# Application of the Gait Kinematics Index in Patients with Cerebral Palsy
## 4 Discussion  
Gait indices, such as the Gait Index and the Gait Deviation Index, are used clinically to assess patients' gait quality. There is a need for the development of further gait indices to better understand the complexity of movement and to match therapies to individual patients' needs, which can contribute to more effective rehabilitation and improved quality of life. The GKI is one of the new gait indicators that have been proposed, but it has not yet been evaluated for clinical use. The main objective of this study was to assess the clinical utility of the GKI in the population of patients with CP. The possibilities of the application of the GKI to the group of patients with CP were assessed on the basis of the correlation of its results with the GGI and GDI values. In addition, the distribution of the GKI values was evaluated in terms of the CP type and method of treatment. The results obtained confirmed the hypothesis that the GKI values of CP patients strongly correlated with the GDI values. This is due to the fact that these indicators are based on the same parameters--i.e., the time courses of the kinematics of the movement of lower limbs and the pelvis. It also confirmed the hypothesis that the GKI values of CP patients are strongly correlated with the GGI values. The analysis of the results showed that the GKI values differed significantly according to the type of CP and the treatment method. The analysis of the obtained data showed that the values of the GKI in all children in the reference group (without dysfunction of the motor system) do not considerably diverge from one another (Table 3). The largest scatter of the values can be observed in the case of the GGI (Figure 2a), whereas the smallest can be observed in the case of the GDI (Figure 2b). The difference in the orders of magnitude of values between the indices results from the fact that they are built from different parameters and algorithms [22; 23; 24]. Figure 5: Distribution of results of (**a**) GKI, (**b**) GGI and (**c**) GDI in children treated with the different methods. Figure 6: Distribution of results of (**a**) GKI, (**b**) GGI and (**c**) GDI in children with different CP types. Taking into consideration the division of children in terms of methods of treatment, the results obtained in the three sub-groups (rehabilitation, botulinum, rhizotomy) significantly differ from one another in each indicator (\(p<0.05\); Figure 5). Statistically significant differences in all gait indices were also observed in the case of the division of patients in terms of CP types (\(p<0.05\)). The analysis of the distribution of results obtained in the groups of patients divided into CP types revealed statistically significant differences between diplegia and hemiplegia as well as between hemiplegia and quadriplegia; however, it showed the lack of differences between diplegia and quadriplegia (Figure 6). Also, the authors of other works have indicated the presence of statistically significant differences in the case of the GGI and GDI in the group of patients with different types of CP [17; 24; 27]. The values of the GKI in patients with different forms of CP are distributed in a similar way to the values of the GDI and GGL. This fact suggests that the GKI may carry similar clinical information about gait to the indices that have been already applied to the clinical assessment. On the basis of the Pearson correlation results obtained in the reference group, it can be stated that between the GKI and GGI there is a weak dependence, whereas between the GKI and GDI there is a strong linear correlation. This fact makes it possible to conclude that the GKI carries proper clinical information and may be useful in the assessment of gait in patients with CP. Researchers dealing with gait analysis in patients with CP point to the possibility of using gait indices in the assessment of treatment and rehabilitation progress [25; 31].