Backbending used to hurt a lot when I was first learning. Now it feels energizing and amazing. If you try backbends, and at first it feels like, "WTF are you talking about, Christina?!" keep trying.
Many of these movements our bodies have not done in decades or ever. Sometimes the sensational feeling (you may call it pain) is tied in with fear and a lot of other ways our bodies' animal instincts fake us out, trying to get us to stop, thinking its protecting us and our vulnerable soft bellies.
But if you can breathe through what I like to call these "sensations," you'll be ok, family!
Moving Forward & Backward in Urdhva Dhanurasana
Rocking the weight forward and backward between the hands and feet. This movement may look subte, but it's an essential step to eventually standing up from Urdhva Dhanurasana.
It's easier to stand up when you're coming from a deeper backbend, so if you're trying to learn this, maybe come down to the top of the head and walk the hands in.
Using the Wall
You'll probably want to warm up with some backbends from the floor before getting into these. Walk the hands down more each time. Stretch the arms straight to deepen the backbend before standing back up. That's the deepest part of the backbend, so keep breathing.
If you hear popping in your back or chest, that's a good thing! Tension and blockages are being released. Shake it out. Follow with a forward fold to round the back.
To the Floor & Up
Dropback/standup is much more about persistence and overcoming fear than it is a physical thing. It may feel unnatural at first, but the key to making this happen is coordinating breath to movement. Exhale down. Inhale up.
Physically, the most important part is just to pretend there is glue under your feet. The strength to stand up comes from rooting down into the feet and drawing that energy up through the legs, hips, and back, ending with the top of the head. You'll see how the energy moves through my body in the first video, especially as I gain more focus and control.