scholarly journals Dynamic Balance Gait for Walking Assistance Exoskeleton

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Qiming Chen ◽  
Hong Cheng ◽  
Chunfeng Yue ◽  
Rui Huang ◽  
Hongliang Guo

Purpose. Powered lower-limb exoskeleton has gained considerable interests, since it can help patients with spinal cord injury(SCI) to stand and walk again. Providing walking assistance with SCI patients, most exoskeletons are designed to follow predefined gait trajectories, which makes the patient walk unnaturally and feels uncomfortable. Furthermore, exoskeletons with predefined gait trajectories cannot always maintain balance walking especially when encountering disturbances. Design/Methodology/Approach. This paper proposed a novel gait planning approach, which aims to provide reliable and balance gait during walking assistance. In this approach, we model the exoskeleton and patient together as a linear inverted pendulum (LIP) and obtain the patients intention through orbital energy diagram. To achieve dynamic gait planning of exoskeleton, the dynamic movement primitive (DMP) is utilized to model the gait trajectory. Meanwhile, the parameters of DMP are updated dynamically during one step, which aims to improve the ability of counteracting external disturbance. Findings. The proposed approach is validated in a human-exoskeleton simulation platform, and the experimental results show the effectiveness and advantages of the proposed approach. Originality/Value. We decomposed the issue of obtain dynamic balance gait into three parts: (1) based on the sensory information of exoskeleton, the intention estimator is designed to estimate the intention of taking a step; (2) at the beginning of each step, the discrete gait planner utilized the obtained gait parameters such as step length S and step duration T and generate the trajectory of swing foot based on S,T; (3) during walking process, continuous gait regulator is utilized to adjust the gait generated by discrete gait planner to counteract disturbance.

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1343
Author(s):  
Sebastian Fudickar ◽  
Jörn Kiselev ◽  
Christian Stolle ◽  
Thomas Frenken ◽  
Elisabeth Steinhagen-Thiessen ◽  
...  

This article covers the suitability to measure gait-parameters via a Laser Range Scanner (LRS) that was placed below a chair during the walking phase of the Timed Up&Go Test in a cohort of 92 older adults (mean age 73.5). The results of our study demonstrated a high concordance of gait measurements using a LRS in comparison to the reference GAITRite walkway. Most of aTUG’s gait parameters demonstrate a strong correlation coefficient with the GAITRite, indicating high measurement accuracy for the spatial gait parameters. Measurements of velocity had a correlation coefficient of 99%, which can be interpreted as an excellent measurement accuracy. Cadence showed a slightly lower correlation coefficient of 96%, which is still an exceptionally good result, while step length demonstrated a correlation coefficient of 98% per leg and stride length with an accuracy of 99% per leg. In addition to confirming the technical validation of the aTUG regarding its ability to measure gait parameters, we compared results from the GAITRite and the aTUG for several parameters (cadence, velocity, and step length) with results from the Berg Balance Scale (BBS) and the Activities-Specific Balance Confidence-(ABC)-Scale assessments. With confidence coefficients for BBS and velocity, cadence and step length ranging from 0.595 to 0.798 and for ABC ranging from 0.395 to 0.541, both scales demonstrated only a medium-sized correlation. Thus, we found an association of better walking ability (represented by the measured gait parameters) with better balance (BBC) and balance confidence (ABC) overall scores via linear regression. This results from the fact that the BBS incorporates both static and dynamic balance measures and thus, only partly reflects functional requirements for walking. For the ABC score, this effect was even more pronounced. As this is to our best knowledge the first evaluation of the association between gait parameters and these balance scores, we will further investigate this phenomenon and aim to integrate further measures into the aTUG to achieve an increased sensitivity for balance ability.


