Get yourself a foam roller and loosen up those back muscles with this simple self massage:
Lay with your back flat on the floor and your feet shoulder width apart. Place your foam roller on the mid part of the back. (right under your shoulder blades) Move your body up and down, towards and away from your feet, to massage your back and loosen up those trigger points.
Lower yourself onto the floor, extending your right leg out in front of you, and bend your left knee so that your lower leg is behind you. Place the end of a foam roller beneath your upper right hamstring, just below the glutes, and place your hands on the foam roller on either side of your leg. Roll your upper hamstring just enough so that your foot flexes down, and roll it back again, for 30 to 60 seconds; switch sides and repeat.
With your feet flat on the floor, slightly wider than shoulder-width, center a foam roller beneath your glutes. Lift your right leg and rest your right ankle on your left knee. Roll back and forth from the center of your right glute to the bottom of your spine for 30 to 60 seconds; switch legs and repeat.