45 with back issues... Shorin Ryu or Danzan Ryu?

I'm ready to get back into MA. Looking to take classes with my 12 yo.

I've been on and off with back issues, never really getting any consistency. I've tried a few different styles, and I understand differing styles and types of MA.

At the moment, I'm looking at Danzan Ryu jujutsu, and Shorin Ryu karate.

For me... I'm not under the illusion that I need to learn self-defense. I just want to learn a martial art to incorporate into a sort of physical meditation.

For my son... I want him to do something physical that will help his athleticism to incorporate in other sports... He used to do Judo, and that helped a lot with football.

Please share your thoughts and opinions. 🙏