Sensors ◽  
2020 ◽  
Vol 20 (24) ◽  
pp. 7216
Author(s):  
Wei Yang ◽  
Jiyu Zhang ◽  
Sheng Zhang ◽  
Canjun Yang

With the help of wearable robotics, the lower limb exoskeleton becomes a promising solution for spinal cord injury (SCI) patients to recover lower body locomotion ability. However, fewer exoskeleton gait planning methods can meet the needs of patient in real time, e.g., stride length or step width, etc., which may lead to human-machine incoordination, limit comfort, and increase the risk of falling. This work presents a human-exoskeleton-crutch system with the center of pressure (CoP)-based gait planning method to enable the balance control during the exoskeleton-assisted walking with crutches. The CoP generated by crutches and human-machine feet makes it possible to obtain the overall stability conditions of the system in the process of exoskeleton-assisted quasi-static walking, and therefore, to determine the next stride length and ensure the balance of the next step. Thus, the exoskeleton gait is planned with the guidance of stride length. It is worth emphasizing that the nominal reference gait is adopted as a reference to ensure that the trajectory of the swing ankle mimics the reference one well. This gait planning method enables the patient to adaptively interact with the exoskeleton gait. The online gait planning walking tests with five healthy volunteers proved the method’s feasibility. Experimental results indicate that the algorithm can deal with the sensed signals and plan the landing point of the swing leg to ensure balanced and smooth walking. The results suggest that the method is an effective means to improve human–machine interaction. Additionally, it is meaningful for the further training of independent walking stability control in exoskeletons for SCI patients with less assistance of crutches.


2014 ◽  
Vol 39 (4) ◽  
pp. 286-292 ◽  
Author(s):  
Mokhtar Arazpour ◽  
Masoud Gharib ◽  
Stephen William Hutchins ◽  
Monireh Ahmadi Bani ◽  
Sarah Curran ◽  
...  

Background:Spinal cord injury patients walk with a flexed trunk when using reciprocating gait orthoses. Reduction of trunk flexion during ambulation may produce an improvement in gait parameters for reciprocating gait orthosis users.Objectives:To investigate the effect on kinematics and temporal–spatial parameters when spinal cord injury patients ambulate with an advanced reciprocating gait orthosis while wearing a thoracolumbosacral orthosis to provide trunk extension.Study design:Comparative study between before and after use o thoracolumbosacral orthosis with the advanced reciprocating gait orthoses.Methods:Four patients with spinal cord injury were fitted with an advanced reciprocating gait orthosis and also wore a thoracolumbosacral orthosis. Patients walked along a flat walkway either with or without the thoracolumbosacral orthosis at their self-selected walking speed. Temporal–spatial parameters and lower limb kinematics were analyzed.Results:Mean walking speed, step length, and cadence all improved when walking with the thoracolumbosacral orthosis donned compared to the trunk support offered by the advanced reciprocating gait orthosis. Hip and ankle joint ranges of motion were significantly increased when wearing the thoracolumbosacral orthosis during ambulation.Conclusion:Using an advanced reciprocating gait orthosis when wearing a thoracolumbosacral orthosis can improve walking speed and the step length of walking as compared with walking with an advanced reciprocating gait orthosis, probably due to the extended position of the trunk.Clinical relevanceDonning the thoracolumbosacral orthosis produced a relatively extended trunk position in the advanced reciprocating gait orthosis for all the patients included in the study, which resulted in improved gait parameters.


2012 ◽  
Vol 37 (1) ◽  
pp. 70-75 ◽  
Author(s):  
Mokhtar Arazpour ◽  
Hamid Reza Tajik ◽  
Gholamreza Aminian ◽  
Monireh Ahmadi Bani ◽  
Farhad Tabatabai Ghomshe ◽  
...  

Background:Ankle foot orthoses (AFOs) are usually used for patients with incomplete spinal cord injury (ISCI) to provide support in walking.Objectives:The aim of this study was to compare the effect of AFOs, with and without ankle hinges, on specific gait parameters during treadmill training by subjects with ISCI.Study Design:Quasi-experimental.Methods:Five patients with ISCI at the thoracic level participated in this study. Gait evaluation was performed when walking 1) barefoot 2) wearing a solid AFO and 3) wearing a hinged AFO.Results:The mean step length when walking barefoot was 26.3 ± 16.37cm compared to 31.3 ± 17.27 cm with a solid AFO and 28.5 ± 15.86 cm with a hinged AFO. The mean cadence for walking barefoot was 61.59 ± 25.65 steps/min. compared to 50.94 ± 22.36 steps/min. with a solid AFO and 56.25 ± 24.44 steps/min with a hinged AFO. Significant differences in cadence and step length during walking were only demonstrated between the barefoot condition and when wearing a solid AFO. Significant difference was not observed between conditions in mean of ankle range of motion.Conclusion:The solid AFO was the only condition which improved cadence and step length in patients during ISCI gait training.Clinical relevanceA solid AFO could be used permanently to compensate for impaired ankle function or it could be used while retraining stepping.


