The difference of whole-body sagittal alignment in different postures in young, healthy adults

Abstract Study DesignProspective study.ObjectiveTo identify the differences of radiographic between standard upright position and natural and comfortable upright position.MethodsRadiographic parameters of 50 young and healthy adults were evaluated including the global cervical angle (GCA), global thoracic angle (GTA), global lumbar angle (GLA), which were used to depict the spine profile; the distance from the cranial sagittal vertical axis (CSVA) to the posterior corner of S1(CSVA-S), the center of the hip(CSVA-H), the center of the knee(CSVA-K) and the ankle(CSVA-A), respectively in both upright positions and natural and comfortable upright position, which were employed to describe the whole-body balance.ResultsSignificant differences could be observed in all the GCA(17.39 ± 6.90 vs. 10.90 ± 3.77, p < .001), GTA(25.63 ± 7.27 vs. 45.42 ± 8.15 p < .001), GLA(42.64 ± 8.05 vs. 20.21 ± 7.47 p < .001), CSVA-S(0.33 ± 2.76 cm vs. 8.54 ± 3.78 cm, p < 0.001), CSVA-H(1.53 ± 3.11 cm vs. 5.71 ± 3.26 cm, p < 0.001), CSVA-K(3.58 ± 2.47 cm vs. 5.22 ± 2.69 cm, p = 0.002) and CSVA-A(1.79 ± 1.92 cm vs. 4.79 ± 2.51 cm, p < 0.001) in the two different standing postures, respectively. Compared with standard upright position, natural and comfortable upright position results in a more kyphotic spine profile.ConclusionSignificant differences in sagittal radiographic parameters were found between the standard upright position and natural and comfortable upright position, with the latter revealing a more kyphotic spinal profile more common in everyday life, which may explain the existing spinal pathologies as well as predict postoperative complications. The natural and comfortable upright position should be a factor to consider when performing a surgical plan.