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Xie H, Liang M, Mo Y, Schmidt C, Wang C, Chien JH. Comparison Between Effects of Galvanic and Vibration-Based Vestibular Stimulation on Postural Control and Gait Performance in Healthy Participants: A Systematic Review of Cross-Sectional Studies. Ann Biomed Eng 2024; 52:757-793. [PMID: 38148425 DOI: 10.1007/s10439-023-03425-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Accepted: 12/08/2023] [Indexed: 12/28/2023]
Abstract
Electricity and vibration were two commonly used physical agents to provide vestibular stimulation in previous studies. This study aimed to systematically review the effects of galvanic (GVS) and vibration-based vestibular stimulation (VVS) on gait performance and postural control in healthy participants. Five bioscience and engineering databases, including MEDLINE via PubMed, CINAHL via EBSCO, Cochrane Library, Scopus, and Embase, were searched until March 19th, 2023. Studies published between 2000 and 2023 in English involving GVS and VVS related to gait performance and postural control were included. The procedure was followed via the Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines. The methodological quality of included studies was assessed using the NIH study quality assessment tool for observational cohort and cross-sectional studies. A total of 55 cross-sectional studies met the inclusion criteria and were included in this study. Five studies were good-quality while 49 were moderate-quality and 1 was poor-quality. There were 50 included studies involving GVS and 5 included studies involving VVS. GVS and VVS utilized different physical agents to provide vestibular stimulation and demonstrated similar effects on vestibular perception. Supra-threshold GVS and VVS produced vestibular perturbation that impaired gait performance and postural control, while sub-threshold GVS and VVS induced stochastic resonance phenomenon that led to an improvement. Bilateral vestibular stimulation demonstrated a greater effect on gait and posture than unilateral vestibular stimulation. Compared to GVS, VVS had the characteristics of better tolerance and fewer side effects, which may substitute GVS to provide more acceptable vestibular stimulation.
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Affiliation(s)
- Haoyu Xie
- Department of Rehabilitation Medicine, The First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, Guangdong, China
| | - Meizhen Liang
- Department of Rehabilitation Medicine, The First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, Guangdong, China
| | - Yujia Mo
- Chan Division of Occupational Science and Occupational Therapy, University of Southern California, Los Angeles, CA, USA
| | - Cindy Schmidt
- Leon S. McGoogan Health Sciences Library, University of Nebraska Medical Center, Omaha, NE, USA
| | - Chuhuai Wang
- Department of Rehabilitation Medicine, The First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, Guangdong, China.
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2
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Modi AD, Parekh A, Patel ZH. Methods for evaluating gait associated dynamic balance and coordination in rodents. Behav Brain Res 2024; 456:114695. [PMID: 37783346 DOI: 10.1016/j.bbr.2023.114695] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Revised: 09/29/2023] [Accepted: 09/30/2023] [Indexed: 10/04/2023]
Abstract
Balance is the dynamic and unconscious control of the body's centre of mass to maintain postural equilibrium. Regulated by the vestibular system, head movement and acceleration are processed by the brain to adjust joints. Several conditions result in a loss of balance, including Alzheimer's Disease, Parkinson's Disease, Menière's Disease and cervical spondylosis, all of which are caused by damage to certain parts of the vestibular pathways. Studies about the impairment of the vestibular system are challenging to carry out in human trials due to smaller study sizes limiting applications of the results and a lacking understanding of the human balance control mechanism. In contrast, more controlled research can be performed in animal studies which have fewer confounding factors than human models and allow specific conditions that affect balance to be replicated. Balance control can be studied using rodent balance-related behavioural tests after spinal or brain lesions, such as the Basso, Beattie and Bresnahan (BBB) Locomotor Scale, Foot Fault Scoring System, Ledged Beam Test, Beam Walking Test, and Ladder Beam Test, which are discussed in this review article along with their advantages and disadvantages. These tests can be performed in preclinical rodent models of femoral nerve injury, stroke, spinal cord injury and neurodegenerative diseases.
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Affiliation(s)
- Akshat D Modi
- Department of Biological Sciences, University of Toronto, Scarborough, Ontario M1C 1A4, Canada; Department of Genetics and Development, Krembil Research Institute, Toronto, Ontario M5T 0S8, Canada.
| | - Anavi Parekh
- Department of Neuroscience, University of Toronto, Toronto, Ontario M5S 1A1, Canada
| | - Zeenal H Patel
- Department of Biological Sciences, University of Toronto, Scarborough, Ontario M1C 1A4, Canada; Department of Biochemistry, University of Toronto, Scarborough, Ontario M1C 1A4, Canada
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3
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Zanchi S, Cuturi LF, Sandini G, Gori M, Ferrè ER. Vestibular contribution to spatial encoding. Eur J Neurosci 2023; 58:4034-4042. [PMID: 37688501 DOI: 10.1111/ejn.16146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Revised: 08/23/2023] [Accepted: 08/25/2023] [Indexed: 09/11/2023]
Abstract
Determining the spatial relation between objects and our location in the surroundings is essential for survival. Vestibular inputs provide key information about the position and movement of our head in the three-dimensional space, contributing to spatial navigation. Yet, their role in encoding spatial localisation of environmental targets remains to be fully understood. We probed the accuracy and precision of healthy participants' representations of environmental space by measuring their ability to encode the spatial location of visual targets (Experiment 1). Participants were asked to detect a visual light and then walk towards it. Vestibular signalling was artificially disrupted using stochastic galvanic vestibular stimulation (sGVS) applied selectively during encoding targets' location. sGVS impaired the accuracy and precision of locating the environmental visual targets. Importantly, this effect was specific to the visual modality. The location of acoustic targets was not influenced by vestibular alterations (Experiment 2). Our findings indicate that the vestibular system plays a role in localising visual targets in the surrounding environment, suggesting a crucial functional interaction between vestibular and visual signals for the encoding of the spatial relationship between our body position and the surrounding objects.
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Affiliation(s)
- Silvia Zanchi
- Unit of Visually Impaired People, Italian Institute of Technology, Genoa, Italy
- Department of Psychological Sciences, Birkbeck, University of London, London, UK
| | - Luigi F Cuturi
- Unit of Visually Impaired People, Italian Institute of Technology, Genoa, Italy
- Department of Cognitive Sciences, Psychology, Education and Cultural Studies, University of Messina, Messina, Italy
| | - Giulio Sandini
- Robotics Brain and Cognitive Sciences, Italian Institute of Technology, Genoa, Italy
| | - Monica Gori
- Unit of Visually Impaired People, Italian Institute of Technology, Genoa, Italy
| | - Elisa R Ferrè
- Department of Psychological Sciences, Birkbeck, University of London, London, UK
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Abbariki F, Mikhail Y, Hamadjida A, Charron J, Mac-Thiong JM, Barthélemy D. Effect of galvanic vestibular stimulation applied at the onset of stance on muscular activity and gait cycle duration in healthy individuals. Front Neural Circuits 2023; 16:1065647. [PMID: 36845254 PMCID: PMC9946991 DOI: 10.3389/fncir.2022.1065647] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Accepted: 12/28/2022] [Indexed: 02/11/2023] Open
Abstract
Locomotion requires the complex involvement of the spinal and supraspinal systems. So far, the role of vestibular input in gait has been assessed mainly with respect to gait stability. The noninvasive technique of galvanic vestibular stimulation (GVS) has been reported to decrease gait variability and increase gait speed, but the extent of its effect on spatiotemporal gait parameters is not fully known. Objective: Characterize vestibular responses during gait and determine the influence of GVS on cycle duration in healthy young participants. Methods: Fifteen right-handed individuals participated in the study. Electromyography (EMG) recordings of the bilateral soleus (SOL) and tibialis anterior muscles (TA) were performed. First, to determine stimulation intensity, an accelerometer placed on the vertex recorded the amplitude of the head tilts evoked by the GVS (1-4 mA, 200 ms) to establish a motor threshold (T). Second, while participants walked on a treadmill, GVS was applied at the onset of the stance phase during the treadmill gait with an intensity of 1 and 1.5 T with the cathode behind the right (RCathode) or left ear (LCathode). EMG traces were rectified, averaged (n = 30 stimuli), and analyzed. Latency, duration, and amplitude of vestibular responses as well as the mean duration of the gait cycles were measured. Results: GVS mainly induced long-latency responses in the right SOL, right TA and left TA. Only short-latency responses were triggered in the left SOL. Responses in the right SOL, left SOL and left TA were polarity dependent, being facilitatory with RCathode and inhibitory with LCathode, whereas responses in the right TA remained facilitatory regardless of the polarity. With the RCathode configuration, the stimulated cycle was prolonged compared with the control cycle at both 1 and 1.5 T, due to prolonged left SOL and TA EMG bursts, but no change was observed in right SOL and TA. With LCathode, GVS did not modify the cycle duration. Conclusion: During gait, a brief, low-intensity GVS pulse delivered at the right stance onset induced mainly long-latency polarity-dependent responses. Furthermore, a RCathode configuration increased the duration of the stimulated gait cycle by prolonging EMG activity on the anodic side. A similar approach could be explored to influence gait symmetry in individuals with neurological impairment.
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Affiliation(s)
- Faezeh Abbariki
- School of Rehabilitation, Université de Montréal, Montreal, QC, Canada
- Centre for Interdisciplinary Research in Rehabilitation of Greater Montreal (CRIR) and Centre Intégré Universitaire en Santé et Services Sociaux (CIUSSS) du Centre-Sud-de-l’Île-de-Montréal, Montreal, QC, Canada
| | - Youstina Mikhail
- Faculty of Medicine, Université de Montréal, Montreal, QC, Canada
| | - Adjia Hamadjida
- Faculty of Medicine, Université de Montréal, Montreal, QC, Canada
- Department of Live Science, Higher Teacher Training College of Bertoua, University of Bertoua, Bertoua, Cameroon
| | - Jonathan Charron
- Faculty of Medicine, Université de Montréal, Montreal, QC, Canada
| | - Jean-Marc Mac-Thiong
- Faculty of Medicine, Université de Montréal, Montreal, QC, Canada
- Centre Intégré Universitaire en Santé et Services Sociaux du nord de l’île de Montréal (CIUSSS NIM), Hôpital du Sacré-coeur de Montréal (HSCM), Montréal, QC, Canada
| | - Dorothy Barthélemy
- School of Rehabilitation, Université de Montréal, Montreal, QC, Canada
- Centre for Interdisciplinary Research in Rehabilitation of Greater Montreal (CRIR) and Centre Intégré Universitaire en Santé et Services Sociaux (CIUSSS) du Centre-Sud-de-l’Île-de-Montréal, Montreal, QC, Canada
- Centre Intégré Universitaire en Santé et Services Sociaux du nord de l’île de Montréal (CIUSSS NIM), Hôpital du Sacré-coeur de Montréal (HSCM), Montréal, QC, Canada
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Nguyen TT, Kang JJ, Oh SY. Thresholds for vestibular and cutaneous perception and oculomotor response induced by galvanic vestibular stimulation. Front Neurol 2022; 13:955088. [PMID: 36034303 PMCID: PMC9413160 DOI: 10.3389/fneur.2022.955088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2022] [Accepted: 07/18/2022] [Indexed: 12/04/2022] Open
Abstract
Objectives In this study, the specific threshold intensities and response characteristics of galvanic vestibular stimulation (GVS) on vestibular (conscious) and cutaneous (detrimental) perception as well as oculomotor nystagmus (reflex) were determined. Methods The threshold intensities for vestibular and cutaneous perception and oculomotor response induced by GVS were determined in 25 right-handed healthy subjects (32.6 ± 7.2 years of age; 56% female). The subjects were seated upright, and eye movements were recorded while a direct GVS current was applied with paradigms of cathode on the right and anode on the left (CRAL) and also cathode on the left and anode on the right (CLAR). Results Subjects experienced dizziness, sense of spinning, or fall tendency, which was more frequently directed to the cathode (76%) than the anode (24%, p < 0.001, chi-square one-variable test) at mean current greater than 0.98 ± 0.29 mA (mean vestibular threshold). The current also triggered a more frequent mild tingling sensation at the cathode (56%) than the anode (30%) or on both sides (14%; p = 0.001, chi-square one-variable test) when above the mean cutaneous threshold of 0.9 ± 0.29 mA. Above the mean oculomotor threshold of 1.61 ± 0.35 mA, combined horizontal and torsional nystagmus was more frequent toward the cathode (86%) than toward the anode (p < 0.001, chi-square one-variable test). The mean oculomotor threshold was significantly higher than both the vestibular (p < 0.001, Mann–Whitney U-test) and cutaneous (p < 0.001, Mann–Whitney U-test) thresholds, which were comparable (p = 0.317, Mann–Whitney U-test). There was no significant disparity in these specific thresholds between the two GVS paradigms. The vestibular threshold was significantly higher in males than in females [1 (0.5–1.25) mA vs. 0.75 (0.625–1.125) mA, Z = −2.241, p = 0.025, Mann–Whitney U-test]. However, the thresholds of cutaneous perception and oculomotor response did not differ by sex. Conclusion The findings indicate that thresholds for vestibular and somatosensory perception are lower than the oculomotor threshold. Therefore, a strategy to reduce GVS current intensity to the level of vestibular or somatosensory perception threshold could elicit beneficial vestibular effects while avoiding undesirable effects such as oculomotor consequences.
