scholarly journals The Effect of a Virtual No-Step Zone on Balance Control in Walking

2020 ◽  
Author(s):  
Tyler Fettrow ◽  
Stephen DiBianca ◽  
Fernando Vanderlinde dos Santos ◽  
Hendrik Reimann ◽  
John Jeka
Keyword(s):  
Neural Control ◽  
Gait Cycle ◽  
Balance Control ◽  
Vestibular Stimulation ◽  
Environmental Constraints ◽  
Sporting Events ◽  
Complex Environments ◽  
Foot Placement ◽  
Ankle Inversion ◽  
The Right

AbstractHumans need to actively control their upright posture during walking to avoid loss of balance. We do not have a comprehensive theory for how humans regulate balance during walking, especially in complex environments. Balance must be maintained in a variety of contexts including crowded city side-walks, rocky nature trails, walks on the beach, or fast-paced sporting events. The nervous system must process many aspects of the environment to produce an appropriate motor output in order to maintain balance on two legs. We have previously identified three balance mechanisms that young healthy adults use to maintain balance while walking: 1) The ankle roll mechanism, a modulation of ankle inversion/eversion; 2) The foot placement mechanism, a shift of the swing foot placement; and 3) The push-off mechanism, a modulation of the ankle plantarflexion angle during double stance. We know that these mechanisms are interdependent and can be influenced by internal factors such as the phase of the gait cycle and walking cadence. Here we seek to determine whether there are changes in neural control of balance when walking in the presence of environmental constraints. Subjects walked on a selfpaced treadmill while immersed in a virtual environment that provides three different colored pathways. Subjects were instructed not to step in the No-Step Zone, which appeared either on the right or left side of the subject. While walking, subjects received balance perturbations in the form of galvanic vestibular stimulation, providing the sensation of falling sideways, either toward the No-Step zone or toward the Neutral zone on the other side. The results indicate that the use of the balance mechanisms are subtly altered depending on whether the perceived fall is toward the No-Step or the Neutral zone. This experiment provides further evidence that the balance control system during walking is extremely flexible, recruiting multiple mechanisms at different times in the gait cycle to adapt to environmental constraints.

scholarly journals Walking cadence affects the recruitment of the medial-lateral balance mechanisms

2019 ◽  
Author(s):  
Tyler Fettrow ◽  
Hendrik Reimann ◽  
David Grenet ◽  
Jeremy Crenshaw ◽  
Jill Higginson ◽  
...  
Keyword(s):  
Older Adults ◽  
Virtual Reality ◽  
Neural Control ◽  
Gait Cycle ◽  
Balance Control ◽  
Vestibular Stimulation ◽  
Lateral Ankle ◽  
Foot Placement ◽  
Ankle Inversion ◽  
Gait Characteristics

AbstractWe have previously identified three balance mechanisms that young healthy adults use to maintain balance while walking. The three mechanisms are: 1) The lateral ankle mechanism, an active modulation of ankle inversion/eversion in stance; 2) The foot placement mechanism, an active shift of the swing foot placement; and 3) The push-off mechanism, an active modulation of the ankle plantarflexion angle during double stance. Here we seek to determine whether there are changes in neural control of balance when walking at different cadences and speeds. Twenty-one healthy young adults walked on a self-paced treadmill while immersed in a 3D virtual reality cave, and periodically received balance perturbations (bipolar galvanic vestibular stimulation) eliciting a perceived fall to the side. Subjects were instructed to match two cadences specified by a metronome, 110bpm (High) and 80bpm (Low), which led to faster and slower gait speeds, respectively. The results indicate that subjects altered the use of the balance mechanisms at different cadences. The lateral ankle mechanism was used more in the Low condition, while the foot placement mechanism was used more in the High condition. There was no difference in the use of the push-off mechanism between cadence conditions. These results suggest that neural control of balance is altered when gait characteristics such as cadence change, suggesting a flexible balance response that is sensitive to the constraints of the gait cycle. We speculate that the use of the balance mechanisms may be a factor resulting in well-known characteristics of gait in populations with compromised balance control, such as slower gait speed in older adults or higher cadence in people with Parkinson’s disease.

scholarly journals Cortical reorganization to improve dynamic balance control with error amplification feedback

2022 ◽  
Vol 19 (1) ◽  
Author(s):  
Yi-Ching Chen ◽  
Yi-Ying Tsai ◽  
Gwo-Ching Chang ◽  
Ing-Shiou Hwang
Keyword(s):  
Visual Feedback ◽  
Neural Control ◽  
Balance Control ◽  
Dynamic Balance ◽  
Cortical Reorganization ◽  
Phase Lag ◽  
Behavioral Strategies ◽  
Beta Band ◽  
Error Amplification ◽  
The Right

