## 4 Discussion  
Significant kinematic differences were found between injured and non-injured runners as exhibited by their GPS score. Not all gait kinematic changes expressed by the GDI differed. The total GPS score detected differences between both groups. The sum of all GDI's differences, significant or not found during the gait cycle, indicated differences in the total GPS score, implying that the GPS score was capable of kinematic discrimination between the injured and non-injured runners' groups. The motion of the pelvis was found to be relatively the same in both groups, contrary to [PERSON] et al. who argued that injured  
Figure 3: Pelvis and lower limb kinematics of injured and non-injured running groups: injured group; left in red, right in blue. Non-injured group in grey. runners with PFPS might present with a more backward trunk lean [25], and thus, we would expect to find differences in the sagittal plane pelvic tilt. Our findings did not correlate with previous studies where pelvic obliquity was a significant contributing factor to running injuries [15; 20]. [PERSON] et al. found that a contralateral pelvic drop correlated with PFPS [20]. In another systematic review, the authors found that female runners with ITBS increased their peak trunk ipsilateral during stance [15]. In our study, pelvic obliquity was not a contributing factor. Pelvic rotation differed between the groups, with higher GDI values that had not been previously documented, but the excessive pelvic rotation can be explained as a strategy to increase step length [31] or as weaker muscular support leading to poor pelvic rotational control by the injured runners. Hip adduction was found to have higher GDI values only on the left, however, hip rotation presented with higher values on both sides. These findings correlate with previous studies emphasizing the role of hip adduction and rotation in running injuries [15; 20; 24; 31]. [PERSON] et al. in their cross-sectional study of mixed sex cohorts found moderate evidence supporting a correlation between PFPS during running and increased hip adduction and internal rotation [20]. However, they found very limited prospective evidence that increased hip adduction is a risk factor for PFPS in female runners or that running retraining changes symptoms and function in runners [20]. [PERSON] and [PERSON] [15] concluded in their systematic review that female runners who developed ITBS presented with increased peak hip adduction and increased peak knee internal rotation during stance. A systemic literature review study aimed at identifying the biomechanical variables involved in the etiology of ITBS [32]. The authors demonstrated that runners with a history of ITBS appear to exhibit decreased hip adduction angles at heel strike while exhibiting decreased total abduction/adduction ROM at the hip during stance phase. They concluded that greater internal rotation of the knee joint and increased hip adduction angles, may play a role in the etiology of ITBS. These findings support [PERSON] et al. 's conclusions who emphasized addressing the motor program in order to change the motor pattern, including excessive hip adduction, by using biofeedback training in treating patellofemoral pain [25]. In our study, we found that GDI values differed in the sagittal plane and were higher amongst the injured group in right knee flexion/extension, and left ankle dorsi/plantar flexion. These findings suggest that sagittal plane kinematics might also be a contributing factor to running injuries. Generally, sagittal plane deviations are unrelated to running injuries. Our findings correlate with two studies that also found significant associations between PFPS and sagittal plane deviations, reduced stance phase peak hip flexion [20; 33]. However, according to the GDI values in our study, we cannot identify the specific running phase at which the deviation occurred. Foot rotation is determined by the rotational profile of the lower limb and foot pronation/supination movement [34].