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Hill MW, Johnson E, Ellmers TJ. The influence of false interoceptive feedback on emotional state and balance responses to height-induced postural threat. Biol Psychol 2024; 189:108803. [PMID: 38663458 DOI: 10.1016/j.biopsycho.2024.108803] [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: 09/12/2023] [Revised: 03/01/2024] [Accepted: 04/18/2024] [Indexed: 06/19/2024]
Abstract
Postural threat elicits a robust emotional response (e.g., fear and anxiety about falling), with concomitant modifications in balance. Recent theoretical accounts propose that emotional responses to postural threats are manifested, in part, from the conscious monitoring and appraisal of bodily signals ('interoception'). Here, we empirically probe the role of interoception in shaping emotional responses to a postural threat by experimentally manipulating interoceptive cardiac feedback. Sixty young adults completed a single 60-s trial under the following conditions: Ground (no threat) without heart rate (HR) feedback, followed by Threat (standing on the edge of a raised surface), during which participants received either false heart rate feedback (either slow [n = 20] or fast [n = 20] HR feedback) or no feedback (n = 20). Participants provided with false fast HR feedback during postural threat felt more fearful, reported feeling less stable, and rated the task more difficult than participants who did not receive HR feedback, or those who received false slow HR feedback (Cohen's d effect size = 0.79 - 1.78). However, behavioural responses did not significantly differ across the three groups. When compared to the no HR feedback group, false slow HR feedback did not significantly affect emotional or behavioural responses to the postural threat. These observations provide the first experimental evidence for emerging theoretical accounts describing the role of interoception in the generation of emotional responses to postural threats.
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Affiliation(s)
- Mathew W Hill
- Centre for Physical Activity, Sport and Exercise Sciences, Coventry University, Warwickshire, United Kingdom.
| | - Ellie Johnson
- Centre for Physical Activity, Sport and Exercise Sciences, Coventry University, Warwickshire, United Kingdom
| | - Toby J Ellmers
- Department of Brain Sciences, Imperial College London, London, United Kingdom
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2
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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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3
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Ellmers TJ, Wilson MR, Kal EC, Young WR. The perceived control model of falling: developing a unified framework to understand and assess maladaptive fear of falling. Age Ageing 2023; 52:afad093. [PMID: 37466642 PMCID: PMC10355179 DOI: 10.1093/ageing/afad093] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Indexed: 07/20/2023] Open
Abstract
BACKGROUND fear of falling is common in older adults and can have a profound influence on a variety of behaviours that increase fall risk. However, fear of falling can also have potentially positive outcomes for certain individuals. Without progressing our understanding of mechanisms underlying these contrasting outcomes, it is difficult to clinically manage fear of falling. METHODS this paper first summarises recent findings on the topic of fear of falling, balance and fall risk-including work highlighting the protective effects of fear. Specific focus is placed on describing how fear of falling influences perceptual, cognitive and motor process in ways that might either increase or reduce fall risk. Finally, it reports the development and validation of a new clinical tool that can be used to assess the maladaptive components of fear of falling. RESULTS we present a new conceptual framework-the Perceived Control Model of Falling-that describes specific mechanisms through which fear of falling can influence fall risk. The key conceptual advance is the identification of perceived control over situations that threaten one's balance as the crucial factor mediating the relationship between fear and increased fall risk. The new 4-item scale that we develop-the Updated Perceived Control over Falling Scale (UP-COF)-is a valid and reliable tool to clinically assess perceived control. CONCLUSION this new conceptualisation and tool (UP-COF) allows clinicians to identify individuals for whom fear of falling is likely to increase fall risk, and target specific underlying maladaptive processes such as low perceived control.
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Affiliation(s)
| | - Mark R Wilson
- Department of Public Health and Sports Sciences, University of Exeter, Exeter, UK
| | - Elmar C Kal
- Centre for Cognitive Neuroscience, Brunel University London, London, UK
| | - William R Young
- Centre for Cognitive Neuroscience, Brunel University London, London, UK
- Department of Public Health and Sports Sciences, University of Exeter, Exeter, UK
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4
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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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Song H, Gao R, Zhang Q, Li Y. The nonlinear effect of time pressure on innovation performance: New insights from a meta-analysis and an empirical study. Front Psychol 2023; 13:1049174. [PMID: 36698585 PMCID: PMC9868248 DOI: 10.3389/fpsyg.2022.1049174] [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: 09/20/2022] [Accepted: 12/19/2022] [Indexed: 01/11/2023] Open
Abstract
As competition grows, when employees are required to accelerate innovation, they also face increasing time pressure. In order to shed light on how time pressure affects employees' innovation performance, two studies were conducted to examine the effect of time pressure on innovation performance. In Study 1, based on 50 effect sizes from 50 independent samples (N = 15,751) in 40 articles, a meta-analysis was conducted to examine the J-shaped effect of time pressure on innovation performance. In Study 2, based on a two-wave survey of 645 employees, the mechanism underlying the J-shaped effect of time pressure on innovation performance was explored. Results from Study 1 revealed that time pressure had a J-shaped effect on innovation performance, such that high levels of time pressure had a more positive effect on innovation performance. Results from Study 2 showed that learning behavior significantly mediated the J-shaped effect of time pressure on innovation performance, and that supervisor developmental feedback moderated the intermediary process. These results deepen the understanding of the relationship between time pressure and innovation performance, and provide practical advice on how to manage innovation performance under time pressure.
