Analysis of sagittal spinal alignment at the adolescent age: for furniture design

Abstract

Knowledge of the parameters of the human spine is essential in designing ergonomic furniture. The purpose of this study was to evaluate spinal alignment in adolescents of various ages. The lengths, curvatures, and concave–convex spacings of the spine were investigated in 268 participants aged 9–18 years. Ten ages were classified, and the rate of increase of parameters was calculated for each age and age group. The results showed that spinal parameters, except for cervical lordosis, increased with age. Adolescents were classified as 9–10, 11–12, 13–15, and 16–18 years old. A rapid increment of lengths and concave–convex spacings occurred at ages 13–15, while that of curvatures occurred at ages 16–18. Spinal parameters differed significantly among the age groups (p < 0.05). Concave–convex spacings reflected differences in the spine more clearly than the other parameters. This study suggests the necessity of designing spine-related furniture based on spinal parameters, thus providing adaptive support for the adolescent spine, particularly the lumbar spine. Practitioner summary: This study examined spinal lengths, curvatures, and concave–convex spacings in adolescents aged 9–8 years and then divided them into four age groups. Concave–convex spacings effectively reflected spinal differences between age groups, particularly the lumbar spine. These results can inform the ergonomic design of spine-related furniture. HIGHLIGHTS Spinal parameters increased progressively between 9 and 18 years. Regression analysis showed good linear correlations between TK, LL, SK, TS, and LS with age. Age classification of adolescents was Group I (9–10 years), Group II (11–12 years), Group III (13–15 years), and Group IV (16–18 years). The rapid increment of lengths and concave–convex spacings were in Group III while that of curvatures were in Group IV. Concave–convex spacings were vital parameters to evaluate the global balance of the spine. The lumbar spine is an essential segment for characterizing spinal alignment.