To enter the posture, begin in a kneeling position with the knees hip-distance apart. As if preparing for Ustrasana, take a moment here to lift the chest and bring the pelvis forward of the knees. When ready, take the hands back to the ankles and grip firmly with straight, strong arms. Pull the pelvis forward, lift the chest, and with an exhalation, drop the head back and lower the crown or hairline to the mat, keeping the arms straight throughout the transition. Do not take weight into the head. Stay for five breaths.
The quadriceps and psoas must work strongly to control the spinal extension as the head is taken back. Without committed activation of the legs throughout the entry and hold of this posture, you will not likely make it out the same way you came in. The proper exit from Laghu Vajrasana is more challenging than the posture itself and must be kept in mind throughout your stay in the backbend. After five breath cycles, inhale as you scissor the inner thighs and push with all your might into the hands and tops of the feet to pull yourself back up to the starting position. Remember to keep the head back as you emerge or the low back will collapse and the burden on the thighs will be increased, causing a tendency to fall back down.
If it is too difficult to take the head all the way to the mat, build control by lowering only part of the way with the exhalations and lifting back up on the inhalations, continuing the motion rather than pausing for five breaths in order to ensure that the legs stay active and the breath is moving.