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Affiliation(s)
- Haojie Song
- School of Business, Zhengzhou University, Zhengzhou, Henan, China
| | - Renjing Gao
- School of Business, Zhengzhou University, Zhengzhou, Henan, China
| | - Qiang Zhang
- Shenzhen Health Development Research and Data Management Center, Shenzhen, China,*Correspondence: Qiang Zhang, ✉
| | - Yongxin Li
- Department of Health Policy Research, Henan University, Kaifeng, Henan, China
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6
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Yin JT, Hu YY, Li QY, Luo JL. Human creativity escapes in the struggle against threat:Evidence from neural mechanisms. Biol Psychol 2022; 172:108359. [DOI: 10.1016/j.biopsycho.2022.108359] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Revised: 05/16/2022] [Accepted: 05/19/2022] [Indexed: 11/29/2022]
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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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Gorjan D, Šarabon N, Babič J. Inter-Individual Variability in Postural Control During External Center of Mass Stabilization. Front Physiol 2022; 12:722732. [PMID: 35046834 PMCID: PMC8761977 DOI: 10.3389/fphys.2021.722732] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Accepted: 11/30/2021] [Indexed: 11/30/2022] Open
Abstract
Understanding the relation between the motion of the center of mass (COM) and the center of pressure (COP) is important to understand the underlying mechanisms of maintaining body equilibrium. One way to investigate this is to stabilize COM by fixing the joints of the human and looking at the corresponding COP reactions. However, this approach constrains the natural motion of the human. To avoid this shortcoming, we stabilized COM without constraining the joint movements by using an external stabilization method based on inverted cart-pendulum system. Interestingly, this method only stabilized COM of a subgroup of participants and had a destabilizing effect for others which implies significant variability in inter-individual postural control. The aim of this work was to investigate the underlying causes of inter-individual variability by studying the postural parameters of quiet standing before the external stabilization. Eighteen volunteers took part in the experiment where they were standing on an actuated cart for 335 s. In the middle of this period we stabilized their COM in anteroposterior direction for 105 s. To stabilize the COM, we controlled the position of the cart using a double proportional–integral–derivative controller. We recorded COM position throughout the experiment, calculated its velocity, amplitude, and frequency during the quiet standing before the stabilization, and used these parameters as features in hierarchical clustering method. Clustering solution revealed that postural parameters of quiet standing before the stabilization cannot explain the inter-individual variability of postural responses during the external COM stabilization. COM was successfully stabilized for a group of participants but had a destabilizing effect on the others, showing a variability in individual postural control which cannot be explained by postural parameters of quiet-stance.