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Affiliation(s)
- Thanh Tin Nguyen
- Jeonbuk National University College of Medicine, Jeonju, South Korea
- Department of Neurology, Jeonbuk National University Hospital and School of Medicine, Jeonju, South Korea
- Department of Pharmacology, Hue University of Medicine and Pharmacy, Hue University, Hue, Vietnam
| | - Jin-Ju Kang
- Department of Neurology, Jeonbuk National University Hospital and School of Medicine, Jeonju, South Korea
- Research Institute of Clinical Medicine of Jeonbuk National University-Biomedical Research Institute of Jeonbuk National University Hospital, Jeonju, South Korea
| | - Sun-Young Oh
- Jeonbuk National University College of Medicine, Jeonju, South Korea
- Department of Neurology, Jeonbuk National University Hospital and School of Medicine, Jeonju, South Korea
- Research Institute of Clinical Medicine of Jeonbuk National University-Biomedical Research Institute of Jeonbuk National University Hospital, Jeonju, South Korea
- *Correspondence: Sun-Young Oh
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Mikhail Y, Charron J, Mac-Thiong JM, Barthélemy D. Assessing head acceleration to identify a motor threshold to galvanic vestibular stimulation. J Neurophysiol 2021; 125:2191-2205. [PMID: 33881904 DOI: 10.1152/jn.00254.2020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Galvanic vestibular stimulation (GVS) is used to assess vestibular system function, but vestibulospinal responses can exhibit variability depending on protocols or intensities used. Here, we measured head acceleration in healthy subjects to identify an objective motor threshold on which to base GVS intensity when assessing standing postural responses. Thirteen healthy right-handed subjects stood on a force platform, eyes closed, and head facing forward. An accelerometer was placed on the vertex to detect head acceleration, and electromyography activity of the right soleus was recorded. GVS (200 ms; current steps 0.5, from 1 mA to 4 mA) was applied in a binaural and bipolar configuration. 1) GVS induced a biphasic accelerometer response at a latency of 15 ms. Based on response amplitude, we constructed a recruitment curve for all participants and determined the motor threshold. In parallel, the method of limits was used to devise a more rapid approach to determine motor threshold. 2) We observed significant differences between motor threshold based on a recruitment curve and all perceptual thresholds reported either by the subject (sensation of movement) or a standing experimenter observing the participant (perception of movement). No significant difference was observed between the motor threshold based on the method of limits and perceptual thresholds of movement. 3) Using orthogonal polynomial contrasts, we observed a linear progression between multiples of the objective motor threshold (0.5, 0.75, 1, 1.5× motor threshold) and the 95% confidence ellipse area, the first peak of center of pressure displacement velocity, and the short and medium latency responses in the soleus. Hence, an objective motor threshold for GVS based on head acceleration was identified in standing participants and a recruitment curve could be constructed for all participants. These novel approaches could enable better understanding of changes in the vestibular system in different conditions or over time.NEW & NOTEWORTHY Galvanic vestibular stimulation (GVS) has been used to assess the vestibular system, but the significant interindividual variability in the responses makes it difficult to quantitatively compare them between individuals or conditions. Using an accelerometer to quantify head movement induced by GVS, we were able to determine an objective motor threshold and construct a recruitment curve for all participants. These methods could help assess changes in the vestibular system under different conditions.
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Affiliation(s)
- Youstina Mikhail
- School of Rehabilitation, Université de Montréal, Montreal, Canada.,Centre for Interdisciplinary Research in Rehabilitation of Greater Montreal, Centres Intégrés Universitaires de Santé et de Services Sociaux Centre-Sud, Institut Universitaire sur la Réadaptation en Déficience Physique de Montréal, Montreal, Canada
| | - Jonathan Charron
- Centre for Interdisciplinary Research in Rehabilitation of Greater Montreal, Centres Intégrés Universitaires de Santé et de Services Sociaux Centre-Sud, Institut Universitaire sur la Réadaptation en Déficience Physique de Montréal, Montreal, Canada.,Department of Biological Sciences, Université de Montréal, Montreal, Canada
| | - Jean-Marc Mac-Thiong
- Department of Surgery, Université de Montréal, Montreal, Canada.,Centres Intégrés Universitaires de Santé et de Services Sociaux du Nord-de-l'Île-de-Montréal, Hôpital du Sacré-Coeur-de-Montréal, Montreal, Canada
| | - Dorothy Barthélemy
- School of Rehabilitation, Université de Montréal, Montreal, Canada.,Centre for Interdisciplinary Research in Rehabilitation of Greater Montreal, Centres Intégrés Universitaires de Santé et de Services Sociaux Centre-Sud, Institut Universitaire sur la Réadaptation en Déficience Physique de Montréal, Montreal, Canada.,Centres Intégrés Universitaires de Santé et de Services Sociaux du Nord-de-l'Île-de-Montréal, Hôpital du Sacré-Coeur-de-Montréal, Montreal, Canada
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Akay T, Murray AJ. Relative Contribution of Proprioceptive and Vestibular Sensory Systems to Locomotion: Opportunities for Discovery in the Age of Molecular Science. Int J Mol Sci 2021; 22:1467. [PMID: 33540567 PMCID: PMC7867206 DOI: 10.3390/ijms22031467] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Revised: 01/20/2021] [Accepted: 01/26/2021] [Indexed: 12/29/2022] Open
Abstract
Locomotion is a fundamental animal behavior required for survival and has been the subject of neuroscience research for centuries. In terrestrial mammals, the rhythmic and coordinated leg movements during locomotion are controlled by a combination of interconnected neurons in the spinal cord, referred as to the central pattern generator, and sensory feedback from the segmental somatosensory system and supraspinal centers such as the vestibular system. How segmental somatosensory and the vestibular systems work in parallel to enable terrestrial mammals to locomote in a natural environment is still relatively obscure. In this review, we first briefly describe what is known about how the two sensory systems control locomotion and use this information to formulate a hypothesis that the weight of the role of segmental feedback is less important at slower speeds but increases at higher speeds, whereas the weight of the role of vestibular system has the opposite relation. The new avenues presented by the latest developments in molecular sciences using the mouse as the model system allow the direct testing of the hypothesis.
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Affiliation(s)
- Turgay Akay
- Atlantic Mobility Action Project, Brain Repair Centre, Department of Medical Neuroscience, Life Science Research Institute, Dalhousie University, Halifax, NS B3H 4R2, Canada
| | - Andrew J. Murray
- Sainsbury Wellcome Centre for Neural Circuits and Behaviour, University College London, London W1T 4JG, UK
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8
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Guillaud E, Faure C, Doat E, Bouyer LJ, Guehl D, Cazalets JR. Ancestral persistence of vestibulospinal reflexes in axial muscles in humans. J Neurophysiol 2020; 123:2010-2023. [PMID: 32319843 DOI: 10.1152/jn.00421.2019] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Most studies addressing the role of vestibulospinal reflexes in balance maintenance have mainly focused on responses in the lower limbs, while limited attention has been paid to the output in trunk and back muscles. To address this issue, we tested whether electromyographic (EMG) responses to galvanic vestibular stimulations (GVS) were modulated similarly in back and leg muscles, in situations where the leg muscle responses to GVS are known to be attenuated. Body sway and surface EMG signals were recorded in the paraspinal and limb muscles of humans (n = 19) under three complementary conditions. During treadmill locomotion, EMG responses in the lower limbs were observed only during stance, whereas responses in trunk muscles were observed during all phases of the locomotor cycle. During upright standing, a slight head contact abolished the responses in the lower limbs, while the responses remained present in back muscles. Similarly, during parabolic flight-induced microgravity, EMG responses in lower limb muscles were suppressed but remained in axial muscles despite the abolished gravitational otolithic drive. Our results suggest a differentiated control of axial and appendicular muscles when a perturbation is detected by vestibular inputs. The persistence and low modulation of axial muscle responses suggests that a hard-wired reflex is functionally efficient to maintain posture. By contrast, the ankle responses to GVS occur only in balance tasks when proprioceptive feedback is congruent. This study using GVS in microgravity is the first to present an approach delineating feedforward vestibular control in unconstrained environment.NEW & NOTEWORTHY This study addresses the extent of conservation of trunk muscle control in humans. Results show that galvanic vestibular stimulation-evoked vestibular responses in trunk muscles remain strong in conditions where leg muscle responses are downmodulated (walking, standing, microgravity). This suggests a phylogenetically conserved blueprint of sensorimotor organization, with strongly hardwired vestibulospinal inputs to axial motoneurons and a higher degree of flexibility in the later emerging limb control system.
