A clinical postural model of sagittal alignment in young adolescents before age at peak height velocity

From a clinical point of view, knowledge of customary standing positions among healthy young adolescents is of primary importance. The purpose of this study was to document the correlations between sagittal standing posture parameters in a pre-peak height velocity (pre-PHV) cohort. This cohort study included 639 pre-PHV boys (age 12.6 [SD, 0.54] years) and 557 pre-PHV girls (age 10.6 [SD, 0.47] years). Gross body segment orientations and spinopelvic orientation/shape indexes were quantified using a clinical screening protocol. Pearson's correlation coefficients were determined for all sagittal standing plane alignment parameters, and a postural model was used to analyze the correlations between parameters. Both at the gross body segment and spinopelvic level, an interdependence was found between postural parameters. No correlations were observed between 'global' parameters related to the pelvis, trunk or body anteroposterior translation postures and 'local' spinopelvic geometries. A similar pattern and strength of correlations was obtained in pre-PHV boys and girls, except for the reciprocal relationships between the craniovertebral angle and adjacent anatomic segment characteristics and between thoraco-lumbar geometries. Although the correlation schemes do not imply a causal relationship, the proposed postural model allows conjecture about standing posture to be organized slightly differently in pre-PHV boys and girls. Whereas the standing posture in pre-PHV boys might be organized predominantly according to an ascending mode, bottom-up and top-down organizations appear to coexist in pre-PHV girls.