A sore back can be an incredibly debilitating injury. Depending on its severity, the injury can range from just a simple annoyance to something that will keep you from getting out of bed and moving. Stretching out your back can really help you and make it feel better. It will also promote muscle strengthening and make for a faster healing process.
Warm it up first. Stretching cold (and injured) muscles can be difficult and is not always the best idea. So before you just go out and stretch your back, warm it up first. Of course a warm up doesn't mean a jog or lifting weights. Try running in place for a mimute or two, or swing your arms from side to side by rotating your hips. Get the blood flowing and the heart pumping.
Move it around a little. The first way to stretch the back out is to just sort of tweak it a little with your own, somewhat natural movements. Do things like bending over, or moving your torso side-to-side. Actions like that will begin to loosen it up a little for more intense stretching. Also, this sort of movement will begin to give you an idea of just how sore your back really is and maybe how much stretching or activity it will able to handle for the time being. If the simple movements you do cause you a great deal of pain or seem to be incredibly stressful on your back, maybe today is not the day to push yourself. On the other hand, if everything feels good, then maybe it's time to take it to the next level.
Find a wall. Go and stand next to a wall, about six inches to a foot away from it. Place your hands against the wall up above your head. You should be facing the wall. Lean toward the wall with your body, keeping your feet and your hands in place. You will be bending your body so that it looks a bit like a banana. This stretching motion, with your hands above your head, is a great way to loosen up your entire back. It is especially good for your lats and the middle area of your back, which is also a difficult place to stretch. Don't lean in to far and tweak the way this stretch is done to fit your own needs. If leaning to one side or the other feels better, then do that. Either way, take it easy and hold the stretch for at least 10 to 15 seconds. Do both sides of your back and move your body to stretch laterally.
Get down on the ground. Lie down on your back and bring your knees all the way up as far as you can toward you chest. Hug them with your arms. Once you are in this position, roll back and forth along your back. As your body rolls with your legs and arms tucked in, your back will get a nice stretch. You do not want to roll too fast. Though it will be difficult to control without any arms or legs, try your best to slow your self down by how you lean your body and try to stretch the areas that you need to most.
Stretch the rest of your body. In all honesty, the back is the gateway between the upper and lower half of your body. If you stretch your back well, but have not loosened up your legs, you still won't feel very good. So sit down and stretch out your hamstrings, quads and calves. Stretch everything you need to so that the rest of your body is prepared to help your back out as much as possible.