**4.3. Angle of trunk rotation**

The change in ATR was statistically significant. On average, the reduction was only 2.2°. This is less than that previously reported in AIS patients, which averaged 3–4<sup>o</sup> [20, 36]. The difference between our study and others may be related to the fact that their subjects were adolescents and had better spinal flexibility than the present cohort.

The difference in ATR when performing RAB in forward flexion between baseline and at ninth month was statistically very significant (*p* = 0.0023). After 9 months of home-based training, the ATR during RAB reduced from a mean of 9.3–7.3°. The decrease of 2° is consistent with the findings by Borysov and Borysov in much younger patients [20].

We are not aware of any study that measured the ATR changes in adult scoliosis patients after performing PSSE and are therefore unable to make any comparison.