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Affiliation(s)
- Etienne Guillaud
- Institut de Neurosciences Cognitives et Intégratives d'Aquitaine, Université de Bordeaux, CNRS UMR 5287, Bordeaux, France
| | - Céline Faure
- Institut de Neurosciences Cognitives et Intégratives d'Aquitaine, Université de Bordeaux, CNRS UMR 5287, Bordeaux, France.,Center for Interdisciplinary Research in Rehabilitation and Social Integration (CIRRIS), Faculty of Medicine, Université Laval, Quebec City, Quebec, Canada
| | - Emilie Doat
- Institut de Neurosciences Cognitives et Intégratives d'Aquitaine, Université de Bordeaux, CNRS UMR 5287, Bordeaux, France
| | - Laurent J Bouyer
- Center for Interdisciplinary Research in Rehabilitation and Social Integration (CIRRIS), Faculty of Medicine, Université Laval, Quebec City, Quebec, Canada
| | - Dominique Guehl
- CHU de Bordeaux, Service d'explorations fonctionnelles du système nerveux, Bordeaux, France
| | - Jean-René Cazalets
- Institut de Neurosciences Cognitives et Intégratives d'Aquitaine, Université de Bordeaux, CNRS UMR 5287, Bordeaux, France
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Cornwell T, Woodward J, Wu M, Jackson B, Souza P, Siegel J, Dhar S, Gordon KE. Walking With Ears: Altered Auditory Feedback Impacts Gait Step Length in Older Adults. Front Sports Act Living 2020; 2:38. [PMID: 33345030 PMCID: PMC7739652 DOI: 10.3389/fspor.2020.00038] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Accepted: 03/20/2020] [Indexed: 11/13/2022] Open
Abstract
Auditory feedback may provide the nervous system with valuable temporal (e. g., footstep sounds) and spatial (e.g., external reference sounds) information that can assist in the control of upright walking. As such, hearing loss may directly contribute to declines in mobility among older adults. Our purpose was to examine the impact of auditory feedback on the control of walking in older adults. Twenty older adults (65-86 years) with no diagnosed hearing loss walked on a treadmill for three sound conditions: Baseline, Ear Plugs, and White Noise. We hypothesized that in response to reduced temporal auditory feedback during the Ear Plugs and White Noise conditions, participants would adapt shorter and faster steps that are traditionally believed to increase mechanical stability. This hypothesis was not supported. Interestingly, we observed increases in step length (p = 0.047) and step time (p = 0.026) during the Ear Plugs condition vs. Baseline. Taking longer steps during the Ear Plugs condition may have increased ground reaction forces, thus allowing participants to sense footsteps via an occlusion effect. As a follow-up, we performed a Pearson's correlation relating the step length increase during the Ear Plugs condition to participants' scores on a clinical walking balance test, the Functional Gait Assessment. We found a moderate negative relationship (rho = -0.44, p = 0.055), indicating that participants with worse balance made the greatest increases in step length during the Ear Plugs condition. This trend suggests that participants may have actively sought auditory feedback with longer steps, sacrificing a more mechanically stable stepping pattern. We also hypothesized that reduced spatial localization feedback during the Ear Plugs and White Noise conditions would decrease control of center of mass (COM) dynamics, resulting in an increase in lateral COM excursion, lateral margin of stability, and maximum Lyapunov exponent. However, we found no main effects of auditory feedback on these metrics (p = 0.580, p = 0.896, and p = 0.056, respectively). Overall, these results suggest that during a steady-state walking task, healthy older adults can maintain walking control without auditory feedback. However, increases in step length observed during the Ear Plugs condition suggest that temporal auditory cues provide locomotor feedback that becomes increasingly valuable as balance deteriorates with age.
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Affiliation(s)
- Tara Cornwell
- Northwestern University, Biomedical Engineering, Evanston, IL, United States.,Northwestern University, Physical Therapy and Human Movement Sciences, Chicago, IL, United States
| | | | - Mengnan/Mary Wu
- Northwestern University, Physical Therapy and Human Movement Sciences, Chicago, IL, United States
| | - Brennan Jackson
- Northwestern University, Biomedical Engineering, Evanston, IL, United States
| | - Pamela Souza
- Northwestern University, Communication Sciences and Disorders, Evanston, IL, United States
| | - Jonathan Siegel
- Northwestern University, Communication Sciences and Disorders, Evanston, IL, United States
| | - Sumitrajit Dhar
- Northwestern University, Communication Sciences and Disorders, Evanston, IL, United States
| | - Keith E Gordon
- Northwestern University, Physical Therapy and Human Movement Sciences, Chicago, IL, United States.,Edward Hines Jr. VA Hospital, Research Service, Hines, IL, United States
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10
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Fettrow T, Reimann H, Grenet D, Crenshaw J, Higginson J, Jeka J. Walking Cadence Affects the Recruitment of the Medial-Lateral Balance Mechanisms. Front Sports Act Living 2019; 1:40. [PMID: 33344963 PMCID: PMC7739695 DOI: 10.3389/fspor.2019.00040] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Accepted: 09/16/2019] [Indexed: 12/04/2022] Open
Abstract
We 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, 110 bpm (High) and 80 bpm (Low), which in this experiment, 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.
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Affiliation(s)
- Tyler Fettrow
- Department of Kinesiology and Applied Physiology, University of Delaware, Newark, DE, United States
| | - Hendrik Reimann
- Department of Kinesiology and Applied Physiology, University of Delaware, Newark, DE, United States
| | - David Grenet
- Department of Kinesiology and Applied Physiology, University of Delaware, Newark, DE, United States
| | - Jeremy Crenshaw
- Department of Kinesiology and Applied Physiology, University of Delaware, Newark, DE, United States
| | - Jill Higginson
- Department of Mechanical Engineering, University of Delaware, Newark, DE, United States
| | - John Jeka
- Department of Kinesiology and Applied Physiology, University of Delaware, Newark, DE, United States
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Noisy galvanic vestibular stimulation modulates spatial memory in young healthy adults. Sci Rep 2019; 9:9310. [PMID: 31249334 PMCID: PMC6597709 DOI: 10.1038/s41598-019-45757-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Accepted: 06/14/2019] [Indexed: 02/07/2023] Open
Abstract
Hippocampal and striatal circuits play important roles in spatial navigation. These regions integrate environmental information and receive intrinsic afferent inputs from the vestibular system. Past research indicates that galvanic vestibular stimulation (GVS) is a non-invasive technique that modulates hippocampal and striatal activities. There are also evidences for enhanced motor and cognitive functions through GVS. This study extends previous research to investigate whether noisy GVS may improve hippocampal- and striatal-associated aspects of spatial navigation performance. Using a virtual navigation task, we examined effects of noisy GVS on spatial learning and memory. To probe the participants’ sensitivity to hippocampal- or striatal-associated spatial information, we either enlarged the virtual environment’s boundary or replaced an intra-environmental location cue, respectively. Noisy GVS or sham stimulation was applied online during the learning phase in a within-subject crossover design. The results showed that noisy GVS enhanced spatial learning and the sensitivity foremost to hippocampal-dependent spatial information both in males and females. Individual differences in spatial working memory capacity moderated the effects of GVS, with individuals with lower capacity benefitting more from the stimulation. Furthermore, sex-related differences in GVS effects on the two forms of spatial representations may reflect differences between males and females in preferred spatial strategies.
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Toth AJ, Harris LR, Bent LR. Visual feedback is not necessary for recalibrating the vestibular contribution to the dynamic phase of a perturbation recovery response. Exp Brain Res 2019; 237:2185-2196. [PMID: 31214739 DOI: 10.1007/s00221-019-05571-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Accepted: 05/29/2019] [Indexed: 11/26/2022]
Abstract
Our recent work demonstrated that vision can recalibrate the vestibular signal used to re-establish equilibrium following a platform perturbation. Here, we investigate whether vision provided during a platform perturbation can recalibrate the use of vestibular reafference during the dynamic phase of the perturbation response. Dynamic postural responses were examined during a series of five forward perturbations to the body, while galvanic vestibular stimulation (GVS) selectively altered vestibular feedback and LCD occlusion spectacles controlled visual availability. Responses with and without vision were compared. The presence of GVS caused 1.78 ± 0.19 cm of medio-lateral (ML) body motion toward the anode during the initial 3 s of the dynamic postural response across perturbations. This dynamic ML response was attenuated across perturbations 1-3 independent of visual availability, resulting in a significant reduction of ML center of mass and pressure deviations (p < 0.01, ƞ2 = 0.27). That is, the vestibular influence on the ML perturbation response could be altered but vision was not necessary for this adaptation. After removing GVS, the ML response component reversed in direction toward the cathode with a magnitude that was not significantly different to the amount of response attenuation seen when GVS was present (- 0.95 ± 0.19 cm; p = 0.99, ƞ2 = 0.00). This suggested that the use of a GVS-altered vestibular signal during dynamic perturbation responses could be recalibrated, but that visual feedback was likely not responsible. Alternative mechanisms to explain the recalibration process are discussed.
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Affiliation(s)
- Adam J Toth
- Department of Physical Education and Sport Sciences, University of Limerick, Limerick, Ireland.
- Lero, Irish Software Research Centre, University of Limerick, Limerick, Ireland.
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON, Canada.
| | - Laurence R Harris
- Centre for Vision Research, Department of Psychology, York University, Toronto, ON, Canada
| | - Leah R Bent
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON, Canada
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Macuga KL. Multisensory Influences on Driver Steering During Curve Navigation. HUMAN FACTORS 2019; 61:337-347. [PMID: 30320509 DOI: 10.1177/0018720818805898] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
OBJECTIVE The effects of inertial (vestibular and somatosensory) information on driver steering during curve navigation were investigated, using an electric four-wheel mobility vehicle outfitted with a steering wheel and a portable virtual reality system. BACKGROUND When driving, multiple sources of perceptual information are available. Researchers have focused on visual information, which plays a critical role in steering control. However, it is not yet well established how inertial information might contribute. METHODS I biased inertial cues by varying visual/inertial gains (doubled, halved, reversed), as drivers negotiated curving paths, and measured steering accuracy and efficiency. I also assessed whether being exposed to inertial biases had an impact on postbias steering by comparing pre- and posttest session performance measures. RESULTS Doubling or halving inertial cues had little effect on steering performance. Inertial information only disrupted steering when it was reversed with respect to visual information. Over time, the influence of this extreme inertial bias was reduced though not eliminated. Postbias curve navigation performance was not impacted, likely because participants had learned to disregard, rather than integrate, biased inertial cues. CONCLUSION Results suggest that biased inertial information has little influence on curve navigation performance when visual information is available. APPLICATION Though inertial cues may be important for open-loop steering, when visual cues are unavailable, their role in closed-loop steering seems less influential. This has implications for driving simulation and suggests that inertial discrepancies due to limitations in motion-cuing capabilities may not be all that problematic for the simulation of closed-loop curve steering tasks.
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Karn T, Cinelli ME. The effect of galvanic vestibular stimulation on path trajectory during a path integration task. Q J Exp Psychol (Hove) 2018; 72:1550-1560. [DOI: 10.1177/1747021818798824] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The purpose of this study was to determine the effects of galvanic vestibular stimulation (GVS) on path trajectory and body rotation during a triangle completion task. Participants ( N = 17, female, 18-30 years) completed the triangle completion task in virtual reality using two different size triangles. GVS was delivered at three times each participant’s threshold in either the left or right direction prior to the final leg of the triangle and continued until the participant reached their final position. Whole body kinematics were collected using an NDI Optotrak motion tracking system. Results revealed a significant main effect of GVS on arrival error such that no GVS (NGVS) had significantly smaller arrival errors than when GVS was administered. There was also a significant main effect of GVS on angular error such that NGVS had significantly smaller error than GVSaway and GVStowards. There was no significant difference between GVS trials in path variability during the final leg on route to the final position. These results demonstrate that vestibular perturbation reduced the accuracy of the triangle completion task, affecting path trajectory and body position during a path integration task in the absence of visual cues.
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Affiliation(s)
- Tanya Karn
- Department of Kinesiology and Physical Education, Wilfrid Laurier University, Waterloo, ON, Canada
| | - Michael E Cinelli
- Department of Kinesiology and Physical Education, Wilfrid Laurier University, Waterloo, ON, Canada
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15
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Khoshnam M, Häner DMC, Kuatsjah E, Zhang X, Menon C. Effects of Galvanic Vestibular Stimulation on Upper and Lower Extremities Motor Symptoms in Parkinson's Disease. Front Neurosci 2018; 12:633. [PMID: 30254564 PMCID: PMC6141687 DOI: 10.3389/fnins.2018.00633] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Accepted: 08/23/2018] [Indexed: 11/17/2022] Open
Abstract
As a neurodegenerative movement disorder, Parkinson’s disease (PD) is commonly characterized by motor symptoms such as resting tremor, rigidity, bradykinesia, and balance and postural impairments. While the main cause of PD is still not clear, it is shown that the basal ganglia loop, which has a role in adjusting a planned movement execution through fine motor control, is altered during this disease and contributes toward the manifested motor symptoms. Galvanic vestibular stimulation (GVS) is a non-invasive technique to influence the vestibular system and stimulate the motor system. This study explores how the motor symptoms of upper and lower extremities in PD are instantly affected by vestibular stimulation. In this regard, direct current GVS was applied to 11 individuals with PD on medication while they were performing two sets of experiments: (1) Instrumented Timed Up and Go (iTUG) test and (2) finger tapping task. The performance of participants was recorded with accelerometers and cameras for offline processing of data. Several outcome measures including coefficient of variation of the step duration, gait phase, phase coordination index, tapping score, and the number and duration of manual motor blocks (MMBs) were considered for objective quantifying of performance. Results showed that almost all of considered outcome measures were improved with the application of GVS and that the improvement in the coefficient of variation of the step duration, the tapping score, and the number of MMBs was statistically significant (p-value < 0.05). The results of this study suggest that GVS can be used to alleviate some of the common motor symptoms of PD. Further research is required to fully characterize the effects of GVS and determine its efficacy in the long term.
