Background: The most common approach to studying dynamic balance during walking is by applying perturbations. Previous studies that investigated dynamic balance responses predominantly focused on applying perturbations in frontal plane while walking on treadmill. The goal of our work was to develop balance assessment robot (BAR) that can be used during overground walking and to assess normative balance responses to perturbations in transversal plane in a group of neurologically healthy individuals. Methods: BAR provides three passive degrees of freedom (DoF) and three actuated DoF in pelvis that are admittance-controlled in such a way that the natural movement of pelvis is not significantly affected. In this study BAR was used to assess normative balance responses in neurologically healthy individuals by applying linear perturbations in frontal and sagittal planes and angular perturbations in transversal plane of pelvis. One way repeated measure ANOVA was used to statistically evaluate the effect of selected perturbations on stepping responses. Results: Standard deviations of assessed responses were similar in unperturbed and perturbed walking. Perturbations in frontal direction evoked substantial pelvis displacement and caused statistically significant effect on step length, step width and step time. Likewise, perturbations in sagittal plane also caused statistically significant effect on step length, step width and step time but with less explicit impact on pelvis movement in frontal plane. On the other hand, except from substantial pelvis rotation angular perturbations did not have substantial effect on pelvis movement in frontal and sagittal planes while statistically significant effect was noted only in step length and step width after perturbation in clockwise direction. Conclusions: Results indicate that the proposed device can repeatedly reproduce similar experimental conditions. Results also suggest that %stepping strategy% is the dominant strategy for coping with perturbations in frontal plane, perturbations in sagittal plane are to greater extent handled by "ankle strategy" while angular perturbations in transversal plane do not pose substantial challenge for balance. Results also show that specific perturbation in general elicits responses that extend also to other planes of movement that are not directly associated with plane of perturbation as well as to spatio temporal parameters of gait.
COBISS.SI-ID: 2188905
Regaining of the patient's ability to walk after stroke is an important goal of rehabilitation programmes. The ultimate goal of gait rehabilitation is to empower patients for overground walking. We have previously developed a prototype of a therapist-controlled mobile platform with compliant pelvis support mechanism that enables balance training during overground walking (device E-go). The aim of this pilot randomized controlled study was to explore the usefulness of the E-go in reducing the number of therapists needed during walking training, and to explore the effectiveness of the E-go on walking abilities in severely affected stroke patients. The study included 19 subacute poststroke patients divided into two groups. The experimental group (nine patients) trained to walk with the E-go and the control group trained within conventional physiotherapy programs for 3 weeks. Outcome measures were walking distance and speed, Fugl-Meyer Assessment, Berg Balance Scale, Functional Ambulation Category and the number of therapists needed during training. At the end of the training both groups significantly improved in walking speed, walking distance, Berg Balance Scale and Fugl-Meyer Assessment (P%0.001), but there were no between-group differences. The experimental group on average needed a lower number of therapists (P=0.040). These findings highlight the potential of the E-go for overground walking training in severely disabled subacute stroke patients.
COBISS.SI-ID: 2255465
This paper presents the design and implementation of a unique control system for a smart hoist, a therapeutic device that is used in rehabilitation of walking. The control system features a unique human-machine interface that allows the human to intuitively control the system just by moving or rotating its body. The paper contains an overview of the complete system, including the design and implementation of custom sensors, DC servo motor controllers, communication interfaces and embedded-system based central control system. The prototype of the complete system was tested by conducting a 6-runs experiment on 11 subjects and results are showing that the proposed control system interface is indeed intuitive and simple to adopt by the user.
COBISS.SI-ID: 11361364