The first bandha is called Mula Bandha, which translates as “root lock.” The root referred to here is the root of the spine, the pelvic floor or, more precisely, the center of the pelvic floor, the perineum. The perineum is the muscular body between the anus and the genitals. By slightly contracting the pubo-coccygeal (PC) muscle, which goes from the pubic bone to the tailbone (coccyx), we create an energetic seal that locks prana into the body and so prevents it from leaking out at the base of the spine.
Mula Bandha is said to move prana into the central channel, called sushumna, which is the subtle equivalent of the spine.
Locating the PC muscle might be difficult at first. It has been suggested that one should tighten the anus, or alternatively contract the muscle that one would use to stop urination, but these indications are not entirely accurate.
Mula Bandha is neither of these two muscles but located right between them. These suggestions have their value, however, offering some guidance until we become more sensitive and are able to isolate the PC muscle more precisely. For females it is essential not to mistake Mula Bandha for a contraction of the cervix. This contraction tends to occur especially during strenuous activity. Should a woman do this on a daily basis when engaged in two hours of yoga practice, she could experience difficulty in giving birth.
In the beginning we employ mainly a gross muscular lock, which works mainly on the gross body. Through practice we shift to an energetic lock, which works more on the subtle or pranic body. When mastered, Mula Bandha becomes exclusively mental, and works on the causal body.
To become familiar with Mula Bandha, sit tall and upright in a comfortable position and focus on slightly contracting the perineum, which is the center of the pelvic floor. With the exhalation, visualize the breath beginning at the nostrils and slowly reaching down through the throat, the chest, and the abdomen until it eventually hooks into the pelvic floor, which contracts slightly. As the inhalation starts, there will be an automatic reaching upward. Since we keep the breath hooked into the pelvic floor through contracting the PC muscle, we create suction and an energetic lift upward through the entire core of the body. This is Mula Bandha. With this movement the first step is taken to arrest the downward flow of life force, which increases with age and invites death, disease, and decay like the withering of a plant, and convert it into an upward flow that promotes growth and further blossoming.
Mula Bandha is held throughout the entire breathing cycle and during the whole practice. Every posture needs to grow out of its root. This is only finally released during deep relaxation in complete surrender.