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Affiliation(s)
- Mahta Khoshnam
- Menrva Research Group, Schools of Mechatronic Systems and Engineering Science, Simon Fraser University, Burnaby, BC, Canada
| | - Daniela M C Häner
- Menrva Research Group, Schools of Mechatronic Systems and Engineering Science, Simon Fraser University, Burnaby, BC, Canada.,ETH Zürich, Zurich, witzerland
| | - Eunice Kuatsjah
- Menrva Research Group, Schools of Mechatronic Systems and Engineering Science, Simon Fraser University, Burnaby, BC, Canada
| | - Xin Zhang
- Menrva Research Group, Schools of Mechatronic Systems and Engineering Science, Simon Fraser University, Burnaby, BC, Canada
| | - Carlo Menon
- Menrva Research Group, Schools of Mechatronic Systems and Engineering Science, Simon Fraser University, Burnaby, BC, Canada
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Abstract
The neural control of balance during locomotion is currently not well understood, even in the light of considerable advances in research on balance during standing. In this paper, we lay out the control problem for this task and present a list of different strategies available to the central nervous system to solve this problem. We discuss the biomechanics of the walking body, using a simplified model that iteratively gains degrees of freedom and complexity. Each addition allows for different control strategies, which we introduce in turn: foot placement shift, ankle strategy, hip strategy, and push-off modulation. The dynamics of the biomechanical system are discussed using the phase space representation, which allows illustrating the mechanical effect of the different control mechanisms. This also enables us to demonstrate the effects of common general stability strategies, such as increasing step width and cadence.
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17
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Tinga AM, Jansen C, van der Smagt MJ, Nijboer TCW, van Erp JBF. Inducing circular vection with tactile stimulation encircling the waist. Acta Psychol (Amst) 2018; 182:32-38. [PMID: 29128511 DOI: 10.1016/j.actpsy.2017.11.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2017] [Revised: 08/22/2017] [Accepted: 11/05/2017] [Indexed: 11/15/2022] Open
Abstract
In general, moving sensory stimuli (visual and auditory) can induce illusory sensations of self-motion (i.e. vection) in the direction opposite of the sensory stimulation. The aim of the current study was to examine whether tactile stimulation encircling the waist could induce circular vection (around the body's yaw axis) and to examine whether this type of stimulation would influence participants' walking trajectory and balance. We assessed the strength and direction of perceived self-motion while vision was blocked and while either receiving tactile stimulation encircling the waist clockwise or counterclockwise or no tactile stimulation. Additionally, we assessed participants' walking trajectory and balance while receiving these different stimulations. Tactile stimulation encircling the waist was found to lead to self-reported circular vection in a subset of participants. In this subset of participants, circular vection was on average experienced in the same direction as the tactile stimulation. Additionally, perceived rotatory self-motion in participants that reported circular vection correlated with balance (i.e., sway velocity and the standard error of the mean in the medio-lateral dimension). The fact that, in this subset of participants, subjective reports of vection correlated with objective outcome measures indicates that tactile stimulation encircling the waist might indeed be able to induced circular vection.
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Affiliation(s)
- Angelica M Tinga
- TNO, Department of Perceptual and Cognitive Systems, Soesterberg, The Netherlands; Utrecht University, Department of Experimental Psychology, Helmholtz Institute, Utrecht, The Netherlands; Tilburg University, Department of Communication and Information Sciences, Tilburg, The Netherlands.
| | - Chris Jansen
- TNO, Department of Perceptual and Cognitive Systems, Soesterberg, The Netherlands
| | - Maarten J van der Smagt
- Utrecht University, Department of Experimental Psychology, Helmholtz Institute, Utrecht, The Netherlands
| | - Tanja C W Nijboer
- Utrecht University, Department of Experimental Psychology, Helmholtz Institute, Utrecht, The Netherlands; Brain Center Rudolf Magnus, and Center of Excellence for Rehabilitation Medicine, University Medical Center Utrecht, and De Hoogstraat Rehabilitation, The Netherlands
| | - Jan B F van Erp
- TNO, Department of Perceptual and Cognitive Systems, Soesterberg, The Netherlands; Twente University, Department of Human Media Interaction, Enschede, The Netherlands
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Lam CK, Staines WR, Tokuno CD, Bent LR. The medium latency muscle response to a vestibular perturbation is increased after depression of the cerebellar vermis. Brain Behav 2017; 7:e00782. [PMID: 29075558 PMCID: PMC5651382 DOI: 10.1002/brb3.782] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/20/2016] [Revised: 06/06/2017] [Accepted: 06/12/2017] [Indexed: 12/20/2022] Open
Abstract
INTRODUCTION Galvanic vestibular stimulation (GVS) is able to evoke distinct responses in the muscles used for balance. These reflexes, termed the short (SL) and medium latency (ML) responses, can be altered by sensory input; decreasing in size when additional sensory cues are available. Although much is known about these responses, the origin and role of the responses are still not fully understood. It has been suggested that the cerebellum, a structure that is involved in postural control and sensory integration, may play a role in the modulation of these reflexes. METHODS The cerebellar vermis was temporarily depressed using continuous theta burst stimulation and SL, ML and overall vestibular electromyographic and force plate shear response amplitudes were compared before and after cerebellar depression. RESULTS There were no changes in force plate shear amplitude and a non-significant increase for the SL muscle response (p = .071), however, we did find significant increases in the ML and overall vestibular muscle response amplitudes after cerebellar depression (p = .026 and p = .016, respectively). No changes were evoked when a SHAM stimulus was used. DISCUSSION These results suggest that the cerebellar vermis plays a role in the modulation of vestibular muscle reflex responses to GVS.
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Characterizing Patients with Unilateral Vestibular Hypofunction Using Kinematic Variability and Local Dynamic Stability during Treadmill Walking. Behav Neurol 2017; 2017:4820428. [PMID: 28785135 PMCID: PMC5530428 DOI: 10.1155/2017/4820428] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Accepted: 04/30/2017] [Indexed: 11/30/2022] Open
Abstract
Here, we aimed to compare the unstable gait caused by unilateral vestibular hypofunction (UVH) with the normal gait. Twelve patients with UVH and twelve age-matched control subjects were enrolled in the study. Thirty-four markers were attached to anatomical positions of each participant, and a three-dimensional (3D) motion analysis system was used to capture marker coordinates as the participants walked on a treadmill. The mean standard deviation of the rotation angles was used to represent gait variability. To explore gait stability, local dynamic stability was calculated from the trunk trajectory. The UVH group had wider step width and greater variability of roll rotation at the hip than the control group (P < 0.05). Also, the UVH group had lower local dynamic stability in the medial-lateral (ML) direction than the control group (P < 0.05). By linear regression analysis, we identified a linear relationship between the short-term Lyapunov exponent and vestibular functional asymmetry. The result implies that UVH-induced asymmetry can increase posture variability and gait instability. This study demonstrates the potential for using kinematic parameters to quantitatively evaluate the severity of vestibular functional asymmetry. Further studies will be needed to explore the clinical effectiveness of such approaches.
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Reimann H, Fettrow TD, Thompson ED, Agada P, McFadyen BJ, Jeka JJ. Complementary mechanisms for upright balance during walking. PLoS One 2017; 12:e0172215. [PMID: 28234936 PMCID: PMC5325219 DOI: 10.1371/journal.pone.0172215] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Accepted: 02/01/2017] [Indexed: 12/16/2022] Open
Abstract
Lateral balance is a critical factor in keeping the human body upright during walking. Two important mechanisms for balance control are the stepping strategy, in which the foot placement is changed in the direction of a sensed fall to modulate how the gravitational force acts on the body, and the lateral ankle strategy, in which the body mass is actively accelerated by an ankle torque. Currently, there is minimal evidence about how these two strategies complement one another to achieve upright balance during locomotion. We use Galvanic vestibular stimulation (GVS) to induce the sensation of a fall at heel-off during gait initiation. We found that young healthy adults respond to the illusory fall using both the lateral ankle strategy and the stepping strategy. The stance foot center of pressure (CoP) is shifted in the direction of the perceived fall by ≈2.5 mm, starting ≈247 ms after stimulus onset. The foot placement of the following step is shifted by ≈15 mm in the same direction. The temporal delay between these two mechanisms suggests that they independently contribute to upright balance during locomotion, potentially in a serially coordinated manner. Modeling results indicate that without the lateral ankle strategy, a much larger step width is required to maintain upright balance, suggesting that the small but early CoP shift induced by the lateral ankle strategy is critical for upright stability during locomotion. The relative importance of each mechanism and how neurological disorders may affect their implementation remain an open question.
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Affiliation(s)
- Hendrik Reimann
- Department of Kinesiology, Temple University, Philadelphia, PA, United States of America
- * E-mail:
| | - Tyler D. Fettrow
- Department of Kinesiology, Temple University, Philadelphia, PA, United States of America
| | - Elizabeth D. Thompson
- Department of Kinesiology, Temple University, Philadelphia, PA, United States of America
- Department of Physical Therapy, Temple University, Philadelphia, PA, United States of America
| | - Peter Agada
- Department of Kinesiology, Temple University, Philadelphia, PA, United States of America
| | - Bradford J. McFadyen
- Centre for Interdisciplinary Research in Rehabilitation and Social Integration, Université Laval, Québec, Canada
- Department of Rehabilitation, Université Laval, Québec, Canada
| | - John J. Jeka
- Department of Kinesiology, Temple University, Philadelphia, PA, United States of America
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Toth AJ, Harris LR, Zettel J, Bent LR. Vision can recalibrate the vestibular reafference signal used to re-establish postural equilibrium following a platform perturbation. Exp Brain Res 2016; 235:407-414. [PMID: 27752729 DOI: 10.1007/s00221-016-4801-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Accepted: 10/11/2016] [Indexed: 11/29/2022]
Abstract
Visuo-vestibular recalibration, in which visual information is used to alter the interpretation of vestibular signals, has been shown to influence both oculomotor control and navigation. Here we investigate whether vision can recalibrate the vestibular feedback used during the re-establishment of equilibrium following a perturbation. The perturbation recovery responses of nine participants were examined following exposure to a period of 11 s of galvanic vestibular stimulation (GVS). During GVS in VISION trials, occlusion spectacles provided 4 s of visual information that enabled participants to correct for the GVS-induced tilt and associate this asymmetric vestibular signal with a visually provided 'upright'. NoVISION trials had no such visual experience. Participants used the visual information to assist in realigning their posture compared to when visual information was not provided (p < 0.01). The initial recovery response to a platform perturbation was not impacted by whether vision had been provided during the preceding GVS, as determined by peak centre of mass and pressure deviations (p = 0.09). However, after using vision to reinterpret the vestibular signal during GVS, final centre of mass and pressure equilibrium positions were significantly shifted compared to trials in which vision was not available (p < 0.01). These findings support previous work identifying a prominent role of vestibular input for re-establishing postural equilibrium following a perturbation. Our work is the first to highlight the capacity for visual feedback to recalibrate the vertical interpretation of vestibular reafference for re-establishing equilibrium following a perturbation. This demonstrates the rapid adaptability of the vestibular reafference signal for postural control.
