I have been doing Taekwondo for years. Now I'm looking for a martial art that doesn't do jump kicks. Regular kicks are fine. I have problems with my knees so anything with jump kicks, low knee bends, kneeling to the ground, etc are painful. I love doing forms so I want a style that has a lot of form work, just without so much jumping.
Here are a small list of styles to look into. They're all hand dominated and have forms:
- Wing Chun kung-fu
- Southern Praying Mantis kung-fu
- Hung Gar kung-fu
- Pentjak Silat
- Taiji (Tai Chi)
Many other styles would qualify.
For example, I listed a few southern styles of kung-fu up there. There are a lot more southern styles than that. And they do tend to be more hand-dominated than the northern ones. Northern kung-fu styles tend to be longer in range and utilize kicking to a much larger degree.
You might want to reconsider your requirement that it must be a style with forms. Maybe take this opportunity to pursue something completely different from what you're used to. In that case, you might consider doing Brazilian Jiu-jitsu or Judo. Just a suggestion. You might discover that you like it even more than your original martial art.
Consider also Kali / Escrima. It's a stick and knife based martial art from the Philippines. There's very little emphasis on kicking. You probably won't be shown forms, but there will be two-person drills that involve multiple steps. I mention this, because it's very practical and opens the door to a whole knew world of weapons based martial arts that you're probably not familiar with. This martial art is mostly stand-up and upright, but there are some drills and techniques within it that are practiced in very low stances that could be hard on your knees. For those occasions, rare as they are, you can easily just sit it out.
Another thing to think about is that if your knees are seriously screwed up and getting worse, most of these martial arts will still require you to go deep into stances and put a lot of force on those knees. Sometimes they require you to really torque the knees or bend them in weird, unnatural ways. In that case, you might want to go into Taiji. And if you do, consider Wu style taiji, as its stances tend to be higher and shorter.
Hope that helps!