2020 ◽  
Vol 17 (6) ◽  
pp. 172988142097634
Author(s):  
Huan Tran Thien ◽  
Cao Van Kien ◽  
Ho Pham Huy Anh

This article proposes a new stable biped walking pattern generator with preset step-length value, optimized by multi-objective JAYA algorithm. The biped robot is modeled as a kinetic chain of 11 links connected by 10 joints. The inverse kinematics of the biped is applied to derive the specified biped hip and feet positions. The two objectives related to the biped walking stability and the biped to follow the preset step-length magnitude have been fully investigated and Pareto optimal front of solutions has been acquired. To demonstrate the effectiveness and superiority of proposed multi-objective JAYA, the results are compared to those of MO-PSO and MO-NSGA-2 optimization approaches. The simulation and experiment results investigated over the real small-scaled biped HUBOT-4 assert that the multi-objective JAYA technique ensures an outperforming effective and stable gait planning and walking for biped with accurate preset step-length value.


2021 ◽  
pp. 154596832110193
Author(s):  
Sungwoo Park ◽  
Chang Liu ◽  
Natalia Sánchez ◽  
Julie K. Tilson ◽  
Sara J. Mulroy ◽  
...  

Background People poststroke often walk with a spatiotemporally asymmetric gait, due in part to sensorimotor impairments in the paretic lower extremity. Although reducing asymmetry is a common objective of rehabilitation, the effects of improving symmetry on balance are yet to be determined. Objective We established the concurrent validity of whole-body angular momentum as a measure of balance, and we determined if reducing step length asymmetry would improve balance by decreasing whole-body angular momentum. Methods We performed clinical balance assessments and measured whole-body angular momentum during walking using a full-body marker set in a sample of 36 people with chronic stroke. We then used a biofeedback-based approach to modify step length asymmetry in a subset of 15 of these individuals who had marked asymmetry and we measured the resulting changes in whole-body angular momentum. Results When participants walked without biofeedback, whole-body angular momentum in the sagittal and frontal plane was negatively correlated with scores on the Berg Balance Scale and Functional Gait Assessment supporting the validity of whole-body angular momentum as an objective measure of dynamic balance. We also observed that when participants walked more symmetrically, their whole-body angular momentum in the sagittal plane increased rather than decreased. Conclusions Voluntary reductions of step length asymmetry in people poststroke resulted in reduced measures of dynamic balance. This is consistent with the idea that after stroke, individuals might have an implicit preference not to deviate from their natural asymmetry while walking because it could compromise their balance. Clinical Trials Number: NCT03916562.


Entropy ◽  
2021 ◽  
Vol 23 (7) ◽  
pp. 848
Author(s):  
Karla Miriam Reyes Leiva ◽  
Milagros Jaén-Vargas ◽  
Miguel Ángel Cuba ◽  
Sergio Sánchez Lara ◽  
José Javier Serrano Olmedo

The rehabilitation of a visually impaired person (VIP) is a systematic process where the person is provided with tools that allow them to deal with the impairment to achieve personal autonomy and independence, such as training for the use of the long cane as a tool for orientation and mobility (O&M). This process must be trained personally by specialists, leading to a limitation of human, technological and structural resources in some regions, especially those with economical narrow circumstances. A system to obtain information about the motion of the long cane and the leg using low-cost inertial sensors was developed to provide an overview of quantitative parameters such as sweeping coverage and gait analysis, that are currently visually analyzed during rehabilitation. The system was tested with 10 blindfolded volunteers in laboratory conditions following constant contact, two points touch, and three points touch travel techniques. The results indicate that the quantification system is reliable for measuring grip rotation, safety zone, sweeping amplitude and hand position using orientation angles with an accuracy of around 97.62%. However, a new method or an improvement of hardware must be developed to improve gait parameters’ measurements, since the step length measurement presented a mean accuracy of 94.62%. The system requires further development to be used as an aid in the rehabilitation process of the VIP. Now, it is a simple and low-cost technological aid that has the potential to improve the current practice of O&M.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Antonietta Canna ◽  
Lauri J. Lehto ◽  
Lin Wu ◽  
Sheng Sang ◽  
Hanne Laakso ◽  
...  