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Affiliation(s)
- Adam J Toth
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON, N1G 2W1, Canada
| | - Laurence R Harris
- Centre for Vision Research, Department of Psychology, York University, Toronto, ON, M3J 1P3, Canada
| | - John Zettel
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON, N1G 2W1, Canada
| | - Leah R Bent
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON, N1G 2W1, Canada.
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Lam CK, Tokuno CD, Staines WR, Bent LR. The direction of the postural response to a vestibular perturbation is mediated by the cerebellar vermis. Exp Brain Res 2016; 234:3689-3697. [DOI: 10.1007/s00221-016-4766-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Accepted: 08/27/2016] [Indexed: 12/19/2022]
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Gálvez-García G, Hay M, Gabaude C. Alleviating simulator sickness with galvanic cutaneous stimulation. HUMAN FACTORS 2015; 57:649-657. [PMID: 25977323 DOI: 10.1177/0018720814554948] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2014] [Accepted: 09/16/2014] [Indexed: 06/04/2023]
Abstract
OBJECTIVE In a driving simulation, we investigated the efficacy of galvanic cutaneous stimulation (GCS) provided during curves or intermittently during the whole circuit to mitigate simulator syndrome (SS). BACKGROUND The literature on how GCS decreases SS, although scarce, has demonstrated the effectiveness of this technique. Stimulation with this and similar techniques has usually been provided in curves or continuously during the whole circuit but never intermittently. This stimulation method could generate a continued activation of processes related to GCS mitigating SS. METHOD Fifteen drivers (8 men; mean age = 25.5 years) participated in this experiment. We compared the total scores of the Simulator Sickness Questionnaire (SSQ) across three stimulation conditions: (a) curve GCS condition, whereby GCS was provided in curves; (b) intermittent GCS condition, whereby GCS was provided intermittently during the whole circuit; and (c) no-stimulation condition, whereby no stimulation was provided (baseline condition). RESULTS The experimental outcomes revealed that GCS decreased SS in both the curve and intermittent stimulation conditions. CONCLUSION We provide evidence that GCS is an effective countermeasure to decrease SS. It could be applied indifferently in curves or intermittently during the whole circuit. APPLICATION For future interventions, we recommend the use of GCS to mitigate SS with similar intermittent stimulation programs. These programs have a crucial advantage as they are easily integrated into the simulator setup without the necessity of generating a complicated experimental design to stimulate during the curves.
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Affiliation(s)
- Germán Gálvez-García
- Université de Lyon IFSTTAR-LESCOT F-69675, Bron, FranceUniversity of Padova, Padova, Italy
| | - Marion Hay
- Université de Lyon IFSTTAR-LESCOT F-69675, Bron, FranceINSERM U1075 COMETE, Caen, France
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Paquet N, Taillon-Hobson A, Lajoie Y. Effect of ankle weight on blind navigation. Percept Mot Skills 2015; 120:502-18. [PMID: 25747457 DOI: 10.2466/25.pms.120v10x0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
This study tested the hypotheses that loading the ankle with a 2.3 kg weight would modify deviation (unilateral loading) and distance (unilateral and bilateral loading) during three blind navigation tasks. Ankle loading increased the distance traveled while navigating toward a previously seen target at an 8 m distance and reduced the undetected fore-aft displacement while stepping in place for 100 steps. Unilateral ankle loading had no effect on deviation during these tasks, nor in walking back and forth on an imaginary straight line. The results suggest that somatosensory cues associated with ankle loading and the increased effort to walk and step interacted with motor and cognitive functions involved in blind navigation and influenced the control of anterior-posterior body displacement.
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Affiliation(s)
- Nicole Paquet
- 1 School of Rehabilitation Sciences, University of Ottawa
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Trojaniello D, Cereatti A, Ravaschio A, Bandettini M, Della Croce U. Assessment of gait direction changes during straight-ahead walking in healthy elderly and Huntington disease patients using a shank worn MIMU. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2015; 2014:2508-11. [PMID: 25570500 DOI: 10.1109/embc.2014.6944132] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The aim of this study was to propose and comparatively evaluate four methods for assessing stride-by-stride changes of direction of progression, during straight walking using measurements of a magnetic and inertial unit placed above the malleolus. The four methods were evaluated by comparing their estimate of the gait changes of direction of progression with that obtained from an instrumented gait mat used as a gold standard. The methods were applied to the data obtained from the gait of both healthy subjects and patients with Huntington Disease, the latter characterized by a jerky swing phase. The results showed that the errors associated to the best estimates of the gait direction changes were about 10% of its range of variability for the healthy subjects and increased to about 30% for the patients, both walking at comfortable speed when the range of variability is the largest. Additional testing on gait at various radius of curvature should be carried out to fully validate the MIMU-based estimates.
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Comparison of postural responses to galvanic vestibular stimulation between pilots and the general populace. BIOMED RESEARCH INTERNATIONAL 2015; 2015:567690. [PMID: 25632395 PMCID: PMC4302968 DOI: 10.1155/2015/567690] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/07/2014] [Revised: 09/09/2014] [Accepted: 09/17/2014] [Indexed: 11/17/2022]
Abstract
Galvanic vestibular stimulation (GVS) can be used to study the body's response to vestibular stimuli. This study aimed to investigate whether postural responses to GVS were different between pilots and the general populace. Bilateral bipolar GVS was applied with a constant-current profile to 12 pilots and 12 control subjects via two electrodes placed over the mastoid processes. Both GVS threshold and the center of pressure's trajectory (COP's trajectory) were measured. Position variability of COP during spontaneous body sway and peak displacement of COP during GVS-induced body sway were calculated in the medial-lateral direction. Spontaneous body sway was slight for all subjects, and there was no significant difference in the value of COP position variability between the pilots and controls. Both the GVS threshold and magnitude of GVS-induced body deviation were similar for different GVS polarities. GVS thresholds were similar between the two groups, but the magnitude of GVS-induced body deviation in the controls was significantly larger than that in the pilots. The pilots showed less GVS-induced body deviation, meaning that pilots may have a stronger ability to suppress vestibular illusions.
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Kim SC, Kim JY, Lee HN, Lee HH, Kwon JH, Kim NB, Kim MJ, Hwang JH, Han GC. A quantitative analysis of gait patterns in vestibular neuritis patients using gyroscope sensor and a continuous walking protocol. J Neuroeng Rehabil 2014; 11:58. [PMID: 24725764 PMCID: PMC3991869 DOI: 10.1186/1743-0003-11-58] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2013] [Accepted: 04/07/2014] [Indexed: 11/27/2022] Open
Abstract
Background Locomotion involves an integration of vision, proprioception, and vestibular information. The parieto-insular vestibular cortex is known to affect the supra-spinal rhythm generators, and the vestibular system regulates anti-gravity muscle tone of the lower leg in the same side to maintain an upright posture through the extra-pyramidal track. To demonstrate the relationship between locomotion and vestibular function, we evaluated the differences in gait patterns between vestibular neuritis (VN) patients and normal subjects using a gyroscope sensor and long-way walking protocol. Methods Gyroscope sensors were attached to both shanks of healthy controls (n=10) and age-matched VN patients (n = 10). We then asked the participants to walk 88.8 m along a corridor. Through the summation of gait cycle data, we measured gait frequency (Hz), normalized angular velocity (NAV) of each axis for legs, maximum and minimum NAV, up-slope and down-slope of NAV in swing phase, stride-swing-stance time (s), and stance to stride ratio (%). Results The most dominant walking frequency in the VN group was not different compared to normal control. The NAVs of z-axis (pitch motion) were significantly larger than the others (x-, y-axis) and the values in VN patients tended to decrease in both legs and the difference of NAV between both group was significant in the ipsi-lesion side in the VN group only (p=0.03). Additionally, the gait velocity of these individuals was decreased relatively to controls (1.11 ± 0.120 and 0.84 ± 0.061 m/s in control and VN group respectively, p<0.01), which seems to be related to the significantly increased stance and stride time of the ipsi-lesion side. Moreover, in the VN group, the maximum NAV of the lesion side was less, and the minimum one was higher than control group. Furthermore, the down-slope and up-slope of NAV decreased on the impaired side. Conclusion The walking pattern of VN patients was highly phase-dependent, and NAV of pitch motion was significantly decreased in the ipsi-lesion side. The change of gait rhythm, stance and stride time, and maximum/minimum NAV of the ipsi-lesion side were characteristics of individuals with VN.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Gyu Cheol Han
- Department of Otolaryngology-Head and Neck Surgery, Gachon University of Medicine and Science, Graduate School of Medicine, Incheon, South Korea.
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Deshpande N, Zhang F. Trunk, Head, and Step Characteristics During Normal and Narrow-Based Walking Under Deteriorated Sensory Conditions. J Mot Behav 2014; 46:125-32. [DOI: 10.1080/00222895.2013.877416] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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29
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Maaswinkel E, Veeger HEJ, Dieen JH. Interactions of touch feedback with muscle vibration and galvanic vestibular stimulation in the control of trunk posture. Gait Posture 2014; 39:745-9. [PMID: 24192277 DOI: 10.1016/j.gaitpost.2013.10.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/19/2013] [Revised: 09/25/2013] [Accepted: 10/12/2013] [Indexed: 02/02/2023]
Abstract
This study investigated the effect of touch on trunk sway in a seated position. Two touch conditions were included: touching an object with the index finger of the right hand (hand-touch) and maintaining contact with an object at the level of the spine of T10 on the mid back (back-touch). In both touch conditions, the exerted force stayed below 2N. Furthermore, the interaction of touch with paraspinal muscle vibration and galvanic vestibular stimulation (GVS) was studied. Thirteen healthy subjects with no history of low-back pain participated in this study. Subjects sat on a stool and trunk sway was measured with a motion capture system tracking a cluster marker on the trunk. Subjects performed a total of 12 trials of 60-s duration in a randomized order, combining the experimental conditions of no-touch, hand-touch or back-touch with no sensory perturbation, paraspinal muscle vibration or GVS. The results showed that touch through hand or back decreased trunk sway and decreased the effects of muscle vibration and GVS. GVS led to a large increase in sway whereas the effect of muscle vibration was only observed as an increase of drift and not of sway. In the current experimental set-up, the stabilizing effect of touch was strong enough to mask any effects of perturbations of vestibular and paraspinal muscle spindle afference. In conclusion, tactile information, whenever available, seems to play a dominant role in seated postural sway and therefore has important implications for studying trunk control.
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Affiliation(s)
- E Maaswinkel
- Research Institute MOVE, Institute for Fundamental and Clinical Human Movement Sciences, Faculty of Human Movement Sciences, 'Vrije Universiteit Amsterdam', Van der Boechorststraat 9, NL-1081 BT Amsterdam, The Netherlands
| | - H E J Veeger
- Research Institute MOVE, Institute for Fundamental and Clinical Human Movement Sciences, Faculty of Human Movement Sciences, 'Vrije Universiteit Amsterdam', Van der Boechorststraat 9, NL-1081 BT Amsterdam, The Netherlands
| | - J Hv Dieen
- Research Institute MOVE, Institute for Fundamental and Clinical Human Movement Sciences, Faculty of Human Movement Sciences, 'Vrije Universiteit Amsterdam', Van der Boechorststraat 9, NL-1081 BT Amsterdam, The Netherlands.
