# Application of the Gait Kinematics Index in Patients with Cerebral Palsy
## 4 Discussion
What seems essential, however, is the verification of which of the indices constitutes the most sensitive measure for the evaluation of differences before and after the treatment of patients with CP. [PERSON] et al. [25] made an attempt to compare the GGI, GDI and GPS/GDI* (designation of the transformed GPS as the GDI*) values in the population of individuals with typical pathologies of gait (seven groups of patients with various types of gait pathologies who were subjected to surgical procedures) in order to assess the sensitivity of the indices and their clinical significance. The aforementioned authors found that the most sensitive indices in terms of the evaluation of differences before and after treatment are the GDIi and then the GPS/GDI*, whereas the GGI has nonparametric properties and its results are difficult to interpret intuitively [25; 31]. The results of this study have shown that the new GKI is sensitive to the differences in the values in terms of the types of CP and the level of dysfunctions (qualification for different methods of treatment). The successive stage of this research should verify the possibilities of applying the GKI to the assessment of treatment/rehabilitation progress. It should also verify the index sensitivity in the evaluation of differences before and after treatment. In spite of the great contribution that all the gait indices represent for clinical assessment, one should be critical of them and remember the limitations of these methods. The already known gait indices are characterized by complicated mathematical algorithms. Nearly all the indices enable the evaluation of gait using one non-dimensional numerical values. [23; 24; 27]. Nevertheless, gait indicators are used in clinical practice [32; 33]. Doubts concerning the clinical application of gait indexes can be found in scientific publications by other authors [25; 34]. According to [PERSON] et al., the assessment of locomotor functions based on a single numerical value lacks information about movement in individual joints and successive moments [26]. Taking into consideration the doubts raised with respect to the evaluation of gait based on a single numerical value and the fact that it does not provide a complex diagnostic method, it seems that the new comprehensive method of gait pathology evaluation--the Gait Kinematics Index, Global Symmetry Index and Gait Deviations Profile--can find applications in clinical establishments and movement analysis laboratories. However, it should not be forgotten that the limitation in indicator methods is the arbitrary selection of parameters, which takes into consideration only kinematic values and omits kinetic and electromyographic data. Gait indices are sensitive to the results obtained in the control group. Such results are specific to each laboratory, which may affect the differences in the mean values and result in an oversight of significant gait changesin patients [17; 23; 24; 34]. The aforementioned limitation should be taken into account in any research using index methods. In the near future, not only will new index methods be applied to the clinical assessment of gait, but methods based on Artificial Intelligence (AI) will also be applied. The authors fully realize the limitations of this study. Undoubtedly, a different number of individuals in particular groups constitutes a limitation. This was caused by the specific nature of CP and the fact that the researchers tested all patients who were under the care of the USCHC at the time of the study, without without having influence on the type of a patient. As a result, the particular groups divided based on forms of CP and methods of treatment did not have a uniform number of patients.