# modified two point gait

The small discrepancy shows that the generated joint angle has high similarity with the joint of human walking. The affected leg is advanced between the crutches to the stairs in a modified two-point gait. The currently available exoskeleton for assisting the paraplegic patient in walking usually adapts a pre-programmed gait that involves the patient following an exoskeleton lead. This study introduces a new classification for this coordination pattern that expands on a current data analysis technique by introducing the terms in-phase with proximal dominancy, in-phase with distal dominancy, anti-phase with proximal dominancy and anti-phase with distal dominancy. After prediction at the beginning of each step, half of the walking cycle was used as the time consumed to generate the walking motion using ZMP. The use of NIP makes up for this shortcoming, thereby enables the modified trajectory to conform to human walking habits. The authors declare that they have no competing interests. (7), we can obtain the below equation: By substituting the solution (10) into the Eqs. Huang in proposed a stable gait generator based on a newly proposed gait pattern in using the interpolation function. The proposed gait generation and modification method were validated by simulation using the Gazebo software. J Neurophysiol 97(2):1809–1818, Dietz V, Fouad K, Bastiaanse C (2001) Neuronal coordination of arm and leg movements during human locomotion. IEEE Transact Neural Syst Rehabil Eng 20(3):247–257, Crocher V, Jarrassé N, Sahbani A, Roby-Brami A, Morel G (2011) Changing human upper-limb synergies with an exoskeleton using viscous fields. To generate a human-like gait, a non-linear inverted pendulum (NIP) model was used to modify the walking trajectory generated by walking synergy. In our study, the target patient is paraplegic. the aid is held in UE opposite to LE that requires protection. Another two-point gait pattern is the modified two-point pattern. Therefore, to make the walking synergy-based gait fits with the patient wearing the powered exoskeleton, we modified the walking gait by employing ZMP. For the NIP, the length of the pendulum remains constant and the generated walking motion has a fully stretched knee joint on stance leg, which is similar to the human walking habit. studied the synergy between arms and legs by measuring the electromyographic on leg and arms during walking [15]. 34(5):630–637, Kajita S, Kanehiro F, Kaneko K, Fujiwara K, Harada K, Yokoi K Hirukawa: Biped walking pattern generation by using preview control of zero-moment point, Park JH, Kim KD (1998) Biped robot walking using gravity-compensated inverted pendulum mode and computed torque control. Terms and Conditions, Comparison between robot walking with and without gait modification. Sankai et al. statement and The NIP model can be used to generate a stable CoM trajectory, in which the resultant ZMP stays in the support polygon formed by the cane and foot. where $$\Gamma$$ is the matrix of the eigenvectors in descending order concerning the eigenvalues. Three subjects participated in this experiment and comprise of all-male, healthy, aged from 25 to 30 and without any history of movement disorder. A swing-through gait 4. Comparison of human gait, gait generated suing synergy and modified gait. The walking gait generated from the walking synergy might not result in a fully stable walk due to the dynamic difference between the lower-limb exoskeleton and a human subject. A modified two-point gait. Firstly, the walking trajectory generated using ZMP becomes stable. (widening the BOS & shifting COG away from protected LE) aid and pt. In the case of the knee joint angle, the mean error and maximum errors are 2.54 [deg] and 15.96 [deg], respectively. The walking synergy was extracted from a healthy subject and applied to synchronize the exoskeleton’s movement with the user’s intention. During the stance phase of the human walking the stance leg becomes fully extended, which makes the LIP model not in accordance with the natural human walking. The pre-programmed trajectory method is not the only solution to generate the exoskeleton movement. This pattern does require the patient to coordinate moving an assistive gait device and the contralateral lower extremity at the same time. (10) can be obtained as follow: Using Eq. "Motion planning using NIP and ZMP" section introduces ZMP and NIP for motion planning. Copyright © 2021 Elsevier B.V. or its licensors or contributors. In the present study we use a nonlinear inverted pendulum (NIP) to generate the CoM trajectory, subsequently, the leg joint angle can be obtained by solving the inverse kinematics. \end{aligned}$$,$$\begin{aligned} x=\Gamma y. The detail explanation of using principal component analysis (PCA) to analyze human walking synergy is described in [25, 26]. This pattern is less stable than the four-point pattern. © 2021 BioMed Central Ltd unless otherwise stated. The details can be described below. LE and aid advance alternately (four-point) or simultaneously (two-point) ; aid is typically used on the contralateral side. (1987), Hamill et al. The major contribution in this paper is the gait modification method based on ZMP to improve the walking stability of a paraplegic patient wearing an exoskeleton. Furthermore, a nonlinear inverted pendulum (NIP) model was utilized in order to generate a gait with a fully stretched knee joint angle that is similar to human gait. The error increases with an increase in the Gazebo software the modification of generated! Should be improved to better conform to human walking habits leg during and! 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