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30
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Kim DJ, Yogendrakumar V, Chiang J, Ty E, Wang ZJ, McKeown MJ. Noisy galvanic vestibular stimulation modulates the amplitude of EEG synchrony patterns. PLoS One 2013; 8:e69055. [PMID: 23874865 PMCID: PMC3715484 DOI: 10.1371/journal.pone.0069055] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2013] [Accepted: 06/02/2013] [Indexed: 11/18/2022] Open
Abstract
Noisy galvanic vestibular stimulation has been associated with numerous cognitive and behavioural effects, such as enhancement of visual memory in healthy individuals, improvement of visual deficits in stroke patients, as well as possibly improvement of motor function in Parkinson’s disease; yet, the mechanism of action is unclear. Since Parkinson’s and other neuropsychiatric diseases are characterized by maladaptive dynamics of brain rhythms, we investigated whether noisy galvanic vestibular stimulation was associated with measurable changes in EEG oscillatory rhythms within theta (4–7.5 Hz), low alpha (8–10 Hz), high alpha (10.5–12 Hz), beta (13–30 Hz) and gamma (31–50 Hz) bands. We recorded the EEG while simultaneously delivering noisy bilateral, bipolar stimulation at varying intensities of imperceptible currents – at 10, 26, 42, 58, 74 and 90% of sensory threshold – to ten neurologically healthy subjects. Using standard spectral analysis, we investigated the transient aftereffects of noisy stimulation on rhythms. Subsequently, using robust artifact rejection techniques and the Least Absolute Shrinkage Selection Operator regression and cross-validation, we assessed the combinations of channels and power spectral features within each EEG frequency band that were linearly related with stimulus intensity. We show that noisy galvanic vestibular stimulation predominantly leads to a mild suppression of gamma power in lateral regions immediately after stimulation, followed by delayed increase in beta and gamma power in frontal regions approximately 20–25 s after stimulation ceased. Ongoing changes in the power of each oscillatory band throughout frontal, central/parietal, occipital and bilateral electrodes predicted the intensity of galvanic vestibular stimulation in a stimulus-dependent manner, demonstrating linear effects of stimulation on brain rhythms. We propose that modulation of neural oscillations is a potential mechanism for the previously-described cognitive and motor effects of vestibular stimulation, and noisy galvanic vestibular stimulation may provide an additional non-invasive means for neuromodulation of functional brain networks.
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Affiliation(s)
- Diana J. Kim
- Neuroscience, University of British Columbia, Vancouver, Canada
| | | | - Joyce Chiang
- Department of Electrical and Computer Engineering, University of British Columbia, Vancouver, Canada
| | - Edna Ty
- Pacific Parkinson’s Research Centre, Vancouver, Canada
| | - Z. Jane Wang
- Department of Electrical and Computer Engineering, University of British Columbia, Vancouver, Canada
| | - Martin J. McKeown
- Pacific Parkinson’s Research Centre, Vancouver, Canada
- Department of Electrical and Computer Engineering, University of British Columbia, Vancouver, Canada
- Department of Medicine (Neurology), University of British Columbia, Vancouver, Canada
- Brain Research Centre, University of British Columbia, Vancouver, Canada
- * E-mail:
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31
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Blouin JS, Dakin CJ, van den Doel K, Chua R, McFadyen BJ, Inglis JT. Extracting phase-dependent human vestibular reflexes during locomotion using both time and frequency correlation approaches. J Appl Physiol (1985) 2011; 111:1484-90. [DOI: 10.1152/japplphysiol.00621.2011] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Daily activities, such as walking, may require dynamic modulation of vestibular input onto motoneurons. This dynamic modulation is difficult to identify in humans due to limitations in the delivery and analysis of current vestibular probes, such as galvanic vestibular stimulation. Stochastic vestibular stimulation, however, provides an alternative method to extract human vestibular reflexes. Here, we used time-dependent coherence and time-dependent cross-correlation, coupled with stochastic vestibular stimulation, to investigate the phase dependency of human vestibular reflexes during locomotion. We found that phase-dependent activity from the medial gastrocnemius muscles is correlated with the vestibular signals over the 2- to 20-Hz bandwidth during the stance phase of locomotion. Vestibular-gastrocnemius coherence and time-dependent cross-correlations reached maximums at 21 ± 4 and 23 ± 8% of the step cycle following heel contact and before the period of maximal electromyographic activity (38 ± 5%). These results demonstrate 1) the effectiveness of these techniques in extracting the phase-dependent modulation of vestibulomuscular coupling during a cyclic task; 2) that vestibulomuscular coupling is phasically modulated during locomotion; and 3) that the period of strongest vestibulomuscular coupling does not correspond to the period of maximal electromyographic activity in the gastrocnemius. Therefore, we have shown that stochastic vestibular stimulation, coupled with time-frequency decomposition, provides an effective tool to assess the contribution of vestibular ex-afference to the muscular control during locomotion.
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Affiliation(s)
- Jean-Sébastien Blouin
- School of Kinesiology,
- Brain Research Center,
- Institute for Computing, Information and Cognitive Systems, and
| | | | | | | | - Bradford J. McFadyen
- Centre for Interdisciplinary Research in Rehabilitation and Social integration, and
- Department of Rehabilitation, Laval University, Québec, Canada
| | - John Timothy Inglis
- School of Kinesiology,
- Brain Research Center,
- International Collaboration for Repair Discoveries, University of British Columbia, Vancouver, British Columbia
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Yin M, Ishikawa K, Omi E, Saito T, Itasaka Y, Angunsuri N. Small vestibular schwannomas can cause gait instability. Gait Posture 2011; 34:25-8. [PMID: 21482113 DOI: 10.1016/j.gaitpost.2011.02.026] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/25/2010] [Revised: 12/22/2010] [Accepted: 02/28/2011] [Indexed: 02/02/2023]
Abstract
PURPOSE To confirm whether detailed gait analysis can detect gait instability in patients with small vestibular schwannoma (VS) with an apparently normal gait. METHODS Twenty-two patients (7 males, 15 females; 40-64 years old) with small VS and nine healthy age- and weight-matched controls were enrolled. Small VS was defined as the longest diameter less than 20mm from the porus acusticus internus on MRI with no brainstem compression. Each subject was asked to walk straight for a distance of 8m with tactile sensors attached to both feet, and repeat two trials with eyes open and closed. Gait variables of stance, swing, double support, stability, and average length of the trajectories of the center of force (TCOF) during stance were recorded and analyzed. RESULTS No significant differences in the stability of the TCOF were found during gaits with eyes open and closed between the two groups. No obvious changes in gait variables were recognized with eyes open between the two groups. However, under gait with eyes closed, the values of the coefficient of variation (CV) of the gait phase were significantly greater in stance and swing in the VS group than in the normal group. In addition, patients with canal paresis (CP) showed greater CV values in gait phase related parameters than those who without CP during gait with eyes closed. CONCLUSIONS Patients with small VS may have an apparently normal gait, but their vestibular deficit could be detected by proper use of gait analysis, especially with visual deprivation.
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Affiliation(s)
- M Yin
- Division of Otolaryngology, Head and Neck Surgery, Department of Sensory Medicine, Akita University School of Medicine, Hondo 1-1-1, Akita 010-8543, Japan.
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33
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van Schooten KS, Sloot LH, Bruijn SM, Kingma H, Meijer OG, Pijnappels M, van Dieën JH. Sensitivity of trunk variability and stability measures to balance impairments induced by galvanic vestibular stimulation during gait. Gait Posture 2011; 33:656-60. [PMID: 21435878 DOI: 10.1016/j.gaitpost.2011.02.017] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/11/2010] [Revised: 02/03/2011] [Accepted: 02/22/2011] [Indexed: 02/02/2023]
Abstract
For targeted prevention of falls, it is necessary to identify individuals with balance impairments. To test the sensitivity of measures of variability, local stability and orbital stability of trunk kinematics to balance impairments during gait, we used galvanic vestibular stimulation (GVS) to impair balance in 12 young adults while walking on a treadmill at different speeds. Inertial sensors were used to measure trunk accelerations, from which variability in the medio-lateral direction and local and orbital stability were calculated. The short-term Lyapunov exponent and variability reflected the destabilizing effect of GVS, while the long-term Lyapunov exponent and Floquet multipliers suggested increased stability. Therefore, we concluded that only short-term Lyapunov exponents and variability can be used to asses stability of gait. In addition, to investigate the feasibility of using these measures in screening for fall risk, the presence or absence of GVS was predicted with variability and the short-term Lyapunov exponent. Predictions were good at all walking speeds, but best at preferred walking speed, with a correct classification in 83.3% of the cases.
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Affiliation(s)
- Kimberley S van Schooten
- Research Institute MOVE, Faculty of Human Movement Sciences, VU University Amsterdam, Amsterdam, The Netherlands
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34
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St George RJ, Day BL, Fitzpatrick RC. Adaptation of vestibular signals for self-motion perception. J Physiol 2011; 589:843-53. [PMID: 20937715 PMCID: PMC3060364 DOI: 10.1113/jphysiol.2010.197053] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2010] [Accepted: 10/10/2010] [Indexed: 11/08/2022] Open
Abstract
A fundamental concern of the brain is to establish the spatial relationship between self and the world to allow purposeful action. Response adaptation to unvarying sensory stimuli is a common feature of neural processing, both peripherally and centrally. For the semicircular canals, peripheral adaptation of the canal-cupula system to constant angular-velocity stimuli dominates the picture and masks central adaptation. Here we ask whether galvanic vestibular stimulation circumvents peripheral adaptation and, if so, does it reveal central adaptive processes. Transmastoidal bipolar galvanic stimulation and platform rotation (20 deg s−1) were applied separately and held constant for 2 min while perceived rotation was measured by verbal report. During real rotation, the perception of turn decayed from the onset of constant velocity with a mean time constant of 15.8 s. During galvanic-evoked virtual rotation, the perception of rotation initially rose but then declined towards zero over a period of ∼100 s. For both stimuli, oppositely directed perceptions of similar amplitude were reported when stimulation ceased indicating signal adaptation at some level. From these data the time constants of three independent processes were estimated: (i) the peripheral canal-cupula adaptation with time constant 7.3 s, (ii) the central ‘velocity-storage' process that extends the afferent signal with time constant 7.7 s, and (iii) a long-term adaptation with time constant 75.9 s. The first two agree with previous data based on constant-velocity stimuli. The third component decayed with the profile of a real constant angular acceleration stimulus, showing that the galvanic stimulus signal bypasses the peripheral transformation so that the brainstem sees the galvanic signal as angular acceleration. An adaptive process involving both peripheral and central processes is indicated. Signals evoked by most natural movements will decay peripherally before adaptation can exert an appreciable effect, making a specific vestibular behavioural role unlikely. This adaptation appears to be a general property of the internal coding of self-motion that receives information from multiple sensory sources and filters out the unvarying components regardless of their origin. In this instance of a pure vestibular sensation, it defines the afferent signal that represents the stationary or zero-rotation state.
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Affiliation(s)
- Rebecca J St George
- Neuroscience Research Australia, Barker Street, Randwick, NSW 2031, Australia.
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35
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Sloot LH, van Schooten KS, Bruijn SM, Kingma H, Pijnappels M, van Dieën JH. Sensitivity of local dynamic stability of over-ground walking to balance impairment due to galvanic vestibular stimulation. Ann Biomed Eng 2011; 39:1563-9. [PMID: 21222163 PMCID: PMC3071943 DOI: 10.1007/s10439-010-0240-y] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2010] [Accepted: 12/23/2010] [Indexed: 11/26/2022]
Abstract
Impaired balance control during gait can be detected by local dynamic stability measures. For clinical applications, the use of a treadmill may be limiting. Therefore, the aim of this study was to test sensitivity of these stability measures collected during short episodes of over-ground walking by comparing normal to impaired balance control. Galvanic vestibular stimulation (GVS) was used to impair balance control in 12 healthy adults, while walking up and down a 10 m hallway. Trunk kinematics, collected by an inertial sensor, were divided into episodes of one stroll along the hallway. Local dynamic stability was quantified using short-term Lyapunov exponents (λs), and subjected to a bootstrap analysis to determine the effects of number of episodes analysed on precision and sensitivity of the measure. λs increased from 0.50 ± 0.06 to 0.56 ± 0.08 (p = 0.0045) when walking with GVS. With increasing number of episodes, coefficients of variation decreased from 10 ± 1.3% to 5 ± 0.7% and the number of p values >0.05 from 42 to 3.5%, indicating that both precision of estimates of λs and sensitivity to the effect of GVS increased. λs calculated over multiple episodes of over-ground walking appears to be a suitable measure to calculate local dynamic stability on group level.
