When my back starts to get tight (this has been happening more often lately as my back pack gets heavier and heavier with books) I always turn to my favorite yoga flow. The following flow is called Surya Namaskara or "Sun Salutation" and can be practiced throughout many levels of physical fitness and is my "go to" quick flow for relief of back pain.
The Asana flow... Prayer, Sky Reaching, Standing Forward Bend, Flat Back, Plank, Four Limb Staff, Upward Dog, Downward Dog, High Lunge
More about the Flow:
This Sun Salutation generates heat to cleanse your body and mind. As a moving meditation, this flowing series of poses honors the light and life-sustaining energy of [the sun] as well as the life force within your own body. This salute to the sun gets your heart pumping, increases circulation and takes your body through a full range of motion, which gets you into a comfortable flow.
The standing poses ground you to the earth, build body awareness and help you find your center. Forward bend and halfway lift elongate your spine, stretch your hamstrings and cleanse your digestive system. Plank and four-limb staff poses engage the muscles in your arms, shoulders, chest and abdomen. Upward-facing dog stretches your upper body as it opens your chest and frees your breathing. Downward-facing dog works muscles in your entire body and calms your nervous system.
Read More on this pose at Livestrong
LIVE, BREATH, POSE, REPEAT. NAMASTE.