VR-enhanced walking in people post-stroke: Effect of optic flow speed on the gait biomechanics

2021 ◽  
Vol 90 ◽  
pp. 39
Author(s):  
E. De Keersmaecker ◽  
A. Van Bladel ◽  
N. Lefeber ◽  
B. Jansen ◽  
C. Rodriguez-Guerrero ◽  
...  
Author(s):  
Heidi Nedergård ◽  
Ashokan Arumugam ◽  
Marlene Sandlund ◽  
Anna Bråndal ◽  
Charlotte K. Häger

Abstract Background Robotic-Assisted Gait Training (RAGT) may enable high-intensive and task-specific gait training post-stroke. The effect of RAGT on gait movement patterns has however not been comprehensively reviewed. The purpose of this review was to summarize the evidence for potentially superior effects of RAGT on biomechanical measures of gait post-stroke when compared with non-robotic gait training alone. Methods Nine databases were searched using database-specific search terms from their inception until January 2021. We included randomized controlled trials investigating the effects of RAGT (e.g., using exoskeletons or end-effectors) on spatiotemporal, kinematic and kinetic parameters among adults suffering from any stage of stroke. Screening, data extraction and judgement of risk of bias (using the Cochrane Risk of bias 2 tool) were performed by 2–3 independent reviewers. The Grading of Recommendations Assessment Development and Evaluation (GRADE) criteria were used to evaluate the certainty of evidence for the biomechanical gait measures of interest. Results Thirteen studies including a total of 412 individuals (mean age: 52–69 years; 264 males) met eligibility criteria and were included. RAGT was employed either as monotherapy or in combination with other therapies in a subacute or chronic phase post-stroke. The included studies showed a high risk of bias (n = 6), some concerns (n = 6) or a low risk of bias (n = 1). Meta-analyses using a random-effects model for gait speed, cadence, step length (non-affected side) and spatial asymmetry revealed no significant differences between the RAGT and comparator groups, while stride length (mean difference [MD] 2.86 cm), step length (affected side; MD 2.67 cm) and temporal asymmetry calculated in ratio-values (MD 0.09) improved slightly more in the RAGT groups. There were serious weaknesses with almost all GRADE domains (risk of bias, consistency, directness, or precision of the findings) for the included outcome measures (spatiotemporal and kinematic gait parameters). Kinetic parameters were not reported at all. Conclusion There were few relevant studies and the review synthesis revealed a very low certainty in current evidence for employing RAGT to improve gait biomechanics post-stroke. Further high-quality, robust clinical trials on RAGT that complement clinical data with biomechanical data are thus warranted to disentangle the potential effects of such interventions on gait biomechanics post-stroke.


2019 ◽  
Author(s):  
Callum Mole ◽  
Gustav Markkula ◽  
Oscar Giles ◽  
Yuki Okafuji ◽  
Richard Romano ◽  
...  

2016 ◽  
Vol 3 (5) ◽  
pp. 160096 ◽  
Author(s):  
Georgios K. Kountouriotis ◽  
Callum D. Mole ◽  
Natasha Merat ◽  
Richard M. Wilkie

How do animals follow demarcated paths? Different species are sensitive to optic flow and one control solution is to maintain the balance of flow symmetry across visual fields; however, it is unclear whether animals are sensitive to changes in asymmetries when steering along curved paths. Flow asymmetries can alter the global properties of flow (i.e. flow speed) which may also influence steering control. We tested humans steering curved paths in a virtual environment. The scene was manipulated so that the ground plane to either side of the demarcated path produced larger or smaller asymmetries in optic flow. Independent of asymmetries and the locomotor speed, the scene properties were altered to produce either faster or slower globally averaged flow speeds. Results showed that rather than being influenced by changes in flow asymmetry, steering responded to global flow speed. We conclude that the human brain performs global averaging of flow speed from across the scene and uses this signal as an input for steering control. This finding is surprising since the demarcated path provided sufficient information to steer, whereas global flow speed (by itself) did not. To explain these findings, existing models of steering must be modified to include a new perceptual variable: namely global optic flow speed.


Author(s):  
Emma De Keersmaecker ◽  
Nina Lefeber ◽  
Ben Serrien ◽  
Bart Jansen ◽  
Carlos Rodriguez-Guerrero ◽  
...  

2009 ◽  
Vol 64B (2) ◽  
pp. 222-231 ◽  
Author(s):  
Y.-h. Chou ◽  
R. C. Wagenaar ◽  
E. Saltzman ◽  
J. E. Giphart ◽  
D. Young ◽  
...  

2010 ◽  
Vol 31 (4) ◽  
pp. 433-437 ◽  
Author(s):  
Anat Mirelman ◽  
Benjamin L. Patritti ◽  
Paolo Bonato ◽  
Judith E. Deutsch

Perception ◽  
10.1068/p5845 ◽  
2007 ◽  
Vol 36 (10) ◽  
pp. 1465-1475 ◽  
Author(s):  
Frank H Durgin ◽  
Krista Gigone

We tested the hypothesis that long-term adaptation to the normal contingencies between walking and its multisensory consequences (including optic flow) leads to enhanced discrimination of appropriate visual speeds during self-motion. In experiments 1 (task 1) and 2 a two-interval forced-choice procedure was used to compare the perceived speed of a simulated visual flow field viewed while walking with the perceived speed of a flow field viewed while standing. Both experiments demonstrated subtractive reductions in apparent speed. In experiments 1 and 3 discrimination thresholds were measured for optic flow speed while walking and while standing. Consistent with the optimal-coding hypothesis, speed discrimination for visual speeds near walking speed was enhanced during walking. Reduced sensitivity was found for slower visual speeds. The multisensory context of walking alters the coding of optic flow in a way that enhances speed discrimination in the expected range of flow speeds.


Sign in / Sign up

Export Citation Format

Share Document