You should not have to bend down to look at the terminal. In many cases, you will have to elevate the terminal to accomplish this. Take occasional breaks from the computer use to stretch. It does help by keeping your back straight. Remember the idea is to keep the posture straight.
Many people tend to sit stopped or bend that put lot of pressure on their spine and back.
Sitting Most people spend long hours sitting. Make sure your chair correctly supports your body. A good chair bottom supports your hips comfortably but doesn't touch the backs of your knees. Very low chairs can be uncomfortable and difficult to get in and out of, as can chairs without arms. Your feet should rest flat on the floor.