Active self-correction of back posture in children instructed with 'straighten your back' command.

The ability to adopt the properly corrected body posture is one of the factors determining 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 after the SYB. In a standing position SYB led to the significant (P < 0.001) increase in SS, and the significant (P < 0.01) decrease in LL, TK, LK, UK. In a sitting position SYB led to 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 regarding active self-correction only for LL in a standing and UK in a sitting position. Females demonstrated a significant decrease 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. Further studies are needed to determine if the active self-correction is different in females and males.