Gait planning and double support phase model for functional electrical stimulation-based walking

2012 ◽  
Author(s):  
Nitin Sharma ◽  
R. Stein
Keyword(s):  
Electrical Stimulation ◽  
Functional Electrical Stimulation ◽  
Phase Model ◽  
Gait Planning ◽  
Double Support ◽  
Support Phase ◽  
Double Support Phase

scholarly journals A Low-Cost Biofeedback System for Electromyogram-Triggered Functional Electrical Stimulation Therapy: An Indo-German Feasibility Study

ISRN Stroke ◽  
2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
Alakananda Banerjee ◽  
Bhawna Khattar ◽  
Anirban Dutta
Keyword(s):  
Electrical Stimulation ◽  
Functional Electrical Stimulation ◽  
Low Cost ◽  
Surface Emg ◽  
Treadmill Walking ◽  
Medial Gastrocnemius ◽  
Double Support ◽  
Biofeedback System ◽  
Normative Value ◽  
Support Phase

Functional electrical stimulation (FES) facilitates ambulatory function after paralysis by activating the muscles of the lower extremities. The FES-assisted stepping can either be triggered by a heel-swich, or by an electromyogram-(EMG-) based gait event detector. A group of six chronic (>6 months poststroke) hemiplegic stroke survivors underwent transcutaneous FES-assisted training for 1 hour on stepping task with EMG biofeedback from paretic tibialis anterior (TA) and medial gastrocnemius (GM) muscles, where the stimulation of the paretic TA or GM was triggered with surface EMG from the same muscle. During the baseline, postintervention, and 2-day-postintervention assessments, a total of 5 minutes of surface EMG was recorded from paretic GM and TA muscles during volitional treadmill walking. Two-way ANOVA showed significant effects in terms of P values for the 6 stroke subjects, 0.002, the 3 assessments, 0, and the interaction between subjects and assessments, 6.21E-19. The study showed a significant improvement from baseline in paretic GM and TA muscles coordination during volitional treadmill walking. Moreover, it was found that the EMG-triggered FES-assisted therapy for stand-to-walk transition helped in convergence of the deviation in centroidal angular momentum from the normative value to a quasi-steady state during the double-support phase of the nonparetic. Also, the observational gait analysis showed improvement in ankle plantarflexion during late stance, knee flexion, and ground clearance of the foot during swing phase of the gait.

scholarly journals Overground Walking Decreases Alpha Activity and Entrains Eye Movements in Humans

2020 ◽  
Vol 14 ◽  
Author(s):  
Liyu Cao ◽  
Xinyu Chen ◽  
Barbara F. Haendel
Keyword(s):  
Eye Movements ◽  
Neuronal Activity ◽  
Walking Speed ◽  
Alpha Activity ◽  
Alpha Power ◽  
Electrode Impedance ◽  
Blink Rate ◽  
Double Support ◽  
Support Phase ◽  
Double Support Phase

Experiments in animal models have shown that running increases neuronal activity in early visual areas in light as well as in darkness. This suggests that visual processing is influenced by locomotion independent of visual input. Combining mobile electroencephalography, motion- and eye-tracking, we investigated the influence of overground free walking on cortical alpha activity (~10 Hz) and eye movements in healthy humans. Alpha activity has been considered a valuable marker of inhibition of sensory processing and shown to negatively correlate with neuronal firing rates. We found that walking led to a decrease in alpha activity over occipital cortex compared to standing. This decrease was present during walking in darkness as well as during light. Importantly, eye movements could not explain the change in alpha activity. Nevertheless, we found that walking and eye related movements were linked. While the blink rate increased with increasing walking speed independent of light or darkness, saccade rate was only significantly linked to walking speed in the light. Pupil size, on the other hand, was larger during darkness than during light, but only showed a modulation by walking in darkness. Analyzing the effect of walking with respect to the stride cycle, we further found that blinks and saccades preferentially occurred during the double support phase of walking. Alpha power, as shown previously, was lower during the swing phase than during the double support phase. We however could exclude the possibility that the alpha modulation was introduced by a walking movement induced change in electrode impedance. Overall, our work indicates that the human visual system is influenced by the current locomotion state of the body. This influence affects eye movement pattern as well as neuronal activity in sensory areas and might form part of an implicit strategy to optimally extract sensory information during locomotion.

