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Monti E, D'Andrea W, Carroll LM, Norton K, Miron N, Resto O, Toscano K, Williams J, Harris D, Irene L, Maass A. Can perpetrators discern survivors from voice? Eur J Psychotraumatol 2024; 15:2358681. [PMID: 38837122 DOI: 10.1080/20008066.2024.2358681] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Accepted: 05/14/2024] [Indexed: 06/06/2024] Open
Abstract
Background: Research has shown that potential perpetrators and individuals high in psychopathic traits tend to body language cues to target a potential new victim. However, whether targeting occurs also by tending to vocal cues has not been examined. Thus, the role of voice in interpersonal violence merits investigation.Objective: In two studies, we examined whether perpetrators could differentiate female speakers with and without sexual and physical assault histories (presented as rating the degree of 'vulnerability' to victimization).Methods: Two samples of male listeners (sample one N = 105, sample two, N = 109) participated. Each sample rated 18 voices (9 survivors and 9 controls). Listener sample one heard spontaneous speech, and listener sample two heard the second sentence of a standardized passage. Listeners' self-reported psychopathic traits and history of previous perpetration were measured.Results: Across both samples, history of perpetration (but not psychopathy) predicted accuracy in distinguishing survivors of assault.Conclusions: These findings highlight the potential role of voice in prevention and intervention. Gaining a further understanding of what voice cues are associated with accuracy in discerning survivors can also help us understand whether or not specialized voice training could have a role in self-defense practices.
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Affiliation(s)
- Elisa Monti
- Voice and Trauma Research and Connection Group, Inc., New York, NY, USA
- Department of Psychology, The New School for Social Research, New York, NY, USA
| | - Wendy D'Andrea
- Department of Psychology, The New School for Social Research, New York, NY, USA
| | | | - Katherine Norton
- Department of Psychology, The New School for Social Research, New York, NY, USA
| | - Noga Miron
- Department of Psychology, The New School for Social Research, New York, NY, USA
| | - Olivia Resto
- Department of Psychology, The New School for Social Research, New York, NY, USA
| | - Kayla Toscano
- Voice and Trauma Research and Connection Group, Inc., New York, NY, USA
- Department of Psychology, The New School for Social Research, New York, NY, USA
| | - John Williams
- Department of Biostatistics, Columbia University, New York, NY, USA
| | | | | | - Anne Maass
- Department of Psychology, New York University Abu Dhabi, Abu Dhabi, UAE
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Hill M, Brayne L, Hosseini E, Duncan M, Muehlbauer T, Lord SR, Ellmers TJ. The influence of fear of falling on the control of upright stance across the lifespan. Gait Posture 2024; 109:226-232. [PMID: 38364509 DOI: 10.1016/j.gaitpost.2024.01.032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Revised: 12/20/2023] [Accepted: 01/25/2024] [Indexed: 02/18/2024]
Abstract
BACKGROUND Standing at height, and subsequent changes in emotional state (e.g., fear of falling), lead to robust alterations in balance in adults. However, little is known about how height-induced postural threat affects balance performance in children. Children may lack the cognitive capability necessary to inhibit the processing of threat and fear-related stimuli, and as a result, may show more marked (and perhaps detrimental) changes in postural control compared to adults. This work explored the emotional and balance responses to standing at height in children, and compared responses to young and older adults. METHODS Children (age: 9.7 ± 0.8 years, n = 38), young adults (age: 21.8 ± 4.0 years, n = 45) and older adults (age: 73.3 ± 5.0 years, n = 15) stood in bipedal stance in two conditions: at ground level and 80 cm above ground. Centre of pressure (COP) amplitude (RMS), frequency (MPF) and complexity (sample entropy) were calculated to infer postural performance and strategy. Emotional responses were quantified by assessing balance confidence, fear of falling and perceived instability. RESULTS Young and older adults demonstrated a postural adaptation characterised by increased frequency and decreased amplitude of the COP, in conjunction with increased COP complexity (sample entropy). In contrast, children demonstrated opposite patterns of changes: they exhibited an increase in COP amplitude and decrease in both frequency and complexity when standing at height. SIGNIFICANCE Children and adults adopted different postural control strategies when standing at height. Whilst young and older adults exhibited a potentially protective "stiffening" response to a height-induced threat, children demonstrated a potentially maladaptive and ineffective postural adaptation strategy. These observations expand upon existing postural threat related research in adults, providing important new insight into understanding how children respond to standing in a hazardous situation.
