Back issues tend to be genetic. You will hear of doxies who were overweight, ran up and down the stairs, jumped all over the place, and never had a problem... and there are those whose owners were extremely careful to keep them lean and restrict jumping, but the dog still had recurrent issues. But it's a good plan to keep them lean and healthy and give them regular exercise... and try to keep them from jumping excessively or off very high things onto hard surfaces (Angel had her first issue shortly after jumping over a dog gate onto a hard tile floor), or twisting unpredictably. They are wild little daredevils and believe they can fly.
And then you just cross your fingers
and know what to do if the dog does show signs of a back injury.