hi there sweet one,
Based on my expirience, quadruped on red thera ball will help. then slowly progress with trunkal extensions. Once done, you can progress by putting one UE/LE in extension. It would be better if I could demonstrate it to you. Anyway, Axial rythmic joint compression in short sitting can give you an automatic improvements. I tried it many times.
God bless and more power.
Your friendly neighbor from Philippines.
ENZ