Background: The erector spinae is more resistant to fatigue in adult women than men. However, no study has reported the sex differences in back muscle fatigue in children.
Objective: The aim of this study was to evaluate the fatigability of erector spinae in prepubertal children and adults, in both males and females.
Methods: Fourteen prepubertal boys, 13 prepubertal girls, 14 adult men, and 13 adult women performed the Sørensen back isometric endurance test until exhaustion. The results of electromyographic (EMG) power spectral analysis of erector spinae were compared between both age groups and sexes.
Results: The slopes of EMG power spectral median and mean power frequency were significantly higher in males than in females, in both age groups. Furthermore, the slopes were significantly lower in prepubertal children than in adults, in both males and females.
Conclusions: Our results showed major differences in the fatigue threshold of the erector spinae between boys and girls and children and adults. The muscle fatigued faster in prepubertal boys and adult men than in prepubertal girls and adult women. In both sexes, a lower slope of EMG power spectrum parameters of the erector spinae was noted during endurance test in prepubertal children compared to adults.
Keywords: Electromyography; children; erector spinae muscle; muscle fatigue; prepubertal; sex difference.