AbstractEpidural spinal cord stimulation (ESCS) is widely used for chronic pain treatment, and is also a promising tool for restoring motor function after spinal cord injury. Despite significant positive impact of ESCS, currently available protocols provide limited specificity and efficiency partially due to the limited number of contacts of the leads and to the limited flexibility to vary the spatial distribution of the stimulation field in respect to the spinal cord. Recently, we introduced Orientation Selective (OS) stimulation strategies for deep brain stimulation, and demonstrated their selectivity in rats using functional MRI (fMRI). The method achieves orientation selectivity by controlling the main direction of the electric field gradients using individually driven channels. Here, we introduced a similar OS approach for ESCS, and demonstrated orientation dependent brain activations as detected by brain fMRI. The fMRI activation patterns during spinal cord stimulation demonstrated the complexity of brain networks stimulated by OS-ESCS paradigms, involving brain areas responsible for the transmission of the motor and sensory information. The OS approach may allow targeting ESCS to spinal fibers of different orientations, ultimately making stimulation less dependent on the precision of the electrode implantation.


2021 ◽  
Vol 35 (2) ◽  
pp. 131-144
Author(s):  
Maijke van Bloemendaal ◽  
Sicco A. Bus ◽  
Frans Nollet ◽  
Alexander C. H. Geurts ◽  
Anita Beelen

Background. Many stroke survivors suffer from leg muscle paresis, resulting in asymmetrical gait patterns, negatively affecting balance control and energy cost. Interventions targeting asymmetry early after stroke may enhance recovery of walking. Objective. To determine the feasibility and preliminary efficacy of up to 10 weeks of gait training assisted by multichannel functional electrical stimulation (MFES gait training) applied to the peroneal nerve and knee flexor or extensor muscle on the recovery of gait symmetry and walking capacity in patients starting in the subacute phase after stroke. Methods. Forty inpatient participants (≤31 days after stroke) were randomized to MFES gait training (experimental group) or conventional gait training (control group). Gait training was delivered in 30-minute sessions each workday. Feasibility was determined by adherence (≥75% sessions) and satisfaction with gait training (score ≥7 out of 10). Primary outcome for efficacy was step length symmetry. Secondary outcomes included other spatiotemporal gait parameters and walking capacity (Functional Gait Assessment and 10-Meter Walk Test). Linear mixed models estimated treatment effect postintervention and at 3-month follow-up. Results. Thirty-seven participants completed the study protocol (19 experimental group participants). Feasibility was confirmed by good adherence (90% of the participants) and participant satisfaction (median score 8). Both groups improved on all outcomes over time. No significant group differences in recovery were found for any outcome. Conclusions. MFES gait training is feasible early after stroke, but MFES efficacy for improving step length symmetry, other spatiotemporal gait parameters, or walking capacity could not be demonstrated. Trial Registration. Netherlands Trial Register (NTR4762).


Author(s):  
Seobin Choi ◽  
Jieon Lee ◽  
Gwanseob Shin

Stiff-knee, which indicates reduced range of knee flexion, may decrease gait stability. Although it is closely related to an increase in fall risk, the effect of limited knee flexion on the balance capacity during walking has not been well studied. This study aimed at examining how walking with limited knee flexion would influence the center of pressure (COP) trajectory and spatiotemporal gait parameters. Sixteen healthy young participants conducted four different walking conditions: normal walking and walking with limited knee flexion of their left knee up to 40 and 20 degrees, respectively. Results show that the participants walked significantly (p<0.05) slower with shorter stride length, wider step width, less cadence, and decreased stance phase when walking with limited knee flexion, compared to normal walking. The increase in the asymmetry and variability of the COP was also observed. It indicates that limited knee flexion during walking might affect the dynamic balance.


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