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Affiliation(s)
- M Hill
- Centre for Physical Activity, Sport and Exercise Sciences, Coventry University, Coventry, United Kingdom.
| | - L Brayne
- Centre for Physical Activity, Sport and Exercise Sciences, Coventry University, Coventry, United Kingdom
| | - E Hosseini
- Centre for Physical Activity, Sport and Exercise Sciences, Coventry University, Coventry, United Kingdom
| | - M Duncan
- Centre for Physical Activity, Sport and Exercise Sciences, Coventry University, Coventry, United Kingdom
| | - T Muehlbauer
- Division of Movement and Training Sciences/Biomechanics of Sport, University of Duisburg-Essen, Essen, Germany
| | - S R Lord
- Falls, Balance and Injury Research Centre, Neuroscience Research Australia, University of New South Wales, Sydney, New South Wales, Australia
| | - T J Ellmers
- Department of Brain Sciences, Imperial College London, London, United Kingdom
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Grove CR, Klatt BN, Wagner AR, Anson ER. Vestibular perceptual testing from lab to clinic: a review. Front Neurol 2023; 14:1265889. [PMID: 37859653 PMCID: PMC10583719 DOI: 10.3389/fneur.2023.1265889] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Accepted: 09/18/2023] [Indexed: 10/21/2023] Open
Abstract
Not all dizziness presents as vertigo, suggesting other perceptual symptoms for individuals with vestibular disease. These non-specific perceptual complaints of dizziness have led to a recent resurgence in literature examining vestibular perceptual testing with the aim to enhance clinical diagnostics and therapeutics. Recent evidence supports incorporating rehabilitation methods to retrain vestibular perception. This review describes the current field of vestibular perceptual testing from scientific laboratory techniques that may not be clinic friendly to some low-tech options that may be more clinic friendly. Limitations are highlighted suggesting directions for additional research.
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Affiliation(s)
- Colin R. Grove
- Department of Otolaryngology Head and Neck Surgery, Johns Hopkins University School of Medicine, Baltimore, MD, United States
- Division of Physical Therapy, Department of Physical Medicine and Rehabilitation School of Medicine, Emory University, Atlanta, GA, United States
| | - Brooke N. Klatt
- Physical Therapy Department, University of Pittsburgh, Pittsburgh, PA, United States
| | - Andrew R. Wagner
- Department of Otolaryngology—Head and Neck Surgery, Ohio State University Wexner Medical Center, Columbus, OH, United States
- School of Health and Rehabilitation Sciences, Ohio State University, Columbus, OH, United States
| | - Eric R. Anson
- Department of Otolaryngology, University of Rochester, Rochester, NY, United States
- Physical Therapy Department, University of Rochester, Rochester, NY, United States
- Department of Neuroscience, University of Rochester, Rochester, NY, United States
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Hall KJ, Van Ooteghem K, McIlroy WE. Emotional state as a modulator of autonomic and somatic nervous system activity in postural control: a review. Front Neurol 2023; 14:1188799. [PMID: 37719760 PMCID: PMC10500443 DOI: 10.3389/fneur.2023.1188799] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Accepted: 08/07/2023] [Indexed: 09/19/2023] Open
Abstract
Advances in our understanding of postural control have highlighted the need to examine the influence of higher brain centers in the modulation of this complex function. There is strong evidence of a link between emotional state, autonomic nervous system (ANS) activity and somatic nervous system (somatic NS) activity in postural control. For example, relationships have been demonstrated between postural threat, anxiety, fear of falling, balance confidence, and physiological arousal. Behaviorally, increased arousal has been associated with changes in velocity and amplitude of postural sway during quiet standing. The potential links between ANS and somatic NS, observed in control of posture, are associated with shared neuroanatomical connections within the central nervous system (CNS). The influence of emotional state on postural control likely reflects the important influence the limbic system has on these ANS/somatic NS control networks. This narrative review will highlight several examples of behaviors which routinely require coordination between the ANS and somatic NS, highlighting the importance of the neurofunctional link between these systems. Furthermore, we will extend beyond the more historical focus on threat models and examine how disordered/altered emotional state and ANS processing may influence postural control and assessment. Finally, this paper will discuss studies that have been important in uncovering the modulatory effect of emotional state on postural control including links that may inform our understanding of disordered control, such as that observed in individuals living with Parkinson's disease and discuss methodological tools that have the potential to advance understanding of this complex relationship.
