There are "pointy" rubber mats to put on furniture to discourage pets from jumping up, but they aren't really practical.
I understand your problem. Both of my boys have had neck/upper back strains and I had great difficulty discouraging them from jumping. I have had my mattress on the floor for almost 10 years because of Max.
Seriously, my box spring is a headboard and I have no bed frame. I never could stop him from taking flying leaps off the bed.
Another friend whose Yorkie has severe back problems, she had to put xpens around her couches.
The only thing I can recommend is confining Thumper when you can't supervise to an area without furniture and give him a really comfy bed to enjoy.