Trunk flexor and extensor muscle strength capacity in healthy ındividuals

Abstract

Objective: Generating reference values of trunk muscle strength is of value for specific age groups and gender in every society. The aim of this study was to define flexor and extensor muscle strength of the trunk and the flexion/extension ratio in healthy individuals. Materials and Methods: Hundred and two healthy individuals were included in this study. Isokinetic concentric strength of trunk flexor (Flex) and extensor (Ext) muscles of the participants were measured via an isokinetic dynamometer. Tests were performed at speeds of 60°/s and 180°/s. Maximum strength was characterized with peak torque (PT) (Flexabs, Extabs; N·m), peak torque normalized to body weight (PTNBW) (Flexnorm, Extnorm; N·m·kgbw-1), and Flexabs/Extabs ratio. Results: For angular velocity of 600/s, PT and PTNBW of flex and ext strength were higher in men; while for angular velocity of 1800/s, PTNBW of flex and ext strength were higher in women (p<0.05). Extensor strength for 600/s and 1800/s angular velocities yielded lower values than flexor strength in both genders. The Flexabs/Extabs ratios were 1.67±0.62 for 600/s and 4.93±4.60 for 1800/s. Conclusion: Trunk extensor strength was higher than flexor strength in men and women at 600/s and 1800/s angular velocities. In this study, the ratio of Flexabs/Extabs was not within the accepted range in non-active adults and there was no difference between men and women, indicating that muscle strength is not sufficient in this population. The data of this study can be used as a comparison parameter in future studies to get normative data, or common values in healthy individuals aged 18-30.