Abstract Background Error amplification (EA), virtually magnify task errors in visual feedback, is a potential neurocognitive approach to facilitate motor performance. With regional activities and inter-regional connectivity of electroencephalography (EEG), this study investigated underlying cortical mechanisms associated with improvement of postural balance using EA. Methods Eighteen healthy young participants maintained postural stability on a stabilometer, guided by two visual feedbacks (error amplification (EA) vs. real error (RE)), while stabilometer plate movement and scalp EEG were recorded. Plate dynamics, including root mean square (RMS), sample entropy (SampEn), and mean frequency (MF) were used to characterize behavioral strategies. Regional cortical activity and inter-regional connectivity of EEG sub-bands were characterized to infer neural control with relative power and phase-lag index (PLI), respectively. Results In contrast to RE, EA magnified the errors in the visual feedback to twice its size during stabilometer stance. The results showed that EA led to smaller RMS of postural fluctuations with greater SampEn and MF than RE did. Compared with RE, EA altered cortical organizations with greater regional powers in the mid-frontal cluster (theta, 4–7 Hz), occipital cluster (alpha, 8–12 Hz), and left temporal cluster (beta, 13–35 Hz). In terms of the phase-lag index of EEG between electrode pairs, EA significantly reduced long-range prefrontal-parietal and prefrontal-occipital connectivity of the alpha/beta bands, and the right tempo-parietal connectivity of the theta/alpha bands. Alternatively, EA augmented the fronto-centro-parietal connectivity of the theta/alpha bands, along with the right temporo-frontal and temporo-parietal connectivity of the beta band. Conclusion EA alters postural strategies to improve stance stability on a stabilometer with visual feedback, attributable to enhanced error processing and attentional release for target localization. This study provides supporting neural correlates for the use of virtual reality with EA during balance training.

scholarly journals Greater exposure to repetitive subconcussive head impacts is associated with vestibular dysfunction and balance impairments during walking

Neurology ◽  
2018 ◽  
Vol 91 (23 Supplement 1) ◽  
pp. S27.2-S27
Author(s):  
Fernando Santos ◽  
Jaclyn B Caccese ◽  
Mariana Gongora ◽  
Ian Sotnek ◽  
Elizabeth Kaye ◽  
...  
Keyword(s):  
Center Of Pressure ◽  
Balance Control ◽  
Center Of Mass ◽  
Vestibular Stimulation ◽  
Vestibular Dysfunction ◽  
Foot Placement ◽  
Head Impacts ◽  
Eyes Closed ◽  
Balance Deficits ◽  
Soccer Heading

Exposure to repetitive subconcussive head impacts (RSHI), specifically soccer heading, is associated with white matter microstructural changes and cognitive performance impairments. However, the effect of soccer heading exposure on vestibular processing and balance control during walking has not been studied. Galvanic vestibular stimulation (GVS) is a tool that can be used to probe the vestibular system during standing and walking. The purpose of this study was to investigate the association of soccer heading with subclinical balance deficits during walking. Twenty adult amateur soccer players (10 males and 10 females, 22.3 ± 4.5 years, 170.5 ± 9.8 cm, 70.0 ± 10.5 kg) walked along a foam walkway with the eyes closed under 2 conditions: with GVS (∼40 trials) and without GVS (∼40 trials). Outcome measures included mediolateral center-of-mass (COM), center-of-pressure (COP) separation, foot placement, mediolateral ankle modulation, hip adduction, and ankle push off. For each balance mechanism, a GVS response was calculated (GVS, mean [without GVS]). In addition, participants completed a questionnaire, reporting soccer heading exposure over the past year. A linear regression model was used to determine if vestibular processing and balance during walking were related to RSHI exposure. Both foot placement (R2 = 0.324, p = 0.009) and hip adduction (R2 = 0.183, p = 0.50) were predicted by RSHI; whereby, greater exposure to RSHI was associated with greater foot placement and hip adduction responses. However, COM-COP separation (R2 < 0.001, p = 0.927), ankle modulation (R2 = 0.037, p = 0.417), and push off (R2 < 0.001, p = 0.968) were not related to RSHI exposure. Individuals who were exposed to greater RSHI were more perturbed by vestibular stimulation during walking, suggesting that there may be vestibular dysfunction and balance impairments with frequent heading; specifically, individuals with greater exposure to RSHI responded with larger foot placement and hip adduction responses to GVS.

When is Vestibular Information Important During Walking?