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Affiliation(s)
- Karlee J. Hall
- Department of Kinesiology and Health Sciences, University of Waterloo, Waterloo, ON, Canada
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Fischer OM, Missen KJ, Tokuno CD, Carpenter MG, Adkin AL. Postural threat increases sample entropy of postural control. Front Neurol 2023; 14:1179237. [PMID: 37342783 PMCID: PMC10277644 DOI: 10.3389/fneur.2023.1179237] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Accepted: 05/12/2023] [Indexed: 06/23/2023] Open
Abstract
Introduction Postural threat elicits modifications to standing balance. However, the underlying neural mechanism(s) responsible remain unclear. Shifts in attention focus including directing more attention to balance when threatened may contribute to the balance changes. Sample entropy, a measure of postural sway regularity with lower values reflecting less automatic and more conscious control of balance, may support attention to balance as a mechanism to explain threat-induced balance changes. The main objectives were to investigate the effects of postural threat on sample entropy, and the relationships between threat-induced changes in physiological arousal, perceived anxiety, attention focus, sample entropy, and traditional balance measures. A secondary objective was to explore if biological sex influenced these relationships. Methods Healthy young adults (63 females, 42 males) stood quietly on a force plate without (No Threat) and with (Threat) the expectation of receiving a postural perturbation (i.e., forward/backward support surface translation). Mean electrodermal activity and anterior-posterior centre of pressure (COP) sample entropy, mean position, root mean square, mean power frequency, and power within low (0-0.05 Hz), medium (0.5-1.8 Hz), and high-frequency (1.8-5 Hz) components were calculated for each trial. Perceived anxiety and attention focus to balance, task objectives, threat-related stimuli, self-regulatory strategies, and task-irrelevant information were rated after each trial. Results and Discussion Significant threat effects were observed for all measures, except low-frequency sway. Participants were more physiologically aroused, more anxious, and directed more attention to balance, task objectives, threat-related stimuli, and self-regulatory strategies, and less to task-irrelevant information in the Threat compared to No Threat condition. Participants also increased sample entropy, leaned further forward, and increased the amplitude and frequency of COP displacements, including medium and high-frequency sway, when threatened. Males and females responded in the same way when threatened, except males had significantly larger threat-induced increases in attention to balance and high-frequency sway. A combination of sex and threat-induced changes in physiological arousal, perceived anxiety, and attention focus accounted for threat-induced changes in specific traditional balance measures, but not sample entropy. Increased sample entropy when threatened may reflect a shift to more automatic control. Directing more conscious control to balance when threatened may act to constrain these threat-induced automatic changes to balance.
