Exploring the influence of body composition on trunk stability: Insights from a male demographic study

Objective: To find body mass index (BMI) association with trunk stability, core muscles activation, trunk extensor muscles endurance and balance among males. Methods: Cross-sectional study design on 153 males (mean age: 33±7 years, mean BMI: 27.4 ± 3.9 kg/m^2) who underwent assessments for trunk stability (modified double straight leg lowering test), core muscles activation (electromyography analysis), trunk extensor muscles endurance (Biering-Sorenson test), and balance (limits of stability and total stability index). Results: Correlation analysis revealed associations between BMI and these measures, as well as waist circumference (WC) and waist-to-hip ratio (WHR). BMI exhibited significant negative correlations with trunk stability (r =-0.80), core muscles activation [transverse abdominis (r =-0.39) and multifidus (r =-0.50)], trunk extensor muscles endurance (r =-0.98) and balance (r =-0.76). WC and WHR also showed negative correlations with trunk stability (r =-0.79 and r =-0.70, respectively). Conclusions: Across BMI categories including normal, overweight, and obesity class I, high negative correlations were observed with trunk stability and trunk extensor muscles endurance, moderate negative correlation with balance and low negative correlation with core muscles activation. Trunk stability and core muscles activation revealed a positive relationship demonstrating the significance of core muscles in spinal control. The study findings recommend body composition indicators and MDSLL test as convenient measures to identify males with risks of developing low back pain and the importance of initiating core strengthening exercise program to improve core muscles activation.