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Affiliation(s)
- Daša Gorjan
- Department of Automation, Biocybernetics and Robotics, Laboratory for Neuromechanics and Biorobotics, Jožef Stefan Institute, Ljubljana, Slovenia
| | - Nejc Šarabon
- Faculty of Health Sciences and Andrej Marušicˇ Institute, University of Primorska, Koper, Slovenia.,InnoRenew CoE, Izola, Slovenia.,S2P, Science to Practice, d.o.o., Laboratory for Motor Control and Motor Behavior, Ljubljana, Slovenia
| | - Jan Babič
- Department of Automation, Biocybernetics and Robotics, Laboratory for Neuromechanics and Biorobotics, Jožef Stefan Institute, Ljubljana, Slovenia.,Faculty of Electrical Engineering, University of Ljubljana, Ljubljana, Slovenia
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9
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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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10
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Amiaz R, Kimel Naor S, Caspi A, Czerniak E, Noy S, Pelc T, Mintz M, Plotnik M. Responses to balance challenges in persons with panic disorder: A pilot study of computerized static and dynamic balance measurements. Brain Behav 2022; 12:e2411. [PMID: 34843172 PMCID: PMC8785611 DOI: 10.1002/brb3.2411] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Revised: 08/22/2021] [Accepted: 09/05/2021] [Indexed: 11/08/2022] Open
Abstract
INTRODUCTION Several studies have shown an association between panic disorder (PD) and reduced balance abilities, mainly based on functional balance scales. This pilot study aims to demonstrate the feasibility of studying balance abilities of persons with PD (PwPD) using computerized static and, for the first time, dynamic balance measurements in order to characterize balance control strategies employed by PwPD. METHODS Twelve PwPD and 11 healthy controls were recruited. PD diagnosis was confirmed using the Diagnostic and Statistical Manual of Mental Disorders, fourth edition (DSM-IV), and the severity of symptoms was evaluated using the Hamilton Anxiety Scale (HAM-A), PD Severity Scales (PDSS), and Panic and Agoraphobia Scale (PAS). Balance was clinically assessed using the Activities-Specific Balance Confidence (ABC) scale and physically by the Mini-Balance Evaluation Systems Test (Mini-BESTest). Dizziness was evaluated using the Dizziness Handicap Inventory (DHI) scale. Postural control was evaluated statically by measuring body sway and dynamically by measuring body responses to rapid unexpected physical perturbations. RESULTS PwPD had higher scores on the HAM-A (17.6 ± 10.3 vs. 3.0 ± 2.9; p < .001), PDSS (11.3 ± 5.1 vs. 0; p < .001), and PAS (20.3 ± 8.7 vs. 0; p < .001) questionnaires and lower scores on the balance scales compared to the controls (ABC scale: 156.2 ± 5.9 vs. 160 ± 0.0, p = .016; Mini-BESTest: 29.4 ± 2.1 vs. 31.4 ± 0.9, p = .014; DHI: 5.3 ± 4.4 vs. 0.09 ± 0.3, p < .001). In the static balance tests, PwPD showed a not-significantly smaller ellipse area of center of pressure trajectory (p = .36) and higher body sway velocity (p = .46), whereas in the dynamic balance tests, PwPD had shorter recovery time from physical perturbations in comparison to controls (2.1 ± 1.2s vs. 1.6 ± 0.9 s, p = .018). CONCLUSION The computerized balance tests results point to an adoption of a ''postural rigidity'' strategy by the PwPD, that is, reduced dynamic adaptations in the face of postural challenges. This may reflect a nonsecure compensatory behavior. Further research is needed to delineate this strategy.
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Affiliation(s)
- Revital Amiaz
- Psychiatry Department, The Chaim Sheba Medical Center, Tel Hashomer, Israel.,Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Shani Kimel Naor
- The Center of Advanced Technologies in Rehabilitation, The Chaim Sheba Medical Center, Tel Hashomer, Israel
| | - Asaf Caspi
- Psychiatry Department, The Chaim Sheba Medical Center, Tel Hashomer, Israel.,Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Efrat Czerniak
- Psychiatry Department, The Chaim Sheba Medical Center, Tel Hashomer, Israel.,Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Shlomo Noy
- Psychiatry Department, The Chaim Sheba Medical Center, Tel Hashomer, Israel.,Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Tatiana Pelc
- School of Psychological Sciences, Tel Aviv University, Tel Aviv, Israel.,Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Matti Mintz
- School of Psychological Sciences, Tel Aviv University, Tel Aviv, Israel.,Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Meir Plotnik
- The Center of Advanced Technologies in Rehabilitation, The Chaim Sheba Medical Center, Tel Hashomer, Israel.,Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel.,Department of Physiology and Pharmacology, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
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11
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Zaback M, Reiter ER, Adkin AL, Carpenter MG. Initial experience of balance assessment introduces 'first trial' effects on emotional state and postural control. Gait Posture 2021; 88:116-121. [PMID: 34034022 DOI: 10.1016/j.gaitpost.2021.05.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 05/02/2021] [Accepted: 05/11/2021] [Indexed: 02/02/2023]
Abstract
BACKGROUND Anxiety and arousal have been shown to influence balance control and, therefore, have the potential to confound balance assessment. It has been suggested that the 'first-trial' effect, where performance on the first trial of a balance task differs from subsequent trials, may be a result of participants being more anxious during their first experience of having their balance assessed. However, this remains speculative since limited work has simultaneously examined emotional state and balance control during repeated assessment of the same balance task. RESEARCH QUESTION Determine how emotional state and standing balance control change over the course of repeated assessment. METHODS Seventy-five healthy young adults completed five 120-s quiet standing trials. Psychological state was probed at each trial using self-report measures that assessed confidence, anxiety, and attention focus. Arousal was estimated from electrodermal activity and balance control was assessed from centre of pressure (COP) measures derived from forceplate data. Repeated measures ANOVAs were conducted to determine how each of these estimates changed with repeated testing. RESULTS There were significant changes in emotional state with repeated testing; self-report and autonomic measures indicated that participants were most anxious and physiologically aroused during the first trial. This emotional response diminished with repeated testing, although the greatest changes occurred from the first to second trial. Despite these changes in emotional state, only some COP outcomes significantly changed. Individuals leaned further forward during only the first trial and demonstrated higher frequency and velocity mediolateral COP oscillations during the first two trials. SIGNIFICANCE When balance is assessed for the first time in an unfamiliar laboratory setting, there is a transient emotional response which appears sufficient to influence some aspects of balance control. It is critical to control for these confounds when designing experiments or interventions involving balance assessment.
