First of all congratulations for the new life bless the baby with health and happiness,
Understanding the postpartum back pain is very important so you can tackle it easily, two main reasons 1 st because of the heavy belly for the last few months you slowly start walking bending backwards which leads to increased lower back curvature More than normal it's called postural problem,2 nd the muscle of abdomen and pelvis have become week because of pregnency,
Solution for it,
Start with postural correction exercise life bending forward backwards rotation simply if u can follow Surya namaskar it includes all that is required start with 2 or 3 then slowly day by day increase the number.
Start pelvic floor muscles strength and abdominal muscles strength if u have pan doing this start doing it will belt on later you cand do it without it.
Next Steps
connect for detail assessment and treatment plan
Health Tips
use a hot water bag to reduce pain, use a pillow under your back while sleeping, side lying will help more