## 4 Discussion
This difference in the measurement techniques and the focus on dynamic vs. static analysis likely explains the contradictory results. Pelvic retroversion, in addition to increasing acetabular anteversion, also resulted in increased hip extension. [PERSON] et al. (2017) [27] demonstrated that subjects with kyphosis attempted to maintain an upright position and walk using compensatory mechanisms, such as pelvic retroversion (>20\({}^{\circ}\)), leading to hip hyperextension. Subjects with retroversion had a hip extension of \(-6.9^{\circ}\pm 5.9^{\circ}\), while those without retroversion had \(-4.5^{\circ}\pm 8.5^{\circ}\). The finding that subjects with pelvic retroversion had a hip extension of \(-6.9^{\circ}\pm 5.9^{\circ}\) has important clinical implications. Increased hip extension due to pelvic retroversion can lead to altered biomechanics, particularly during walking and weight-bearing activities. This compensatory mechanism might help maintain balance and posture, especially in individuals with spinal misalignment or kyphosis. However, this increased extension may also place added stress on the hip joint, potentially contributing to joint degeneration or discomfort over time. From a rehabilitation perspective, understanding these biomechanical changes is crucial for developing effective treatment plans. For example, therapies should focus on improving pelvic alignment and hip mobility to reduce compensatory movements, which could otherwise exacerbate joint stress. Strengthening exercises for the hip extensors, along with postural correction strategies, may help alleviate symptoms and improve overall function in patients with pelvic retroversion. Manual therapy and gait retraining may also be employed to address the altered movement patterns caused by this hip extension. Furthermore, the studies analyzed indicate that pelvic incidence (PI) is a crucial morphological parameter that regulates sagittal balance and influences spinal and hip positional parameters. Sagittal imbalance, due to increased spinal kyphosis or posterior pelvic tilt, is a critical factor affecting the quality of life. [PERSON] et al. (2015) [47] highlighted that retroverted hip orientation can cause conflicts between the femoral neck and the anterior acetabulum, limiting ROM, especially during rotational activities. The close proximity of the hip to the lumbopelvic region can predispose the lumbar area to excessive rotational forces when the proximal regions compensate for limited hip rotation. Regional interdependence between the lumbopelvic region and the hip is crucial for assessing excessive compensatory strategies. The second group of studies examined the effect of femoral neck torsion on hip adaptation in the three spatial planes. Three studies demonstrated that increased femoral anteversion leads to more pronounced internal hip rotation during gait, decreased abductor lever arms, and increased contact forces. [PERSON] et al. (2021) [48] evaluated the effect of femoral torsion alone on hip loads, excluding parameters such as acetabular coverage, acetabular retroversion, and joint deformities. With increased femoral anteversion, a compensatory internal hip rotation (20\({}^{\circ}\)) occurred during the transition from stance to swing phases to restore abductor lever arms and stabilize the joint during dynamic movements. [PERSON] et al. (2018) [49] confirmed that internal hip rotation during gait ranges from 2.8\({}^{\circ}\) to 11.8\({}^{\circ}\), present throughout the stance phase and during mid-to-terminal swing phases. This study correlated femoral anteversion of 15.7\({}^{\circ}\pm 6.3^{\circ}\) with static internal hip rotation. Subjects with greater internal hip rotation in standing (\(\geq\)11.3\({}^{\circ}\)) exhibited greater internal rotation during gait. [PERSON] et al. [49] (2018) demonstrated that femoral anteversion leads to increased internal hip rotation during dynamic activities, which is particularly relevant in the context of symptomatic patients.