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Affiliation(s)
- Lizeth H. Sloot
- Research Institute MOVE, Faculty of Human Movement Sciences, VU University Amsterdam, Van der Boechorststraat 9, 1081 BT Amsterdam, The Netherlands
| | - Kimberley S. van Schooten
- Research Institute MOVE, Faculty of Human Movement Sciences, VU University Amsterdam, Van der Boechorststraat 9, 1081 BT Amsterdam, The Netherlands
| | - Sjoerd M. Bruijn
- Research Institute MOVE, Faculty of Human Movement Sciences, VU University Amsterdam, Van der Boechorststraat 9, 1081 BT Amsterdam, The Netherlands
| | - Herman Kingma
- Department of Biomedical Engineering, University Hospital Maastricht, Maastricht, The Netherlands
| | - Mirjam Pijnappels
- Research Institute MOVE, Faculty of Human Movement Sciences, VU University Amsterdam, Van der Boechorststraat 9, 1081 BT Amsterdam, The Netherlands
| | - Jaap H. van Dieën
- Research Institute MOVE, Faculty of Human Movement Sciences, VU University Amsterdam, Van der Boechorststraat 9, 1081 BT Amsterdam, The Netherlands
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36
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Wang Y, Kenyon RV, Keshner EA. Identifying the control of physically and perceptually evoked sway responses with coincident visual scene velocities and tilt of the base of support. Exp Brain Res 2009; 201:663-72. [DOI: 10.1007/s00221-009-2082-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2009] [Accepted: 11/02/2009] [Indexed: 10/20/2022]
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37
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Liechti M, Müller R, Lam T, Curt A. Vestibulospinal responses in motor incomplete spinal cord injury. Clin Neurophysiol 2008; 119:2804-12. [PMID: 18842452 DOI: 10.1016/j.clinph.2008.05.033] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2006] [Revised: 05/13/2008] [Accepted: 05/16/2008] [Indexed: 11/18/2022]
Abstract
OBJECTIVE Postural instability limits ambulatory capacity in patients with spinal cord injury (SCI). Galvanic vestibular stimulation (GVS) was used to investigate the integrity of vestibulospinal pathways and related changes in postural responses in SCI. METHODS Binaural bipolar galvanic stimuli of 400 ms duration and 3 mA intensity were applied in 8 motor incomplete SCI and 8 control subjects who stood facing towards the left. EMG responses were recorded from the right soleus muscle and the trajectory of the centre of pressure (CoP) was measured with a force plate. RESULTS There was no difference in excitability and amplitude of the responses between the groups. However, the latency and duration of the medium latency EMG response and all CoP responses were significantly longer in the SCI group. Additionally, postural stability was reduced in the SCI group, as shown by a greater tendency to fall due to GVS. CONCLUSIONS Despite early EMG responses proving the basic connectivity of the direct vestibulospinal pathways, the delayed GVS responses suggest a vestibulospinal deficit in the SCI subjects. SIGNIFICANCE GVS can be applied in incomplete SCI to supplement the neurological examination by revealing changes in vestibulospinal responses and impairment of postural stability.
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Affiliation(s)
- M Liechti
- Balgrist University Hospital, Spinal Cord Injury Center, Forchstrasse 340, 8008 Zurich, Switzerland
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Reed-Jones RJ, Vallis LA, Reed-Jones JG, Trick LM. The relationship between postural stability and virtual environment adaptation. Neurosci Lett 2008; 435:204-9. [PMID: 18359162 DOI: 10.1016/j.neulet.2008.02.047] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2007] [Revised: 02/12/2008] [Accepted: 02/18/2008] [Indexed: 11/27/2022]
Abstract
Currently little is known about how adaptive responses to virtual environments are different between individuals who experience sickness related symptoms and those who do not. It is believed that sensory interactions between visually perceived self-motion and static inertial cues from vestibular and/or proprioceptive sensory systems contribute to the development of adaptation symptoms. The aim of this study was to evaluate the relationship between adaptation symptoms and postural stability in a virtual environment (VE) driving simulator. In addition, the role of sensory interaction was assessed using direct electrical stimulation techniques of the vestibular and cutaneous sensory systems. Posture performance was measured using centre of pressure measures of single leg stance tests during eyes open and eyes closed conditions. Correlation analysis of postural measures and symptom scores were conducted, as well as analysis of variance of posture performance between SICK and WELL individuals. Results indicate that posture stability is negatively correlated to symptom reporting. WELL individuals displayed the greatest decrease in postural stability during eyes open single leg stance following VE simulation. Application of a secondary sensory stimulation (vestibular or cutaneous) resulted in increased visual dependency for postural control following simulation. Combined, these results suggest that sensory interactions drive postural changes that are observed following VE simulation and are related to how visual information is used to control posture.
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Affiliation(s)
- Rebecca J Reed-Jones
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada N1G 2W1
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Schneider E, Jahn K, Dieterich M, Brandt T, Strupp M. Gait deviations induced by visual stimulation in roll. Exp Brain Res 2007; 185:21-6. [PMID: 17909767 DOI: 10.1007/s00221-007-1134-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2007] [Accepted: 09/04/2007] [Indexed: 10/22/2022]
Abstract
Locomotion control uses proprioceptive, visual, and vestibular signals. The vestibular contribution has been analyzed previously with galvanic vestibular stimulation (GVS), which constitutes mainly a virtual head-fixed rotation in the roll plane that causes polarity-specific deviations of gait. In this study we examined whether a visual disturbance has similar effects on gait when it acts in the same direction as GVS, i.e., when roll vection is induced by head-fixed visual roll motion stimulation. Random dot patterns were constantly rotated in roll at +/-15 degrees /s on a computer-driven binocular head-mounted display that was worn by eight healthy participants. Their gait trajectories were tracked while they walked a distance of 6 m. A stimulation effect was observed only for the first three to four steps, but not for the whole walking distance. These results are similar to the results of previous GVS studies, suggesting that in terms of the direction of action visual motion stimulations in the roll plane are similar to GVS. Both kinds of stimulation cause only initial balance responses in the roll plane but do not contribute to the steering of gait in the yaw plane.
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Affiliation(s)
- Erich Schneider
- Department of Neurology, University Hospital of Munich - Grosshadern Ludwig-Maximilians University, Marchioninistr. 23, 81377, Munich, Germany.
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40
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Lenggenhager B, Lopez C, Blanke O. Influence of galvanic vestibular stimulation on egocentric and object-based mental transformations. Exp Brain Res 2007; 184:211-21. [PMID: 17717649 DOI: 10.1007/s00221-007-1095-9] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2006] [Accepted: 08/01/2007] [Indexed: 10/22/2022]
Abstract
The vestibular system analyses angular and linear accelerations of the head that are important information for perceiving the location of one's own body in space. Vestibular stimulation and in particular galvanic vestibular stimulation (GVS) that allow a systematic modification of vestibular signals has so far mainly been used to investigate vestibular influence on sensori-motor integration in eye movements and postural control. Comparatively, only a few behavioural and imaging studies have investigated how cognition of space and body may depend on vestibular processing. This study was designed to differentiate the influence of left versus right anodal GVS compared to sham stimulation on object-based versus egocentric mental transformations. While GVS was applied, subjects made left-right judgments about pictures of a plant or a human body presented at different orientations in the roll plane. All subjects reported illusory sensations of body self-motion and/or visual field motion during GVS. Response times in the mental transformation task were increased during right but not left anodal GVS for the more difficult stimuli and the larger angles of rotation. Post-hoc analyses suggested that the interfering effect of right anodal GVS was only present in subjects who reported having imagined turning themselves to solve the mental transformation task (egocentric transformation) as compared to those subjects having imagined turning the picture in space (object-based mental transformation). We suggest that this effect relies on shared functional and cortical mechanisms in the posterior parietal cortex associated with both right anodal GVS and mental imagery.
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Affiliation(s)
- Bigna Lenggenhager
- Laboratory of Cognitive Neuroscience, Brain Mind Institute, Ecole Polytechnique Fédérale de Lausanne (EPFL), Station 15, 1015, Lausanne, Switzerland
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41
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Reed-Jones RJ, Vallis LA. Proprioceptive deficits of the lower limb following anterior cruciate ligament deficiency affect whole body steering control. Exp Brain Res 2007; 182:249-60. [PMID: 17704908 DOI: 10.1007/s00221-007-1037-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2007] [Accepted: 06/15/2007] [Indexed: 10/22/2022]
Abstract
The role of lower limb proprioception in the steering control of locomotion is still unclear. The purpose of the current study was to determine whether steering control is altered in individuals with reduced lower limb proprioception. Anterior cruciate ligament deficiency (ACLD) results in a decrease in proprioceptive information from the injured knee joint (Barrack et al. 1989). Therefore the whole body kinematics were recorded for eight unilateral ACLD individuals and eight CONTROL individuals during the descent of a 20 degrees incline ramp followed by either a redirection using a side or cross cutting maneuver or a continuation straight ahead. Onset of head and trunk yaw, mediolateral displacement of a weighted center of mass (COM(HT)) and mediolateral displacement of the swing foot were analyzed to evaluate differences in the steering control. Timing analyses revealed that ACLD individuals delayed the reorientation of body segments compared to CONTROL individuals. In addition, ACLD did not use a typical steering synergy where the head leads whole body reorientation; rather ACLD individuals reoriented the head, trunk and COM(HT) in the new direction at the same time. These results suggest that when lower limb proprioceptive information is reduced, the central nervous system (CNS) may delay whole body reorientation to the new travel direction, perhaps in order to integrate existing sensory information (vision, vestibular and proprioception) with the reduced information from the injured knee joint. This control strategy is maintained when visual information is present or reduced in a low light environment. Additionally, the CNS may move the head and trunk segments as, effectively, one segment to decrease the number of degrees of freedom that must be controlled and increase whole body stability during the turning task.
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Affiliation(s)
- Rebecca J Reed-Jones
- Department of Human Health and Nutritional Sciences, College of Biological Science, University of Guelph, Animal Science/Nutrition Building, Guelph, ON, Canada N1G 2W1
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Bent LR, Bolton PS, Macefield VG. Vestibular inputs do not influence the fusimotor system in relaxed muscles of the human leg. Exp Brain Res 2007; 180:97-103. [PMID: 17221220 DOI: 10.1007/s00221-006-0836-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2006] [Accepted: 12/18/2006] [Indexed: 12/01/2022]
Abstract
Descending vestibular pathways have been shown to influence recruitment thresholds of alpha motoneurones in both human and cat. However, whereas parallel connections to the fusimotor system have been shown in the cat, such connections have not yet been demonstrated in humans. In the present study we investigated whether vestibular inputs can influence the firing of spontaneously active muscle spindles in the leg via activation of gamma motoneurones. Unitary recordings were made from 30 muscle spindle afferents via tungsten microelectrodes inserted percutaneously into the common peroneal nerve of seated awake human subjects. Sinusoidal bipolar binaural galvanic vestibular stimulation (GVS; frequency 0.2, 0.5, 0.8 Hz, amplitude +/-2 mA, 100 cycles) was applied to the mastoid processes. This continuous stimulation produced a sustained frequency-dependent illusion of "rocking in a boat" or "swinging in a hammock". Despite these robust illusions none of the spontaneously active muscle spindles exhibited phase-locked modulation of firing during sinusoidal GVS. We conclude that this dynamic vestibular input was not sufficient to recruit gamma motoneurones, which are known to have little spontaneous activity in relaxed human muscles.
