Also known as Thunderbolt pose, Vajrasana is a Meditative Pose. This is a restorative position used in between Yoga sequences to rest.
This is a great asana for improving your digestion. It is normally recommended to sit in Vajrasana post lunch/dinner. This pose also calms down the nervous system. In this post your vagus nerve is gently pressed and results in overall wellbeing.
You can start getting into Vajrasana from All fours position. Feet extended in the back will help you hold the position in a long time.
Start from Dandasana. Fold your legs and come up to a seated position. Big toes touching each other. Knees touching each other. Rest your palms on your thighs. Spine straight.
Sit between the heels. Heels can be separated.
Slowly straighten your body - legs stretched out in the front. Palms on the ground.
If you have knee injury place a cushion under the knees. Same for ankles, put a cushion under ankles.