Associations Between Rhythmic Gymnastics Training History and Sagittal and Frontal Spinal Alignment: A Preliminary, Cross-Sectional Study

Abstract

Objectives: This exploratory cross-sectional study examined the associations between rhythmic gymnastics training history and sagittal and frontal spinal alignment. Methods: Twenty-eight female volunteers were divided into a rhythmic gymnastics group (n = 14; comprising six registered and eight nonregistered rhythmic gymnasts) and a sedentary control group (n = 14). Spinal curvatures were assessed non-invasively using the Idiag SpinalMouse® system. Results: Independent-samples t-tests indicated that rhythmic gymnasts exhibited significantly lower thoracic kyphosis (p = 0.002, Cohen’s d = 1.32), lumbar lordosis (p = 0.003, Cohen’s d = 1.24) and trunk inclination (p < 0.001, Cohen’s d = 1.91), alongside greater sacral inclination (p < 0.001, Cohen’s d = −1.64) and increased lumbar Cobb angles (p = 0.008, Cohen’s d = −1.17), compared to the sedentary controls. Subgroup analyses revealed that registered rhythmic gymnasts demonstrated significant deviations across all sagittal-plane parameters and no differences in frontal-plane parameters, whereas nonregistered rhythmic gymnasts displayed significant differences in trunk inclination and lumbar Cobb angle in comparison with the sedentary controls. The two rhythmic gymnastics subgroups showed a significant difference only in thoracic kyphosis (p = 0.002). Simple linear regression analysis identified that years of training emerged as a significant predictor of thoracic kyphosis (R2 = 0.638, slope = −1.76, p = 0.001) and trunk inclination angle (R2 = 0.369, slope = 0.16, p = 0.021). Conclusions: Long-term rhythmic gymnastics training is associated with multi-planar spinal alignment variations, particularly sagittal flattening and increased frontal asymmetry. While these non-invasive quantitative findings provide an exploratory baseline, longitudinal investigations incorporating objective load monitoring and diagnostic imaging are required to determine whether these alignment profiles represent benign performance-related adaptations or early precursors to spinal pathology.