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Affiliation(s)
- Olivia M. Fischer
- Department of Kinesiology, Brock University, St. Catharines, ON, Canada
| | - Kyle J. Missen
- School of Kinesiology, University of British Columbia, Vancouver, BC, Canada
| | - Craig D. Tokuno
- Department of Kinesiology, Brock University, St. Catharines, ON, Canada
| | - Mark G. Carpenter
- School of Kinesiology, University of British Columbia, Vancouver, BC, Canada
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, Canada
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, BC, Canada
| | - Allan L. Adkin
- Department of Kinesiology, Brock University, St. Catharines, ON, Canada
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Hill MW, Russel K, Wdowski M, Lord SR, Muehlbauer T, Ellmers T. Effects of arm movement strategies on emotional state and balance control during height-induced postural threat in young adults. Gait Posture 2023; 103:73-79. [PMID: 37121215 DOI: 10.1016/j.gaitpost.2023.04.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Revised: 04/11/2023] [Accepted: 04/26/2023] [Indexed: 05/02/2023]
Abstract
BACKGROUND It is firmly established that postural threat seems to lead to an increased. reliance on an ankle control ('stiffening') strategy. However, little is known about how. postural threat affects performance in challenging tasks that require the use of upper. body postural control strategies for stability. It is logical to assume that in such. conditions, being able to utilise an upper body strategy may reduce the reliance on. such ankle stiffening strategy. Research question The objective of this study was to determine how arm movement. influences balance control during a challenging balance task performed under. conditions of postural threat. METHODS Thirty young adults (mean ± SD age; 22.0 ± 4.0 years) balanced in tandem. stance whilst standing at both ground-level (no threat) and 0.8 m above ground. (threat). In both conditions, participants performed the task under two different arm. POSITIONS restricted arm movements and free arm movements. Postural sway. amplitude and frequency were calculated to infer postural stiffening response. Selfreported. emotional responses were quantified by assessing balance confidence, fear. of falling, perceived stability, and conscious balance processing. RESULTS Independent of arm movements, postural threat evoked an increase in fear of. falling and conscious balance processing, and reductions in balance confidence and. perceived stability. These threat-related changes in emotional state were further. amplified when arm movements were restricted. Whilst significant increases in sway. frequency during threat were observed in both arm conditions, reductions in sway. amplitude were only observed during the restricted arm movement condition. SIGNIFICANCE We propose that these responses likely reflect a fear-related cautious. strategy intended to reduce the postural destabilisation associated with individuals. being unable to use their arms to counter any destabilisation, as would normally be the. case in daily life.
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Affiliation(s)
- M W Hill
- Centre for Sport, Exercise and Life Sciences, Coventry University, Coventry, United Kingdom.
| | - K Russel
- Centre for Sport, Exercise and Life Sciences, Coventry University, Coventry, United Kingdom
| | - M Wdowski
- Centre for Sport, Exercise and Life Sciences, Coventry University, Coventry, United Kingdom
| | - S R Lord
- Falls, Balance and Injury Research Centre, Neuroscience Research Australia, University of New South Wales, Sydney, NSW, Australia
| | - T Muehlbauer
- Division of Movement and Training Sciences/Biomechanics of Sport, University of Duisburg-Essen, Essen, Germany
| | - T Ellmers
- Department of Brain Sciences, Imperial College London, London, United Kingdom
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Hodgson DD, King JA, Darici O, Dalton BH, Cleworth TW, Cluff T, Peters RM. Visual feedback-dependent modulation of arousal, postural control, and muscle stretch reflexes assessed in real and virtual environments. Front Hum Neurosci 2023; 17:1128548. [PMID: 37082148 PMCID: PMC10110857 DOI: 10.3389/fnhum.2023.1128548] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Accepted: 03/14/2023] [Indexed: 04/07/2023] Open
Abstract
IntroductionThe mechanisms regulating neuromuscular control of standing balance can be influenced by visual sensory feedback and arousal. Virtual reality (VR) is a cutting-edge tool for probing the neural control of balance and its dependence on visual feedback, but whether VR induces neuromodulation akin to that seen in real environments (eyes open vs. closed or ground level vs. height platform) remains unclear.MethodsHere we monitored 20 healthy young adults (mean age 23.3 ± 3.2 years; 10 females) during four conditions of quiet standing. Two real world conditions (eyes open and eyes closed; REO and REC) preceded two eyes-open virtual ‘low’ (ground level; VRL) and ‘high’ (14 m height platform; VRH) conditions. We measured arousal via electrodermal activity and psychosocial questionnaires rating perceived fear and anxiety. We recorded surface electromyography over the right soleus, medial gastrocnemius, and tibialis anterior, and performed force plate posturography. As a proxy for modulations in neural control, we assessed lower limb reflexive muscle responses evoked by tendon vibration and electrical stimulation.ResultsPhysiological and perceptual indicators of fear and anxiety increased in the VRH condition. Background soleus muscle activation was not different across conditions; however, significant increases in muscle activity were observed for medial gastrocnemius and tibialis anterior in VRH relative to REO. The mean power frequency of postural sway also increased in the VRH condition relative to REO. Finally, with a fixed stimulus level across conditions, mechanically evoked reflexes remained constant, while H-reflex amplitudes decreased in strength within virtual reality.DiscussionNotably, H-reflexes were lower in the VRL condition than REO, suggesting that these ostensibly similar visual environments produce different states of reflexive balance control. In summary, we provide novel evidence that VR can be used to modulate upright postural control, but caution that standing balance in analogous real and virtual environments may involve different neural control states.
