notice that one leg is harder to stretch. That is normal, most people do have one leg longer than the other. You don’t have to be symmetrical: just flexible and strong. Get into the feeling of each leg, and try to find the place where they both feel equally stretched and loosened. I like to think I’m getting in touch with my bones.
In anatomy class, I found out there a good reason one leg is longer than the other: when we stand in a 3-D gravitational field we compress in a spiral. That is the geometry of bipedalism, two lengths in motion in a gravitational field will make a flunctuating spiral. We need that flexibility, and that is one thing that yoga will give us.
The problem with pain in this area happens when you lose flexibility and your sacrum gets stuck. This sets up a cycle of cascading problems that lead to more back pain, muscle spasms, and the slowing or stopping of the cerebrospinal fluid. All vertebrates have this fluid in their brain and spine. CSF acts as a cushion or buffer to the brain and the spine, as well as a regulatory and immunological function. There is a channel, called the central channel, that runs through the vertebral column where this specialialized fluid moves from the brain, through your neck, and to the sacrum. It moistens and nourishes the brain, the spinal cord and the nerves.
The movement of this fluid can be restricted by imbalances in the neck and the sacrum. Yoga provides a way to get these two important parts of your structure back in balance. If you find imbalance in your legs in your yoga practice, gently persist with your lengthening and strenghtening exercises, it will help you with the back problems.
Just let go of perfection and enjoy the journey.