Most back pain is due to faulty posture, the posture in which you probably spend most of your days, contributes to weak abdominal and spinal muscles.
Not only do most of the Pilates exercises strengthen the muscles necessary to properly support the spine, the movements bring an awareness about what proper posture actually is. To see a change in your posture and to heal your back pain, it's neccessary to incorporate the Pilates Principles into your daily life. Lengthening the spine and holding neutral spine and pelvis while you stand in line at the grocery store, sit straight up on your sit bones, spine long with the abs engaged (not sucked in for dear life but not hanging over your waistband, thank you very much), when at your desk or in the car. If you can incorporate the deeper Pilates concepts into your daily life, you'll notice changes immediately - in your back pain, in your posture, and ultimately, in Joseph's words "live your life with spontaneous zest and pleasure". After all, isn't that what being healthy and fit is about?