Pretty much everybody before and he has mentioned the major rides to avoid with the fusion (though I am not sure what level yours is at). I am fused C2-Occipital (skull), so I need to be very careful to avoid the very jarring rides. That being said, I still would not have a problem with EE or Test Track. In WDW I would not ride BTMRR (though I still ride it, knowing that my neck is going to hurt for the rest of the day so I saved for last), definitely not Space Mountain.
Though this is a WDW thread, I live close to DL so I just wanted to give any other spinal fusion people a heads up to avoid the Matterhorn, although Space Mountain in DL is very smooth, as is California Screamin'.
When I ride TSM, I do what a PP suggested and looked down, kind of tuck my neck, whenever the ride car starts moving. The car is jerky, but it's a weird kind of side to side jerky.
Though I do not have a lower back fusion, I do have problems in that area as well as fibromyalgia, and what many people have reported as their biggest problem was continually needing to sit on hard benches, especially those with no backs. If it is at all possible I suggest carrying some kind of cushion for benches in shows and even some rides, wherever it is allowed. Continually having to sit on hard completely flat hard benches (which are usually shallower than a normal seat) really takes its toll on the lower back.
I have found that the very worst seats in the Park are in the Laugh Floor. even if you just put a sweatshirt under you on this seat, it will help.