Development of multi-phase dynamic equations for a seven-link biped robot with improved foot rotation in the double support phase

2014 ◽  
Vol 229 (1) ◽  
pp. 3-17 ◽  
Author(s):  
Farsam Farzadpour ◽  
Mohammad Danesh ◽  
Seyed M TorkLarki
Keyword(s):  
Power Consumption ◽  
Trajectory Generation ◽  
Biped Robot ◽  
Dynamic Equations ◽  
Total Power ◽  
Phase Dynamic ◽  
Double Support ◽  
Multi Phase ◽  
Support Phase ◽  
Double Support Phase

Gait generation plays a significant role in the quality of locomotion of legged robots. This paper presents the development of multi-phase dynamic equations and optimal trajectory generation for a seven-link planar-biped robot walking on the ground level with consideration of feet rotation in the double support phase. The main contribution of this paper is to increase the stability margin at the phase transition time for simultaneous feet rotation in double support phase by introducing a new style of feet rotation. First, the derivation of the dynamics equations, which is a challenging problem due to the existence of the holonomic constraints, is performed using the Lagrangian formulation. Then, an analytical solution to inverse kinematics is proposed to determine the angles of each joint. A multi-objective genetic algorithm-based optimization technique is proposed to obtain the key parameters in trajectory generation so that the zero moment point tracks a predefined stable trajectory and additionally minimizes the power consumption, which is subjected to actuators’ powers limitations. The effect of the hip height on the total power consumption is also investigated. The numerical simulations demonstrate the effectiveness of the proposed method.

scholarly journals Dynamics of corticospinal motor control during overground and treadmill walking in humans

2017 ◽  
Author(s):  
Luisa Roeder ◽  
Tjeerd W Boonstra ◽  
Simon S Smith ◽  
Graham K Kerr
Keyword(s):  
Treadmill Walking ◽  
Human Gait ◽  
Time Lags ◽  
Evoked Responses ◽  
Double Support ◽  
Time Frequency ◽  
Gamma Frequencies ◽  
Alpha Beta ◽  
Support Phase ◽  
Double Support Phase

AbstractIncreasing evidence suggests cortical involvement in the control of human gait. However, the nature of corticospinal interactions remains poorly understood. We performed time-frequency analysis of electrophysiological activity acquired during treadmill and overground walking in 22 healthy, young adults. Participants walked at their preferred speed (4.2, SD 0.4 km h−1), which was matched across both gait conditions. Event-related power, corticomuscular coherence (CMC) and inter-trial coherence (ITC) were assessed for EEG from bilateral sensorimotor cortices and EMG from the bilateral tibialis anterior (TA) muscles. Cortical power, CMC and ITC at theta, alpha, beta and gamma frequencies (4-45 Hz) increased during the double support phase of the gait cycle for both overground and treadmill walking. High beta (21-30 Hz) CMC and ITC of EMG was significantly increased during overground compared to treadmill walking, as well as EEG power in theta band (4-7 Hz). The phase spectra revealed positive time lags at alpha, beta and gamma frequencies, indicating that the EEG response preceded the EMG response. The parallel increases in power, CMC and ITC during double support suggest evoked responses at spinal and cortical populations rather than a modulation of ongoing corticospinal oscillatory interactions. The evoked responses are not consistent with the idea of synchronization of ongoing corticospinal oscillations, but instead suggest coordinated cortical and spinal inputs during the double support phase. Frequency-band dependent differences in power, CMC and ITC between overground and treadmill walking suggest differing neural control for the two gait modalities, emphasizing the task-dependent nature of neural processes during human walking.New & NoteworthyWe investigated cortical and spinal activity during overground and treadmill walking in healthy adults. Parallel increases in power, CMC and ITC during double support suggest evoked responses at spinal and cortical populations rather than a modulation of ongoing corticospinal oscillatory interactions. These findings identify neurophysiological mechanisms that are important for understanding cortical control of human gait in health and disease.

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