2004 ◽  
Vol 92 (3) ◽  
pp. 1269-1275 ◽  
Author(s):  
Leah R. Bent ◽  
J. Timothy Inglis ◽  
Bradford J. McFadyen
Keyword(s):  
Gait Cycle ◽  
Vestibular Stimulation ◽  
Upper Body ◽  
Foot Placement ◽  
Double Support ◽  
Vestibular Information ◽  
Heel Contact ◽  
Somatosensory Input ◽  
Single Support Phase ◽  
Support Phase

Locomotion relies on vision, somatosensory input, and vestibular information. Both vision and somatosensory signals have been shown to be phase dependently modulated during locomotion; however, the regulation of vestibular information has not been investigated in humans. By delivering galvanic vestibular stimulation (GVS) to subjects at either heel contact, mid-stance, or toe-off, it was possible to investigate when vestibular information was important during the gait cycle. The results indicated a difference in the vestibular regulation of upper versus lower body control. Upper body responses to GVS applied at different times did not differ in magnitude for the head ( P = 0.2383), trunk ( P = 0.1473), or pelvis ( P = 0.1732) showing a similar dependence on vestibular information for upper body alignment across the gait cycle. In contrast, foot placement was dependent on the time when stimulation was delivered. Changes in foot placement were significantly larger at heel contact (during the double support phase) than when stimulation was delivered at mid-stance (in the single support phase of the gait cycle; P = 0.0193). These latter results demonstrate, for the first time, evidence of phase-dependent modulation of vestibular information during human walking.

Functional anatomy of the vagal innervation of the cervical trachea of the dog

2000 ◽  
Vol 89 (1) ◽  
pp. 139-142 ◽  
Author(s):  
Robert L. Coon ◽  
Patrick J. Mueller ◽  
Philip S. Clifford
Keyword(s):  
Smooth Muscle ◽  
Vagus Nerve ◽  
Neural Control ◽  
Muscle Tone ◽  
Cuff Pressure ◽  
Vagal Innervation ◽  
Cervical Trachea ◽  
The Right ◽  
Left Vagus ◽  
Stimulation Of

The canine cervical trachea has been used for numerous studies regarding the neural control of tracheal smooth muscle. The purpose of the present study was to determine whether there is lateral dominance by either the left or right vagal innervation of the canine cervical trachea. In anesthetized dogs, pressure in the cuff of the endotracheal tube was used as an index of smooth muscle tone in the trachea. After establishment of tracheal tone, as indicated by increased cuff pressure, either the right or left vagus nerve was sectioned followed by section of the contralateral vagus. Sectioning the right vagus first resulted in total loss of tone in the cervical trachea, whereas sectioning the left vagus first produced either a partial or no decrease in tracheal tone. After bilateral section of the vagi, cuff pressure was recorded during electrical stimulation of the rostral end of the right or left vagus. At the maximum current strength used, stimulation of the left vagus produced tracheal constriction that averaged 28.5% of the response to stimulation of the right vagus (9.0 ± 1.8 and 31.6 ± 2.5 mmHg, respectively). In conclusion, the musculature of cervical trachea in the dog appears to be predominantly controlled by vagal efferents in the right vagus nerve.

Probing the human vestibular system with galvanic stimulation

2004 ◽  
Vol 96 (6) ◽  
pp. 2301-2316 ◽  
Author(s):  
Richard C. Fitzpatrick ◽  
Brian L. Day
Keyword(s):  
Balance Control ◽  
Semicircular Canals ◽  
Vestibular Nuclei ◽  
Vestibular Stimulation ◽  
Otolith Organs ◽  
Sources Of Information ◽  
Electrophysiological Studies ◽  
Human Balance ◽  
Cortical Inputs ◽  
Vestibular Organs

Galvanic vestibular stimulation (GVS) is a simple, safe, and specific way to elicit vestibular reflexes. Yet, despite a long history, it has only recently found popularity as a research tool and is rarely used clinically. The obstacle to advancing and exploiting GVS is that we cannot interpret the evoked responses with certainty because we do not understand how the stimulus acts as an input to the system. This paper examines the electrophysiology and anatomy of the vestibular organs and the effects of GVS on human balance control and develops a model that explains the observed balance responses. These responses are large and highly organized over all body segments and adapt to postural and balance requirements. To achieve this, neurons in the vestibular nuclei receive convergent signals from all vestibular receptors and somatosensory and cortical inputs. GVS sway responses are affected by other sources of information about balance but can appear as the sum of otolithic and semicircular canal responses. Electrophysiological studies showing similar activation of primary afferents from the otolith organs and canals and their convergence in the vestibular nuclei support this. On the basis of the morphology of the cristae and the alignment of the semicircular canals in the skull, rotational vectors calculated for every mode of GVS agree with the observed sway. However, vector summation of signals from all utricular afferents does not explain the observed sway. Thus we propose the hypothesis that the otolithic component of the balance response originates from only the pars medialis of the utricular macula.