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Affiliation(s)
- Martin Zaback
- School of Kinesiology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Emma R Reiter
- School of Kinesiology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Allan L Adkin
- Department of Kinesiology, Brock University, St. Catharines, Ontario, Canada
| | - Mark G Carpenter
- School of Kinesiology, University of British Columbia, Vancouver, British Columbia, Canada; Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, British Columbia, Canada; International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, British Columbia, Canada.
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12
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Nestico J, Novak A, Perry SD, Mansfield A. Does increased gait variability improve stability when faced with an expected balance perturbation during treadmill walking? Gait Posture 2021; 86:94-100. [PMID: 33711616 DOI: 10.1016/j.gaitpost.2021.03.014] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Revised: 02/04/2021] [Accepted: 03/07/2021] [Indexed: 02/02/2023]
Abstract
BACKGROUND Currently, there is uncertainty as to whether movement variability is errorful or exploratory. RESEARCH QUESTION This study aimed to determine if gait variability represents exploration to improve stability. We hypothesized that 1) spatiotemporal gait features will be more variable prior to an expected perturbation than during unperturbed walking, and 2) increased spatiotemporal gait variability pre-perturbation will correlate with improved stability post-perturbation. METHODS Sixteen healthy young adults completed 15 treadmill walking trials within a motion simulator under two conditions: unperturbed and expecting a perturbation. Participants were instructed not to expect a perturbation for unperturbed trials, and to expect a single transient medio-lateral balance perturbation for perturbed trials. Kinematic data were collected during the trials. Twenty steps were recorded post-perturbation. Unperturbed and pre-perturbation gait variabilities were defined by the short- and long-term variabilities of step length, width, and time, using 100 steps from pre-perturbation and unperturbed trials. Paired t-tests identified between-condition differences in variabilities. Stability was defined as the number of steps to centre of mass restabilization post-perturbation. Multiple regression analyses determined the effect of pre-perturbation variability on stability. RESULTS Long-term step width variability was significantly higher pre-perturbation compared to unperturbed walking (mean difference = 0.28 cm, p = 0.0073), with no significant differences between conditions for step length or time variabilities. There was no significant relationship between pre-perturbation variability and post-perturbation restabilization. SIGNIFICANCE Increased pre-perturbation step width variability was neither beneficial nor detrimental to stability. However, the increased variability in medio-lateral foot placement suggests that participants adopted an exploratory strategy in anticipation of a perturbation.
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Affiliation(s)
- Jacqueline Nestico
- University of Toronto, Toronto, ON, Canada; KITE-Toronto Rehabilitation Institute, University Health Network, Toronto, ON, Canada
| | - Alison Novak
- University of Toronto, Toronto, ON, Canada; KITE-Toronto Rehabilitation Institute, University Health Network, Toronto, ON, Canada
| | - Stephen D Perry
- University of Toronto, Toronto, ON, Canada; KITE-Toronto Rehabilitation Institute, University Health Network, Toronto, ON, Canada; Wilfrid Laurier University, Waterloo, ON, Canada
| | - Avril Mansfield
- University of Toronto, Toronto, ON, Canada; KITE-Toronto Rehabilitation Institute, University Health Network, Toronto, ON, Canada; Evaluative Clinical Sciences, Hurvitz Brain Sciences Program, Sunnybrook Research Institute, Toronto, ON, Canada.
