Rebounders or Mini-Trampolines have come a long way.  Just a few years ago, the only kind you could get were with springs.  Nowadays, you can find several brands with bungee cords.  The are softer and create less compression for your spine.

I found one of them on Amazon that I think works great and doesn’t cost a lot.

It is the

DARCHEN 350lbs Rebounder Mini Trampoline for Adult, Indoor Small Trampoline for Exercise Workout Fitness, Upgrade Design Bungee Trampoline for Safer Quieter Bounce [40 Inches]

It is available here: (No JV.)

It is rated at 400 lbs. and 40 inches in diameter.