## 4 Discussion  
The objective of this study was to examine how pelvic tilt and femoral torsion affect hip biomechanics. The main findings showed that pelvic retroversion increases acetabular anteversion and hip extension, while femoral anteversion significantly influences internal hip rotation during gait. These results highlight the importance of biomechanical interactions for improving clinical assessments and treatments. This review highlights the main factors for each group of studies presented. The first group of studies made it possible to observe the effect of pelvic tilt (or associated parameters) on acetabular anteversion and hip mobility. The results indicate that pelvic retroversion increases acetabular anteversion and hip extension. The differing interpretations arise from methodological and population differences between the studies. [PERSON] et al. (2021) (2021) found no correlation likely due to analyzing static conditions, while [PERSON] et al. (2004) (2004), under dynamic conditions, observed a linear relationship between pelvic retroversion and acetabular anteversion. This review integrates both results, suggesting that pelvic retroversion can influence acetabular anteversion and hip mobility, though the extent may depend on the conditions studied. This is relevant because acetabular orientation is considered a key morphological feature in determining acetabular function and symptoms. However, the effect of pelvic tilt on acetabular orientation remains under-investigated and contentious. The conflicting results between [PERSON] et al. (2021) (2021) and [PERSON] et al. (2004) (2004) regarding the effect of pelvic retroversion on acetabular anteversion can be attributed to differences in methodology and population. [PERSON]'s study used 3D reconstructions of CT scans focusing on ideal pelvic planes, which might not fully represent dynamic functional movement. In contrast, [PERSON] analyzed various pelvic inclinations under real-life conditions, providing more dynamic insights. Additionally, [PERSON]'s study involved a younger, asymptomatic population, while [PERSON]'s included older individuals and cadaveric samples, highlighting how population differences might affect outcomes. Notably, two studies presented differing results: [PERSON] et al. (2021) (2021) found no significant correlation between pelvic tilt and acetabular anteversion, while [PERSON] et al. (2004) (2004) confirmed that increasing pelvic retroversion linearly increased acetabular anteversion. The divergence in results may have been due to the first study analyzing pelvic morphological parameters (PI) on an ideal plane not reflecting the real plane, whereas the second study assessed acetabular anteversion variations at the caudal, central, and cranial levels in four different dorsoventral pelvic inclination positions, providing more clinically relevant insights. The mean anteversions at the 0\({}^{\circ}\), 20\({}^{\circ}\), 40\({}^{\circ}\), and 60\({}^{\circ}\) sacral gradients were:  
Caudal anteversions: 52\({}^{\circ}\), 48\({}^{\circ}\), 31\({}^{\circ}\), and 15\({}^{\circ}\). Central anteversions: 45\({}^{\circ}\), 36\({}^{\circ}\), 26\({}^{\circ}\), and 11\({}^{\circ}\). Cranial anteversions: 44\({}^{\circ}\), 39\({}^{\circ}\), 26\({}^{\circ}\), and 2\({}^{\circ}\). The discrepancy between the findings of [PERSON] et al. (2021) (2021) and [PERSON] et al. (2004) (2004) regarding the relationship between pelvic tilt and acetabular anteversion can be explained by methodological differences. [PERSON]'s study used CT scans and 3D reconstructions to analyze pelvic incidence in static conditions, which may not fully capture the dynamic nature of pelvic movement. In contrast, [PERSON]'s approach assessed acetabular-anteverson across different sacral gradients (0\({}^{\circ}\), 20\({}^{\circ}\), 40\({}^{\circ}\), 60\({}^{\circ}\)), providing more clinically relevant insights by accounting for varying dorsoventral pelvic inclinations.