Correlation analysis of hip rotation ratio and trunk stabilizing muscles

Objective: Hip rotation is crucial forwaist and pelvic rotation. However, the correlation between the hip rotation ratio and the activation of the trunk-stabilizing muscles remains unclear. Design: Cross-sectional study. Methods: This study included 30 healthy male and female participants from K University. To investigate the correlation between trunk stabilization muscle activation and hip joint rotation, we measured the activationof the erector spinae, internal oblique, external oblique, and gluteus medius muscles using surface electromyography (sEMG). Range of motion (ROM) of hip joint rotation was evaluated using a goniometer. Results: A significant correlation was identified between the hip internal rotation ratio and the activation of the erector spinae and internal oblique muscles (p < 0.05). However, no significant correlation was found between the hip external rotation ratio and trunk-stabilizing muscle activation (p > 0.05). Additionally, a significant correlation was observed amongthe erector spinae, internal oblique, external oblique, and gluteus medius (p < 0.05). Conclusions: Hip internal rotation is correlated with the activationof the erector spinae and internal oblique muscles. Therefore, assessing and addressing the left/right ratio of hip internal rotation and trunk stabilization muscles may be essential for maintaining trunk stability and ensuring symmetry in hip joint internal rotation ROM.