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Affiliation(s)
| | - Jordan A. King
- Biomedical Engineering, University of Calgary, Calgary, AB, Canada
| | - Osman Darici
- Faculty of Kinesiology, University of Calgary, Calgary, AB, Canada
| | - Brian H. Dalton
- School of Health and Exercise Sciences, University of British Columbia Okanagan, Kelowna, BC, Canada
| | | | - Tyler Cluff
- Faculty of Kinesiology, University of Calgary, Calgary, AB, Canada
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada
| | - Ryan M. Peters
- Faculty of Kinesiology, University of Calgary, Calgary, AB, Canada
- Biomedical Engineering, University of Calgary, Calgary, AB, Canada
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada
- *Correspondence: Ryan M. Peters,
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8
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Elboim-Gabyzon M, Pitluk M, Shuper Engelhard E. The correlation between physical and emotional stabilities: a cross-sectional observational preliminary study. Ann Med 2022; 54:1678-1685. [PMID: 35695561 PMCID: PMC9225739 DOI: 10.1080/07853890.2022.2056241] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
BACKGROUND Postural stability and gait are affected by an individual's emotional state. Physical therapy practice does not usually include an explicit assessment of the individual's emotional status. In contrast, complementary movement therapies often include the assessment of "grounding quality", which refers to the individual's physical and emotional stabilities. This study examined the correlation between conventional physical stability measures and grounding quality. METHOD A computerized balance board and an inertial sensor system measured the postural stability and gait parameters of 36 healthy volunteers (aged 19-35 years). Grounding was assessed using an observation-based assessment tool (Grounding Assessment Tool [GAT]). Spearman's correlation and Cohen's standard were used to assess correlation. RESULTS No correlation was observed between gait parameters and GAT scores. However, significant negative moderate correlations were noted between postural sway measures and scores of several GAT items in the more demanding stance conditions. CONCLUSION Although grounding quality and sway measures are somewhat correlated, they focus on different aspects of movement stability. A comprehensive assessment and holistic intervention strategies require incorporating multiple approaches to stability assessment. Further research is necessary to determine the contribution of combining these approaches among individuals with balance impairments.KEY MESSAGESGait stability measures were not correlated to "grounding quality" (a measure of emotional regulation and emotional awareness).Postural sway measures were found to be correlated to "grounding quality" items in the more demanding stance conditions.A comprehensive evaluation of an individual's stability may facilitate reliable and valid objective measurement instruments for both physical and emotional aspects of the movement.
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Affiliation(s)
- Michal Elboim-Gabyzon
- Physical Therapy Department, Faculty of Social Welfare & Health Sciences, University of Haifa, Haifa, Israel
| | - Michal Pitluk
- Faculty of Social Welfare & Health Sciences, Graduate School of Creative Art Therapies, Emili Sagol Creative Arts Therapies Research Center, University of Haifa, Haifa, Israel
| | - Einat Shuper Engelhard
- Faculty of Social Welfare & Health Sciences, Graduate School of Creative Art Therapies, Emili Sagol Creative Arts Therapies Research Center, University of Haifa, Haifa, Israel.,Faculty of Humanities & Social Sciences, Graduate School of Creative Art Therapies, Kibbutzim College of Education, Tel Aviv, Israel
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Nielsen EI, Cleworth TW, Carpenter MG. Exploring emotional-modulation of visually evoked postural responses through virtual reality. Neurosci Lett 2022; 777:136586. [PMID: 35331814 DOI: 10.1016/j.neulet.2022.136586] [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: 11/09/2021] [Revised: 03/08/2022] [Accepted: 03/18/2022] [Indexed: 11/19/2022]
Abstract
Exposure to postural threat has been documented to influence the sensory contributions of proprioceptive and vestibular information in standing balance control. Contributions from the visual system to balance are also crucial, yet the degree to which postural threat may modulate visual control of balance is not well characterized. Therefore, the aims of this study were to assess the feasibility of eliciting visual evoked postural responses (VEPRs) using head-mounted virtual reality (VR) and use this method to examine the potential influence of virtual postural threat on the visual control of balance. 36 healthy young adults were exposed to a pseudorandom, translational visual stimulus of a real-world environment in VR. The visual stimulus was presented in virtual conditions of LOW and HIGH postural threat in which participants stood at ground level, and on a 7m elevated platform, respectively. VEPRs were successfully produced in both postural threat conditions. When exposed to the visual stimulus while at an elevated surface height, participants demonstrated significant changes to their physiological arousal and emotional state. Despite significant coherence across the stimulus' frequency range, stimulus correlated VEPRs were not significantly modulated during exposure to the visual stimulus under virtual postural threat. This study supports the future utility of VR head-mounted displays in examining emotional influences on the visual control of balance.
