Remembering to backbend with your upper spine can be difficult, as we naturally tend to collapse in our lower back (lumbar spine). In my former life as a gymnastics coach, the anatomically inclined coaches always knew to teach kids their backbends from the upper back (thoracic spine). This of course prolonged the acquisition of many skills, but once the skills were obtained, they were done correctly and safely and the gymnasts could do more repetitions of the skill, therefore increasing muscle memory and instilling confidence for their competitions.
Backbends can be simple – from just standing in tadasana and lifting the heart towards the sky to chakrasana – but even the simplest backbends done incorrectly time after time can increase compression in the lower spine and tighten the muscles around the sacrum, creating a very tight area in and around the joints. Add that to the amount of sitting the average person does, and you can create even more tightness and asymmetry in this area.
Using a block (narrow end if you can) prop it against the wall and put the narrow end of the block between your shoulder blades. Sit against the block and externally rotate the arms (make your palms face up/forward) and let gravity do the work of opening your collarbones and lifting your heart. Keep a light engagement in the pelvic floor and lower abs so as not to compress the lumbar spine.
Do this for as long as you can, or about ten minutes. Take the feeling of the block between the shoulder blades with you as you try some of your favorite backbends. Maybe you’ve been doing them right all along – if so, great! If not, approach your backbends as though you’ve never done them before. Be ok with NOT going as far as you’re used to because you know NOT to use your low back. Always be willing pull yourself backwards from a pose in order to correct form, or some day you’ll find you can’t do the pose at all due to an injury. Most injuries in yoga are caused by the ego. Some are most certainly NOT, but from what I’ve seen over the years and what I’ve done, I can say many of our ouches and chronic pain come from over-stretching, over-doing, and under-aligning all in the name of trying to look like an ideal we have in our heads.
Also keep in mind that bending backwards requires stretching in the front of the body. So, tight quads, hip flexors, psoas, pecs, external rotators of the shoulders, and more can restrict your backbends. Use the awareness that yoga teaches you to recognize if you need to work on any tight areas.
Remember, there is ideal and there is real. Be real. Pose with integrity. And be sure you can breathe while you do it!