The Influence of Profession on Functional Ankle Stability in Musicians

2010 ◽  
Vol 25 (1) ◽  
pp. 22-28 ◽  
Author(s):  
Susanne Rein ◽  
Tobias Fabian ◽  
Hans Zwipp ◽  
Jan Heineck ◽  
Stephan Weindel
Keyword(s):  
Reaction Time ◽  
Ankle Joint ◽  
Postural Balance ◽  
Balance Control ◽  
Ankle Sprains ◽  
Exact Test ◽  
Work Related ◽  
Ankle Stability ◽  
Ankle Joints ◽  
The Right

OBJECTIVE: The aim of this study was to examine the influence of extensive work-related use of the feet on functional ankle stability among musicians. METHODS: Thirty professional organists were compared to professional pianists and controls. All participants completed a questionnaire. Range of motion (ROM), peroneal reaction time, and positional sense tests of the ankle were measured. The postural balance control was investigated with the Biodex Stability System for the stable level 8 and unstable level 2. Statistical analysis was done with the Kruskal-Wallis test, Mann-Whitney test with Bonferroni-Holm correction, and Fisher’s exact test. RESULTS: Nine of 30 organists compared to 5 of 30 pianists and controls reported ankle sprains in their medical history. Pianists had a significant increased flexion of both ankle joints compared to organists (p≤0.01) and increased flexion of the right ankle joint compared to controls (p=0.02). The positional sense test and postural balance control showed no significant differences among groups. The peroneal reaction time of the right peroneus longus muscle was significantly increased in pianists compared to controls (p=0.008). CONCLUSIONS: Organists have shown a high incidence of ankle sprains. Despite their extensive work-related use of the ankle joints, organists have neither increased functional ankle stability nor increased ROM of their ankle joints in comparison to controls. Pianists have increased flexion of the ankle joint, perhaps due to the exclusive motion of extension and flexion while using the pedals. To minimize injuries of the ankle and improve functional ankle stability as well as balance control, proprioceptive exercises of the ankle in daily training programs are recommended.

Classification of Landscape Sensitivity in the Territory of Cremona

2013 ◽  
Vol 4 (3) ◽  
pp. 63-79 ◽  
Author(s):  
Pier Luigi Paolillo ◽  
Umberto Baresi ◽  
Roberto Bisceglie
Keyword(s):  
Spatial Information ◽  
Analytical Techniques ◽  
Urban System ◽  
Multidimensional Analysis ◽  
Environmental Constraints ◽  
Synthetic Indicators ◽  
Territorial Planning ◽  
Landscape Sensitivity ◽  
The Right

Centrality of landscape, in territorial planning, has been influencing for years, the testing of innovative analytical techniques aimed to gather peculiarities of urban and suburban context. The advent of Spatial Information System created the possibility to produce more detailed studies analyzing a lot of information dealing with territorial phenomena of crucial importance in spatial planning. The development of analytical systems based on multidimensional analysis may represent the right way to synthesize different phenomena that interact locally, in order to obtain the intrinsic sensitivity of a specific landscape as a result. In the case of Cremona Urban Variant, the production of thematic maps has allowed the construction of six synthetic indicators, dealing with specific aspects of Cremona landscape. The indicators are: i) insularisation of non – built spaces, ii) morphological / structural values, iii) perceptual landscape aspects, iv) permanence of urban system, v) degree of imperativeness of environmental constraints, vi) integrity of land use.

scholarly journals Structural and environmental constraints on reduction of paired appendages among vertebrates

2019 ◽  
Author(s):  
Loredana Macaluso ◽  
Giorgio Carnevale ◽  
Raffaello Casu ◽  
Daniel Pietrocola ◽  
Andrea Villa ◽  
...  
Keyword(s):  
Limb Loss ◽  
Appendicular Skeleton ◽  
Environmental Constraints ◽  
Structural Constraints ◽  
Teleost Fishes ◽  
Complex Environments ◽  
Complex Environment ◽  
Pectoral Fins ◽  
Squamate Reptiles ◽  
Complex Habitat

Abstract Burrowing habits or complex environments have generally been considered as potential drivers acting on reduction and loss of the appendicular skeleton among vertebrates. Herein, we suggest that this might be the case for lissamphibians and squamates, but that fin loss in fishes is usually prevented by important structural constraints, because pectoral fins are commonly used to control rolling and pitching. We provide an overview of the distribution of paired appendage reduction across vertebrates while examining the ecological affinities of finless and limbless clades. We analysed the correlation between lifestyle and fin or limb loss using the discrete comparative analysis. The resulting Bayesian factors indicate strong evidence of correlation between: (1) pectoral-fin loss and coexistence of anguilliform elongation and burrowing habits or complex habitat in teleost fishes; and (2) limb loss and a burrowing or grass-swimming lifestyle in squamate reptiles and lissamphibians. These correlations suggest that a complex environment or a fossorial habit is a driving force leading to appendage loss. The only style of locomotion that is functional even in the absence of paired appendages is the undulatory one, which is typical of all elongated reptiles and lissamphibians, but certainly less common in teleost fishes.

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