Muscle activation in pelvic anteversion and retroversion

Introduction: The inability to maintain good pelvic stability has been attributed to inefficient muscle coordination and deconditioning of the stabilizing muscles. Despite this, little is known about the role of the pelvic muscles in anteversion and retroversion movements. Objective: To compare the neuromuscular activity of the tensor fascia lata, gluteus medius, upper and lower portions of the gluteus maximus, and multifidus in pelvic anteversion and retroversion. Methods: The neuromuscular activity of 17 healthy young adults (aged 25.3 ± 4.6 years) was assessed during five repetitions of the pelvic anteversion and retroversion movements. The Vicon-Nexus system (10 cameras) was used for the kinematic analysis of the pelvis in the sagittal plane (anteversion and retroversion), and the TeleMyo DTS Desk Receiver electromyograph and the Myomuscle v. 3.8 software to measure neuromuscular activity. The paired samples t-test was used to compare muscle activity between pelvic anteversion and retroversion movements using the Statistica v.8 software with a significance level of p < 0.05. Results: The comparison of the movements showed greater muscle activity in the inferior gluteus maximus in retroversion and greater activity in the multifidus in pelvic anteversion. The upper portion of the gluteus maximus showed relevant activation in both movements. Conclusion: There was more pronounced activity of the lower portion of the gluteus maximus in retroversion, while the upper gluteus maximus showed relevant activation level in both movements. The multifidi were more active in retroversion.


Introduction
The transmission of ground reaction forces along the lower limbs and spine during dynamic tasks depends on good pelvic control, i.e., on an adequate stabilization capacity. Even though the trunk musculature plays an important role in this stability, inadequate control of the pelvis can affect the transmission of forces through the kinetic chain of the lower limbs, causing structural overload and dysfunction. 1,2 Pelvic stability is achieved when passive (bones, joints, and ligaments), active (muscles and fascia), and control (neural) systems work together. 3 There seems to be an adequate balance between pelvic girdle stability and mobility in healthy people, 4 with lumbar-pelvic stabilization failure seeming to be one of the main mechanisms associated with dysfunctional processes. 5 The inability to control pelvic anteversion can result in excessive lumbar lordosis and posterior trunk displacement, 2 which can increase lower back pain. 4 On the other hand, decreased pelvic anteversion was also observed in patients with low back and sacroiliac pain. 6 This phenomenon has been related to changes in the muscle activation pattern and deconditioning of the stabilizer muscles. 6 A study by Hungerford et al., 3 compared the stability of the pelvis in hip flexion between people with posterior pelvic pain and a control group, and concluded that excessive pelvic anteversion is indicative of failure of the stabilization mechanism and load transfer across the pelvis. These people showed decreased ability to resist vertical loads during weight-bearing exercise.
Complementarily, iliac retroversion seems to be a normal component for optimal pelvic stabilization. 3 The function of different portions of the gluteus maximus, gluteus medius, and tensor fascia lata muscles as the main triplanar muscles of the hip joint is already well

Type of study and ethical aspects
This was a cross-sectional and exploratory study, part of an integrative project that investigated the kinematics of unilateral squat, of a sample of asymptomatic and

Study participants
The study included 17 asymptomatic and active

Data analysis
The data obtained from the kinematic analysis were   16 Its main anatomical action is to extend the hips, but during locomotion it can provide weight support, propulsion, and trunk forward inclination control. 16 The results of the present study indicate greater LGMax activity in retroversion, indicating its role in LGMax played a greater extensor role. This finding suggests that GMax upper and lower fibers should be considered separately by the clinical area and may explain the findings of the present study.
With the torso fixed, the hip extensors work in conjunction with the abdominal muscles to retrovert the pelvis. 4 Thus, excessive anteversion of the pelvis can occur due to GMax weakness or activation delay during hip extension. 9, 19 Although the trunk musculature plays an important role in stabilizing the spine, these muscles are not expected to prevent compensatory trunk movements due to poor control of the pelvis. Therefore, pelvis stability is important to protect the joints of both the knee and the lower back during gait. 2 The study by Takaki  Similar muscle activation levels were observed for TFL, GMed, and UGMax between movements. Greater muscle activity was observed for LGMax in retroversion and for both MFs in pelvic anteversion ( Table 1).
The results showed greater LGMax activity in retroversion and greater multifidus activity in anteversion.
GMed and TFL showed a low and similar activation level in anteversion and retroversion. The UGMax showed According to Powers,2 although GMed helps in the extension and external rotation of the hip, its contribution to these movements is not significant.
TFL also showed no activity differences between the movements performed. Imbalanced muscle activation,

Conclusion
LGMax activity was more significant in retroversion, while the MF was more active in pelvic anteversion. However, even these three muscles presented greater activation than that observed at baseline throughout the movement. Thus, it was decided not to analyze aspects related to the pattern of muscle recruitment.
Additionally, the data reported in this research should not be extrapolated to patient populations, considering that only healthy participants were analyzed. Finally, the LGMax is being overly recruited. In addition, the substantial UGMax recruitment indicates the role of a pelvic stabilizer, and could thus be an important muscle to be evaluated in cases where adequate lumbar-pelvic control is difficult in functional movements.