Relationships Between Spinal Curvature Parameters and Somatic Variables, Bone Mineral Density, Sedentary Habits and Physical Activity Levels in Young Adults: a Cross-Sectional Study

Background: Postural disorders in young adults result in poorer physical performance and quality of life in old age. It is important to know the determinants of posture parameters among the young adult population. Objectives: The aim of the study is to evaluate relationships between spinal curvature parameters and somatic variables, bone mineral density (BMD), sedentary habits and physical activity (PA) levels in young adults and to verify the influence of time spent passively on parameters of thoracic kyphosis (CT) and lumbar lordosis (LL). Material and methods: The study included adult Caucasian women and men of European origin aged 22.9±1.09 years. Computerised posture testing was carried out using the Zebris CMS10 (thoracic kyphosis angle (CT), lumbar lordosis angle (LL), lateral deviation (LI)). The angle of trunk rotation (ATR) was assessed via the Bunnell scoliometre. Bone mineral density (BMD) was also measured by densitometry using the NORLAND pDEXA apparatus, body composition by bioelectrical analysis with the TANITA BC 418 type analyser, physical activity level (PA) and sedentary lifestyle by questionnaire, and body mass index (BMI) as well as anthropometric measurements were taken. Results: Of all the analysed variables, the strongest relationships with posture parameters were found for PA and TK and LL, sit time for LL and LI; BMI for TK; and also FFM for LL and LI. Regardless of gender, the longer the average time spent sitting, the higher the risk of thoracic kyphosis disorders and the greater the risk of reduced lumbar lordosis. In women, an average sitting time of more than seven hours significantly increased the risk of hyperlordosis. Conclusion: A sedentary lifestyle and physical activity are important determinants of body posture in young adults. Long periods of sitting predispose the subjects to postural disorders.