The spine supports the body. The natural curves and discs absorb shock and allow the body to move normally. When the spine is in the natural S shape the weight of the body is supported correctly, movement is easier and wear and tear on the back is reduced.
The modern lifestyle of most people puts pressure onto the spine due to long periods of sitting, either at work, travel or watching television, leading to such conditions as lower back pain and rounded shoulders. Pilates helps to re-align the spine by strengthening and lengthening specific muscles which support the spinal column.
If practiced regularly, Pilates not only improves your posture making you stand straighter and taller, but it also works muscles in the legs, bottom, abdominals and upper body. So in addition to the health benefits achieved from having great posture, you will also improve the muscle tone throughout your body therefore improving your overall shape.