Introduction. The article presents the results of the analysis of the effect of the difference in the length of the lower extremities on the biomechanical walking parameter. Diagnosis of posture of a person would not be complete without measuring and assessing the condition of the support-spring characteristics of the foot. The modern stage of the development of instrument making actualizes the applied aspect of the analysis of human locomotives. The purpose of this work is to develop a method for analyzing the effect of different lengths of the lower extremities on the biomechanical parameters of the gait, increasing the accuracy of the study of the deformations of the feet and their quantitative evaluation. Method and results of research. The ways of solving this problem are considered, namely, the complex approach with the use of analysis and generalization of the data of the specialized scientific-methodical literature is applied; visual screening; baropodometry; planography and methods of mathematical statistics. As a research object, two groups of people were selected: control (healthy) and experimental (with a shortening of one of the lower extremities). In the course of the study, the effect of the multiplicity of the lower extremities on the biomechanical parameters of motion for the control and experimental groups of the subjects was analyzed. It was established that the subjects with a shortened length of one of the lower limbs, with a dynamic examination, with an increase in the difference in length, increases the total load on the foot of the shortened limb, the force of the forward push and the load on the front of the foot. An increase in the duration of support for the intact limb created a picture of asymmetry or lameness, the relative weakness of the leg muscles of the affected limb caused the subjects with caution to carry out the anterior and posterior shocks, which were lowered compared with the norm. Conclusions. The results of this study can be successfully used for further research in the field of clinical analysis of motor activity, foot stance monitoring and become a tool for assessing the effectiveness of various methods of treating the musculoskeletal system. In addition, the results can be used in research and serve as an expert assessment of functional disorders in patients with damage to the musculoskeletal and nervous systems, and vestibular disorders system.