The backbend is one of the best ways of building strength and flexibility simultaneously along the posterior chain. The thoracic extension and spinal articulation will absolutely improve your mobility and performance while practicing every other exercise in existence.
It's one of the best examples of challenging your posterior chain with minimal equipment:
- Wall crawl x 2 reps (be able to go into and out of from both sides)
- Stand-to-stand bridge x 1-3 reps
If you work out in the afternoon, use this in the beginning of your workout. If you train in the morning, use this at the very end of your workout, when your core temperature is highest.
When you emphasize your breathing while going into and out of this extreme position, you'll also notice an improvement in your lung power and capacity during following workouts.
Ease up and practice the wall version with a waist or knee-level box behind you as the finishing position for your hands. Another way to practice going into and out of the bridge would be on the ground or a higher platform from the crab reach position: