Vajroli Mudra वज्रोली मुद्रा
Vajroli Mudra [Thunder Gesture]. Vajroli वज्रोली refers to "a certain position of the fingers." The term derives from vajra वज्:, tunder, lightning, diamond, adamantine, particular sitting posture.
This gesture refers to the sexual energy. It involves therefore the lower pelvis. The contemporary form(*) of this gesture is based on the contraction of the lower pelvic system and the focus on the ascension of the energy which is pulled from bottom to top through the spine.
(*) A classical variant consists in the absorption of liquid through the urethra.
The legs are first bend in front of the body, with the sole of the feet on the ground. The yogini stabilizes him or herself on the ground with the fingers stretched at the level of the knees or closer to the body at the level of the hips. The area of focus is the pubis. The concentration is on a point in space. The eyes do not move from this point, which constitutes the center of stability during the position.
During an exhalation, the trunk tilts slightly backward, the legs are stretched while keeping the back straight. This generates an angle between the trunk and the legs. This angle should be as small as possible. The whole holding of the angle is conditioned by the contraction of the pubic area and of the root.
Next, the breathing occurs in Visamavritti, or in a easier mode following 1/2/2 (i.e. in 3/hold 6/out 6). The gazing point is seen between the knees. The difficulty of this posture consists in avoiding a strong contraction of the thigh muscles which can lead to cramp, or flexing the knees.
The gesture is maintained as long as possible through the breathing control, the ocular fixation, and the pubic and root contraction. Finally, during an exhalation, the posture is halted and the yogini rests until coming back to neutral. The posture is repeated at least once.
After the last gesture, adopt the corpse position, palms upwards and focus on the internal movements, eyes closed.
Natha Yoga Version
This version is closer to the tradition. The gesture occurs in any sitting position such as Sidhasana. The hands adopt Shakti Mudra (triangular gesture) at the level of the pubis.
The contraction solely involves the genital muscles. The other pelvic muscles, i.e. anus sphincter, are not involved. This neuro-muscular isolation is difficult and requires time.
Once the muscular isolation achieved, the yogini further the differentiation at the energetic level. Here, a difference must be perceived in terms of sexual energy and primordial energy. The first one is unavoidably that of sexual pulsions and sexual desire, the second is pure, non differentiated and without true object.
If the student perseveres, the eyes focus on a point in front of him or her. The breathing techniques is Visamavritti with Kaki Mudra (tongue protruding outwards) during inhalation. This brings the air deep in the throat, down to the genital system. Then, the tongue goes in, still in a tube form and propping against the upper part of the mouth. During the full lung retention, the pubic muscles are alternatively contracted and relaxed while attempting to discern the pure and sexual energies. The enunciation of the Hrim bija is practiced during every contraction. Exhalation occurs through the nose, and so forth.
During a last phase, close the eyes, and according to the same breathing pattern, the retention occurs as follows: bring up and pull the pure energy with a continuous contraction of the genital muscles towards the fontanel. Apply the "hrimn" Bija continuously, while moving the eyes into Shambavi Mudra. Breath out through the nostrils, and so forth.