The root lock, or Mula Bandha, is defined by B.K.S. Iyengar as “a posture where the body from the anus to the navel is contracted and lifted up and towards the spine.” There is a system of energy that starts at the base of your spine, or root, and runs up your spinal column to your skull. With this logic, by using your bandhas, you can control the flow of energy within you.
The lock is located at the base of your spine, or directly at the pelvic floor. This lock is hard to pin-point so the broadest way to get in touch with this area, is by starting with the anal sphincter. You must start by contracting and relaxing all the muscles down there. Sit, breathe, contract and relax, holding for a second. As that becomes more comfortable, work your way up to holding those muscles for longer periods.
Once you have mastered tensing all the root muscles, the focus then is on isolating and contracting independent muscles.
The purpose of getting this close and personal with these muscles is to integrate the full mind-body connection. Contracting your root lock can affect many systems of the body and your inner energy. Using these locks can transform your practice by adding stability in poses and keeping energy from leaking during meditative practice. Having control of these locks is to also have control of your life force energy.