Doing Full Backbend, also known as Wheel Pose, isn't exactly on the list of beginner moves. It's demanding both from a flexibility as well as a strength standpoint, so it's best to stick to Half Wheel, Camel, and other easier variations before trying your hand at Full Backbend. When you are ready, here are some things to keep in mind to ensure you're doing this heart-opening pose safely and comfortably.
It takes lower-body strength to hold yourself up in Wheel, but that doesn't mean you need to clench your glutes. Focus on engaging your quads and calves to release tension in your bum, allowing your lower spine to relax and fully extend.
Wheel pose takes a decent amount of upper-body strength as well, and while you want your shoulders to be working, you don't want tense muscles causing neck or upper-back pain. Actively draw your shoulders toward your tailbone and away from your ears, elongating your upper back and neck.
To relieve some of the tension you feel in your arched spine, you might try lifting your heels. Not only is this a way to cheat in this pose and avoid increasing flexibility in the spine (a flexible spine will ultimately make this pose easier), but also, standing on the balls of your feet is very unstable, making it more likely for you to lose your balance and fall. Instead of lifting your heels up, try to step your hands and feet closer together. If that's too challenging on your spine, do Wheel pose with the top of your head resting on the floor.
Turned-Out Toes and Fingers
While it might be more comfortable to hold yourself in backbend with your feet and hands turned out, this is an alignment no-no and actually puts more pressure on your wrists and ankles. Keeping your hands and feet parallel focuses the work in the muscles rather than the joints, strengthening your thighs and upper body and making it easier to hold this pose longer and with less effort.
One of my favorite things to do in Wheel pose is to rock my weight back and forth from my hands to my feet. It builds upper-body strength but also increases flexibility in the spine. When in backbend, notice where you're holding your body weight. If you have a strong upper body or are prone to lower-back pain, you might have your weight shifted into your hands. Likewise, if you have upper-back issues or your legs are the strongest part of your body, you might favor shifting weight toward your feet in Wheel pose. The next time you lift up, try rocking your weight forward and back, and then find equal balance so your center of gravity is at your core, rather than toward your hands or feet.