Immediate Effects Of 20-minute Backward Walking Exercise On Gait And Cerebral Hemodynamics In Young People

Purpose:backward walking is a commonly used gait rehabilitation training in clinical rehabilitation,which is used to improve walking function and balance control ability.Previous studies have shown that the reasons for the rehabilitation effect of inverted walking are the increase of muscle strength of lower limbs and the change of muscle control mode,which are all due to the changes of skeletal muscle system,but few people have explored the changes of central system,especially the cerebral cortex,so this study uses functional near infrared spectroscopy to explore the changes of cerebral cortex after 20 min walking exercise,through the change of the activation degree of cerebral cortex.To investigate the immediate effects of 20 min backward walking exercises on different brain regions,and to explore the appropriate time for single backward walking exercises combined with the space-time parameters of gait,so as to provide a theoretical basis for the application of walking backwards in rehabilitation training.Methods:In the laboratory,PKMAS(150Hz)and near Infrared functional Imaging(3.91Hz)were used to collect the gait spatio-temporal parameters of normal walking and backward walking and the oxygenated hemoglobin concentration parameters of various brain regions before and after 20 min reversing exercise,as well as the gait spatiotemporal parameters of retrograde walking during 20 min inverted walking training.The calculation of gait spatio-temporal parameters and the division of gait cycle are completed by PKMAS own software,and then the oxygen and hemoglobin concentrations in different brain regions during exercise are analyzed by Homer2 based on MATLAB2013 b.According to the selection of the first 25% of all data as regions of interest,five regions of interest are divided into primary sensorimotor cortex,dorsolateral prefrontal lobe,Broca area,orbitofrontal area and primary motor cortex.they are primary sensorimotor cortex,dorsolateral prefrontal lobe,Broca area,orbitofrontal area and primary motor cortex.Two-factor repeated measurement analysis of variance was used to define the(two way repeated ANOVA),significant level as p < 0.05 in the statistical method.Result:The main results are as follows:(1)During the backward walking practice of 20 min,there is a time effect on the impulse(P=0.005),step length(P=0.001),stride width(P=0.001),gait speed,(P=0.001)cadence(P=0.025)and variability of gait cycle(P=0.001)in 20 min.and the spatio-temporal parameters did not change after 15 min.(2)After 20 min walking exercise,the gait cycle in normal gait decreased significantly(P=0.021),while the cadence and gait cycle variability increased significantly(P= 0.02).(3)After 20 min inverted walking exercise,the primary motor cortex increased significantly in inverted walking movement(P= 0.014),and the activation of primary sensorimotor cortex(P=0.007),primary motor cortex(P=0.036),dorsolateral prefrontal area(P=0.028),orbitofrontal region(P=0.033)and Broca area(P=0.046)increased significantly,and the activation degree of Broca area in female was significantly higher than that in male.(4)after 20 min inverted walking exercise,the activation degree of primary sensorimotor cortex,primary motor cortex,dorsolateral prefrontal area,orbitofrontal region and Broca area increased significantly.(4)Backward walking exercises have different effects on men and women.As for the spatio-temporal parameters of gait,the percentage of single supporting phase of male inverted walking increased with time,while that of female decreased with time,and the impulse reduction of positive walking of female was significantly higher than that of male.For the degree of brain activation,after the backward walking exercise,the increase of the activation of the primary sensorimotor cortex of the female was significantly higher than that of the male,and the activation of the Broca area of the female was significantly higher than that of the male in the forward walking.(5)After 20 min walking,in normal gait,males only activated Broca area,while females only activated Broca area at the beginning to activate primary motor cortex,dorsolateral prefrontal lobe,Broca area and orbitofrontal area at the same time.In the backward walking gait,the activation of the dorsolateral prefrontal lobe and orbitofrontal region changed to the activation of the orbitofrontal region and primary motor cortex in males,while the dorsolateral prefrontal erea,orbitofrontal region,Broca area and primary motor cortex were activated in females before and after exercise.however,the ratio of T value of primary motor cortex to T value of prefrontal cortex decreased from 0.66 to 0.59.Conclusions: The main results are as follows:(1)the backward walking exercise can improve the activation degree of the cerebral cortex and change the original activation mode of the cerebral cortex.(2)in the adaptive change of gait during backward walking practice,men prefer motion control strategy,while women prefer gait compensation strategy;for brain activation mode,men are more likely to activate direct motor networks.while women are more likely to activate indirect motor networks.(3)after continuous 15 min,the variability of spatio-temporal parameters of backward walking gait begins to converge,which provides a certain reference for the optimization of practice time of backward walking training.