Poor conformation, the way your dog's skeleton formed, cannot be changed through core conditioning. But conditioning can make a significant difference to how well the body manages and compensates for it.
Poor posture is different.
Posture is dynamic, it can be improved. But left uncorrected over months and years, poor posture changes how load moves through the joints, how bones remodel in response to that load, and eventually how the structure itself develops.
Posture today shapes conformation tomorrow.