The ability to adopt the appropriately corrected body posture is one of the factors that determines the effectiveness of therapeutic programmes. This study determined the active self-correction expressed by the change of sagittal spinal curvatures (in standing and sitting positions) in 249 children (136 females, 113 males, aged 10-14 years) instructed with ‘straighten your back’ command (SYB). Spinal curvatures (sacral slope-SS, lumbar lordosis-LL, global, lower and upper thoracic kyphosis-TK, LK, UK, respectively) were assessed using Saunders inclinometer. The assessment was done in spontaneous standing and sitting positions and in the positions adopted following the SYB. In a standing position SYB led to the significant (P<0.001) increase in SS, and the significant (P<0.01) reduction in LL, TK, LK, UK. In a sitting position SYB resulted in significant changes (P<0.001) from kyphotic to lordotic position of SS and LL and to the significant (P<0.001) reduction of TK (36.5°±10.8 vs. 23.5°±11) and the flattening of LK (15.2°±8.7 vs. 1.0°±8.4). There were gender-based discrepancy with regards to active self-correction only for LL in a standing and UK in a sitting position. Females exhibited a significant reduction in LL (P<0.001). UK significantly increased only in males (P<0.001).
The 'straighten your back' command leads to moving the spine away from mid-range towards end range of motion. Therefore, the command should not be used to elicit the most optimal back posture. Additional studies are necessary to determine if the active self-correction is different in females and males.