I love my Gazelle as it seems to be the most effective means of aerobic exercise without the impact on my joints. You set your own pace on it and you control the stride, I have low back issues as well and it seems for me to not be an issue. For me it seems to not only loosen the low back muscles it helps with my breathing and my ability to speak. I was so deconditioned from my week stay at the hospital that it was all I could do to step on a treadmill and to walk at a 2 MPH pace--I just could not manage that, but I was able to manage the 10 minutes on the gazelle and found it helped with my choking sensation. I felt better while on it than stinging a chair!
After a very short time they will squeak, so it will be annoying to others. I just ignore the squeak and put headphones on and listen to some music, I used to watch TV when I had it in the living room. In the summer I put it on my porch and let my neighbors listen to my squeak, they smile and nod their heads of approval of my exercise efforts. For me this is the best form of exercise and until I can walk outside without the air being cold it will be my only form of exercise.
If you are thinking of one I would suggest checking yard sales and estate sales, my current one was a 20.00 estate sale find. You do not need the Hydraulic resistance set up if you are concerned about your back (if you get one with it you do not need to use it--just saying save your money and go for the basic model if it is a choice) 1235 days ago