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Affiliation(s)
- Emma I Nielsen
- School of Kinesiology, University of British Columbia, Vancouver, BC, Canada; Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Taylor W Cleworth
- School of Kinesiology, University of British Columbia, Vancouver, BC, Canada; School of Kinesiology and Health Science, York University, Toronto, ON, Canada
| | - Mark G Carpenter
- School of Kinesiology, University of British Columbia, Vancouver, BC, Canada; Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, Canada; International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, BC, Canada.
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Zaback M, Adkin AL, Chua R, Timothy Inglis J, Carpenter MG. Facilitation and habituation of cortical and subcortical control of standing balance following repeated exposure to a height-related postural threat. Neuroscience 2022; 487:8-25. [DOI: 10.1016/j.neuroscience.2022.01.012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2021] [Revised: 12/23/2021] [Accepted: 01/17/2022] [Indexed: 01/21/2023]
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11
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Jeon W, Griffin L, Hsiao HY. Effects of initial foot position on postural responses to lateral standing surface perturbations in younger and older adults. Gait Posture 2021; 90:449-456. [PMID: 34600179 DOI: 10.1016/j.gaitpost.2021.09.193] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/10/2021] [Revised: 09/07/2021] [Accepted: 09/21/2021] [Indexed: 02/02/2023]
Abstract
BACKGROUND An age-related decline in standing balance control in the medio-lateral direction is associated with increased risk of falls. A potential approach to improve postural stability is to change initial foot position (IFP). RESEARCH QUESTIONS In response to a lateral surface perturbation, how are lower extremity muscle activation levels different and what are the effects of different IFPs on muscle activation patterns and postural stability in younger versus older adults? METHODS Ten younger and ten older healthy adults participated in this study. Three IFPs were tested [Reference (REF): feet were placed parallel, shoulder-width apart; Toes-out with heels together (TOHT): heels together with toes pointing outward; Modified Semi-Tandem (M-ST): the heel of the anterior foot was placed by the big toe of the posterior foot]. Unexpected lateral translations of the standing surface were applied. Electromyographic (EMG) activity of the lower extremity muscles, standard deviation (SD) of the body's CoM acceleration (SD of CoMAccel), and center of pressure (CoP) sway area were compared across IFPs and age. RESULTS Activation levels of the muscles serving the ankle and gluteus medius were greater than for the knee joint muscles and gluteus maximus in the loaded leg across all IFPs in both groups. TOHT showed greater EMG peak amplitude of the soleus and fibularis longus compared to REF, and had smaller SD of CoMAccel and CoP sway area than M-ST. Compared to younger adults, older adults demonstrated lower EMG peak amplitude and delayed peak timing of the fibularis longus and greater SD of CoMAccel and CoP sway area in all IFPs during balance recovery. SIGNIFICANCE During standing balance recovery, ankle muscles and gluteus medius are important active responders to unexpected lateral surface perturbations and a toes-out IFP could be a viable option to enhance ankle muscle activation that diminishes with age to improve postural stability.
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Affiliation(s)
- Woohyoung Jeon
- Department of Kinesiology and Health Education, 2109 San Jacinto Blvd, D3700, University of Texas at Austin, Austin, TX, 78712, USA.
| | - Lisa Griffin
- Department of Kinesiology and Health Education, 2109 San Jacinto Blvd, D3700, University of Texas at Austin, Austin, TX, 78712, USA.
| | - Hao-Yuan Hsiao
- Department of Kinesiology and Health Education, 2109 San Jacinto Blvd, D3700, University of Texas at Austin, Austin, TX, 78712, USA.
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