Isokinetic trunk muscle performance in adolescents with different body mass indices

Objective: This study aims to evaluate the isokinetic performance for the peak torque and average power of the spinal flexor and extensor muscles in adolescents aged 12 to 18 years. The study also analyses the differences between the trunk muscle peak torque and average power with body mass index (BMI). Method: The peak torque and average power of the trunk flexor and extensor muscles were measured in 180 adolescents (aged 12-18 years). The participants were classified into four groups according to BMI. The Biodex isokinetic dynamometer in concentric mode at speeds of 60 degrees and 120 degrees/sec was used for assessment. Results: One-way multivariate analysis of variance MANOVA results demonstrated a significant difference in trunk muscle peak torque and average power with different BMI (F = 14.692, p = 0.0005). A Pearson's correlation analysis demonstrated a significantly negative correlation between weight and peak torque of trunk flexors and extensors (r = - 0.43, p = 0.0001; r = -0.31, p = 0.007, respectively). Finally, the results showed a negative correlation between weight and average power of trunk flexors and extensors (r = -0.54, p =0.0001: r = -0.31, p = 0.007). Conclusion: In this study, overweight and obese adolescents are found to be correlated with decreased trunk muscle torque and power. Thus, therapeutic interventions for overweight and obese adolescents, along with exercise training programmes, may help improve muscle performance including peak torque and power. Finally, these measures may enhance the quality of life of such adolescents.