Regularly a flat back is found in patients with idiopathic scoliosis. This is only one part of the three-dimensional deformity, however many physiotherapists first try to influence this sagittal deformity before treating vertebral rotation and lateral deformity. As can be seen in literature, forced mobilizations of flexion may lead to an increased progression rate in patients with idiopathic scoliosis before the end of growth. This may be due to the fact, that a flat back as a structural component of scoliosis may stabilize scoliosis itself in a secondary manner. Slight mobilizations, however, seem to be useful. The purpose of this study was to assess the influence of specific exercises in combination with rotational breathing (Schroth) on sagittal breathing excursions. 1335 scoliosis patients have been assessed with the help of a measuring device. The sagittal breathing excursion was measured at the height of manubrium/corpus sterni and the processus xyphoidus/corpus sterni. Sagittal breathing expansion increased highly significant from 1.5 to 1.77 cm in the upper region and from 1.35 to 1.90 cm in the lower region (p < 0.001). We may conclude, that specific exercises including rotational breathing (Schroth) can partly correct the flat back deformity. A slight mobilization of flexion does not support curve progression, as it has been shown in literature. Those exercises may retard curve progression.