Supta Vajrasana, or the reclined thunderbolt pose, involves lying on your back with knees bent and feet close to hips. The technique involves arching your back and placing your head and hands on the ground. Benefits include flexibility, improved posture, digestion, and relaxation. It may help conditions like back pain, asthma, and infertility. Those with injuries or medical issues affecting the back, knees, or pregnancy should avoid this pose.