INTRODUCTION: There is a lack of data in the literature for determining the influences of the extensor portion of the gluteus maximus muscle on pelvic tilting and, thus, on lumbar stability. OBJECTIVES: To assess the influences of the extensor portion of the gluteus maximus muscle on pelvic tilt. METHODS: Ten healthy young subjects were recruited, with a body mass index (BMI) below 24.9 kg/m² and leg length discrepancy below 1 cm. The BMI, pelvic perimeter and lower-limb lengths were assessed and, subsequently, the degrees of hemi-pelvic tilt and asymmetry between them were analyzed using lateral view photographs of the subjects in a standing position, using SAPO (Software for Postural Assessment). Next, fatigue was induced in the extensor portion of the gluteus maximus muscle on the dominant side, and after that the hemi-pelvic tilt and the asymmetry between the hemi-pelvises were reassessed. The Pearson r and Student t tests were conducted at the significance level of α=0.05. RESULTS: There were no significant correlations between the confounding variables and asymmetry of the hemi-pelvic angles. There were significant changes in the hemi-pelvic angle of the dominant side (t=3.760; p=0.004). CONCLUSIONS: Fatigue in the extensor portion of the gluteus maximus muscle can generate increases in the tilt angle of the ipsilateral pelvis.
gluteus maximus; fatigue; pelvic tilt