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Affiliation(s)
- Leah R Bent
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON, N1G 2W1 Canada.
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43
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McFadyen BJ, Bouyer L, Bent LR, Inglis JT. Visual-vestibular influences on locomotor adjustments for stepping over an obstacle. Exp Brain Res 2006; 179:235-43. [PMID: 17136529 DOI: 10.1007/s00221-006-0784-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2006] [Accepted: 10/27/2006] [Indexed: 11/30/2022]
Abstract
Combined visual and vestibular influences on locomotor control, particularly in changing environments, are little understood. We studied such influences on body orientation and foot trajectory control during level walking and obstacle avoidance. Six young adults walked on the level and over an obstacle while vision was present or occluded as well as while vestibular information was intact or perturbed using galvanic vestibular stimulation (GVS). The occlusion of vision caused a slowing of gait during obstacle avoidance as well as increased clearance of the leading limb over the obstruction. GVS caused lateral deviations in head and trunk roll angles as well as in foot and trunk displacements, but these lateral deviations were the same during both level walking and obstacle avoidance. In addition, GVS had no effect at all on sagittal plane factors such as speed, foot proximity to the obstacle and vertical clearance over the obstacle. Overall, there is a complex visual control of bilateral obstacle avoidance, but the lack of differences in GVS effects between level and obstructed walking shows that vestibular information is not upregulated for obstacle avoidance. In addition, the robust indifference of anterior foot placement and body displacement to significant lateral deviations from GVS suggests an orthogonally based sensori-locomotor control.
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Macuga KL, Beall AC, Kelly JW, Smith RS, Loomis JM. Changing lanes: inertial cues and explicit path information facilitate steering performance when visual feedback is removed. Exp Brain Res 2006; 178:141-50. [PMID: 17091302 DOI: 10.1007/s00221-006-0718-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2006] [Accepted: 09/14/2006] [Indexed: 10/23/2022]
Abstract
Can driver steering behaviors, such as a lane change, be executed without visual feedback? In a recent study with a fixed-base driving simulator, drivers failed to execute the return phase of a lane change when steering without vision, resulting in systematic final heading errors biased in the direction of the lane change. Here we challenge the generality of that finding. Suppose that, when asked to perform a lane (position) change, drivers fail to recognize that a heading change is required to make a lateral position change. However, given an explicit path, the necessary heading changes become apparent. Here we demonstrate that when heading requirements are made explicit, drivers appropriately implement the return phase. More importantly, by using an electric vehicle outfitted with a portable virtual reality system, we also show that valid inertial information (i.e., vestibular and somatosensory cues) enables accurate steering behavior when vision is absent. Thus, the failure to properly execute a lane change in a driving simulator without a moving base does not present a fundamental problem for feed-forward driving behavior.
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Affiliation(s)
- Kristen L Macuga
- Department of Psychology, University of California, Santa Barbara, CA 93106-9660, USA.
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45
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Fitzpatrick RC, Butler JE, Day BL. Resolving head rotation for human bipedalism. Curr Biol 2006; 16:1509-14. [PMID: 16890526 DOI: 10.1016/j.cub.2006.05.063] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2006] [Revised: 05/29/2006] [Accepted: 05/30/2006] [Indexed: 11/25/2022]
Abstract
Alignment of the body to the gravitational vertical is considered to be the key to human bipedalism. However, changes to the semicircular canals during human evolution suggest that the sense of head rotation that they provide is important for modern human bipedal locomotion. When walking, the canals signal a mix of head rotations associated with path turns, balance perturbations, and other body movements. It is uncertain how the brain uses this information. Here, we show dual roles for the semicircular canals in balance control and navigation control. We electrically evoke a head-fixed virtual rotation signal from semicircular canal nerves as subjects walk in the dark with their head held in different orientations. Depending on head orientation, we can either steer walking by "remote control" or produce balance disturbances. This shows that the brain resolves the canal signal according to head posture into Earth-referenced orthogonal components and uses rotations in vertical planes to control balance and rotations in the horizontal plane to navigate. Because the semicircular canals are concerned with movement rather than detecting vertical alignment, this result shows the importance of movement control and agility rather than precise vertical alignment of the body for human bipedalism.
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Affiliation(s)
- Richard C Fitzpatrick
- Prince of Wales Medical Research Institute and University of New South Wales, Sydney 2031, Australia.
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Deshpande N, Patla AE. Visual–vestibular interaction during goal directed locomotion: effects of aging and blurring vision. Exp Brain Res 2006; 176:43-53. [PMID: 16847610 DOI: 10.1007/s00221-006-0593-5] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2005] [Accepted: 06/10/2006] [Indexed: 10/24/2022]
Abstract
Normal vision overrides perturbed vestibular information for the optimization of performance during goal directed locomotion, suggesting down-regulation of vestibular gain. However, it is not known if the responses to vestibular perturbation are accentuated when vision is impaired. Furthermore, both visual and vestibular systems deteriorate with age. It is not clear, however, how age-related decline in these sensory systems influences visual-vestibular interaction. Therefore, the dual purpose of the present study was to investigate the effects of aging and blurring vision, that simulated the consequences of cataracts, on visual-vestibular interaction. Young and healthy elderly walked to a target located straight ahead with either normal or blurring vision. On randomly selected trials vestibular system perturbation was achieved by applying transmastoidal galvanic vestibular stimulation (GVS). Two different galvanic stimulation intensities were used to provide insight into scaling effect of vestibular perturbation on locomotor performance and how age and vision influences this scaling effect. Maximum path deviation, frontal trunk tilt and postural coordination in the mediolateral direction were evaluated. The magnitude of the path deviation and the trunk tilt response were scaled to the magnitude of the vestibular perturbation in older adults independent of the visual condition. Older participants demonstrated increased coupling of the head and trunk segments irrespective of visual and vestibular perturbations. The results suggest that when visual information was available, the vestibular input reweighting was less effective in older individuals, as shown by the scaled responses to the GVS intensities and the inability to converge efficiently towards the target.
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Affiliation(s)
- Nandini Deshpande
- Gait & Posture Lab, Department of Kinesiology, University of waterloo, Waterloo, ON, Canada.
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Lepecq JC, De Waele C, Mertz-Josse S, Teyssèdre C, Huy PTB, Baudonnière PM, Vidal PP. Galvanic Vestibular Stimulation Modifies Vection Paths in Healthy Subjects. J Neurophysiol 2006; 95:3199-207. [PMID: 16436483 DOI: 10.1152/jn.00478.2005] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The present study aimed at determining whether vestibular inputs contribute to the perception of the direction of self-motion. This question was approached by investigating the effects of binaural bipolar galvanic vestibular stimulation (GVS) on visually induced self-motion (i.e., vection) in healthy subjects. Stationary seated subjects were submitted to optokinetic stimulation inducing either forward or upward linear vection. While perceiving vection, they were administered trapezoidal GVS of different intensities and ramp durations. Subjects indicated the shape and direction of their perceived self-motion path throughout the experiment by a joystick, and after each trial by the manipulation of a 3D mannequin. Results show that: 1) GVS induced alterations of the path of vection; 2) these alterations occurred more often after GVS onset than after GVS offset; 3) the occurrence of vection path alterations after GVS onset depended on the intensity of GVS but not on the steepness of the GVS variation; 4) the vection path deviated laterally according to either an oblique or a curved path; and 5) the vection path deviated toward the cathode side after GVS onset. It is the first time that vestibular information, already known to contribute to the induction of vection, is shown to modify self-motion perception during the course of vection.
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Affiliation(s)
- Jean-Claude Lepecq
- Mouvement et Perception, Centre National de la Recherche Scientifique (CNRS) Unité Mixte de Recherche (UMR) 6152 and Université de la Méditerranée, Faculté des Sciences du Sport, Marseille, France
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Knox JJ, Coppieters MW, Hodges PW. Do you know where your arm is if you think your head has moved? Exp Brain Res 2006; 173:94-101. [PMID: 16565812 DOI: 10.1007/s00221-006-0368-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2005] [Accepted: 01/12/2006] [Indexed: 10/24/2022]
Abstract
Reproduction of a previously presented elbow position is affected by changes in head position. As movement of the head is associated with local biomechanical changes, the aim of the present study was to determine if illusory changes in head position could induce similar effects on the reproduction of elbow position. Galvanic vestibular stimulation (GVS) was applied to healthy subjects in supine lying. The stimulus was applied during the presentation of an elbow position, which the subject then reproduced without stimulation. In the first study, 13 subjects received 1.5 mA stimuli, which caused postural sway in standing, confirming that the firing of vestibular afferents was affected, but no illusory changes in head position were reported. In the second study, 13 subjects received 2.0-3.0 mA GVS. Six out of 13 subjects reported consistent illusory changes in head position, away from the side of the anode. In these subjects, anode right stimulation induced illusory left lateral flexion and elbow joint position error towards extension (p=0.03), while anode left tended to have the opposite effect (p=0.16). The GVS had no effect on error in subjects who did not experience illusory head movement with either 1.5 mA stimulus (p=0.8) or 2.0-3.0 mA stimulus (p=0.7). This study demonstrates that the accuracy of elbow repositioning is affected by illusory changes in head position. These results support the hypothesis that the perceived position of proximal body segments is used in the planning and performance of accurate upper limb movements.
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Affiliation(s)
- Joanna J Knox
- Division of Physiotherapy, School of Health and Rehabilitation Sciences, The University of Queensland, 4072 Brisbane, Qld, Australia
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Courtine G, Papaxanthis C, Schieppati M. Coordinated modulation of locomotor muscle synergies constructs straight-ahead and curvilinear walking in humans. Exp Brain Res 2005; 170:320-35. [PMID: 16328271 DOI: 10.1007/s00221-005-0215-7] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2005] [Accepted: 08/29/2005] [Indexed: 11/28/2022]
Abstract
We describe the muscle synergies accompanying steering of walking along curved trajectories, in order to analyze the simultaneous control of progression and balance-threatening emerging forces. For this purpose, we bilaterally recorded in ten subjects the electromyograms (EMGs) of a representative sample of leg and trunk muscles (n=16) during continuous walking along one straight and two curved trajectories at natural speed. Curvilinear locomotion involved a graded, limb-dependent modulation of amplitude and timing of activity of the muscles of the legs and trunk. The turn-related modulation of the motor pattern was highly coordinated amongst muscles and body sides. For all muscles, linear relationships were detected between the spatial and temporal features of muscle EMG activity. The largest modulation of EMG was observed in gastrocnemius medialis and lateralis muscles, which showed opposite changes in timing and amplitude during curve-walking. Moreover, amplitude and timing characteristics of muscle activities were significantly correlated with the spatial and temporal gait adaptations that are associated with curvilinear locomotion. The present results reveal that fine-modulation of the muscle synergies underlying straight-ahead locomotion is enough to generate the adequate propulsive forces to steer walking and maintain balance. These findings suggest that the turn-related command operates by modulation of the phase relationships between the tightly coupled neuronal assemblies that drive motor neuron activity during walking. This would produce the invariant templates for locomotion kinematics that are at the base of human navigation in space.
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Affiliation(s)
- Grégoire Courtine
- Dipartimento di Medicina Sperimentale, Sezione di Fisiologia, Università di Pavia, Pavia, Italy
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Abstract
This review explores vestibular contributions during dynamic tasks with the goal of identifying the underlying roles of vestibular information in task progression and balance control. Vestibular contributions to upper and lower body control during locomotor tasks were found.
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Affiliation(s)
- Leah R Bent
- Prince of Wales Medical Research Institute Randwick, NSW, Australia.
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