Your hunting situation (as well as being careful with your back) whould dictate how high you should climb. I like to be just a couple of feet over the vegitation/brush that I need to shoot over. For example, one of my stands (60-70 yards off some very well used travel corridors) is only about 10 ft. off the ground because the surrounding ground cover is approx. 4-5 ft. This height provides me a great shooting angle to the travel paths I'm watching over. Yet there are a couple of spots that are up a ridge and overlook a swampy area that the deer travel around. For this spot I prefer using a ground blind (have used both pop up as well as making a blind from the natural ground material around. I actually prefer using a variety of options for each give that little bit different hunting experience. It is so cool when a deer travels right under the tree you're sitting in but as cool is having a deer pass by close while you're in a ground blind. If your hunting situation will allow you to use ground blinds and having a messed up back, I would stay as close to earth as the situation will allow. Good luck and be safe.