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Thomas NM, Skervin TK, Foster RJ, Parr JV, Carpenter MG, O'Brien TD, Maganaris CN, Baltzopoulos V, Lees C, Hollands MA. Influence of step-surface visual properties on confidence, anxiety, dynamic stability, and gaze behaviour in young and older adults. Hum Mov Sci 2021; 77:102774. [PMID: 33676032 DOI: 10.1016/j.humov.2021.102774] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Revised: 02/10/2021] [Accepted: 02/16/2021] [Indexed: 11/16/2022]
Abstract
BACKGROUND Step-surface visual properties are often associated with stair falls. However, evidence for decorating stairs typically concerns the application of step-edge highlighters rather than the entire step-surface. Here we examine the influence of step-surface visual properties on stair descent safety, with a view to generating preliminary evidence for safe stair décor. METHODS Fourteen young (YA: 23.1 ± 3.7 years), 13 higher (HAOA: 67 ± 3.5) and 14 lower (LAOA: 73.4 ± 5.7) ability older adults descended a seven-step staircase. Older adults were stratified based on physiological/cognitive function. Step-surface décor patterns assessed were: Black and white (Busy); fine grey (Plain); and striped multicolour (Striped); each implemented with/without black edge-highlighters (5.5 cm width) totalling six conditions. Participants descended three times per condition. Confidence was assessed prior to, and anxiety following, the first descent in each condition. 3D kinematics (Vicon) quantified descent speed, margin of stability, and foot clearances with respect to step-edges. Eye tracking (Pupil-labs) recorded gaze. Data from three phases of descent (entry, middle, exit) were analysed. Linear mixed-effects models assessed within-subject effects of décor (×3) and edge highlighters (×2), between-subject effects of age (×3), and interactions between terms (α = p < .05). RESULTS Décor: Plain décor reduced anxiety in all ages and abilities (p = .032, effect size: gav = 0.3), and increased foot clearances in YA and HAOA in the middle phase (p < .001, gav = 0.53), thus improving safety. In contrast, LAOA exhibited no change in foot clearance with Plain décor. Patterned décor slowed descent (Busy: p < .001, gav = 0.2), increased margins of stability (Busy: p < .001, gav = 0.41; Striped: p < .001, gav = 0.25) and reduced steps looked ahead (Busy: p = .053, gav = 0.25; Striped: p = .039, gav = 0.28) in all ages and abilities. This reflects cautious descent, likely due to more challenging conditions for visually extracting information about the spatial characteristics of the steps useful to guide descent. Edge highlighters: Step-edge highlighters increased confidence (p < .001, gav = 0.53) and reduced anxiety (p < .001, gav = 0.45) in all ages and abilities and for all décor, whilst removing them slowed descent in HAOA (p = .01, gav = 0.26) and LAOA (p = .003, gav = 0.25). Step-edge highlighters also increased foot clearance in YA and HAOA (p = .003, gav = 0.14), whilst LAOA older adults showed no adaptation. No change in foot clearances with décor or step-edge highlighters in LAOA suggests an inability to adapt to step-surface visual properties. CONCLUSION Patterned step surfaces can lead to more cautious and demanding stair negotiation from the perspective of visually extracting spatial information about the steps. In contrast, plain décor with step edge highlighters improves safety. We therefore suggest plain décor with edge highlighters is preferable for use on stairs.
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Affiliation(s)
- Neil M Thomas
- Research to Improve Stair Climbing Safety (RISCS), Faculty of Science, School of Sport and Exercise Sciences, Liverpool John Moores University, Byrom Street, Liverpool, L3 3AF, United Kingdom.
| | - Timmion K Skervin
- Research to Improve Stair Climbing Safety (RISCS), Faculty of Science, School of Sport and Exercise Sciences, Liverpool John Moores University, Byrom Street, Liverpool, L3 3AF, United Kingdom
| | - Richard J Foster
- Research to Improve Stair Climbing Safety (RISCS), Faculty of Science, School of Sport and Exercise Sciences, Liverpool John Moores University, Byrom Street, Liverpool, L3 3AF, United Kingdom
| | - Johnny V Parr
- Research Centre for Musculoskeletal Science and Sports Medicine, Department of Sport and Exercise Sciences, Manchester Metropolitan University, Manchester, United Kingdom
| | - Mark G Carpenter
- School of Kinesiology, The University of British Columbia, University Blvd, V6T 1Z3, Canada
| | - Thomas D O'Brien
- Research to Improve Stair Climbing Safety (RISCS), Faculty of Science, School of Sport and Exercise Sciences, Liverpool John Moores University, Byrom Street, Liverpool, L3 3AF, United Kingdom
| | - Constantinos N Maganaris
- Research to Improve Stair Climbing Safety (RISCS), Faculty of Science, School of Sport and Exercise Sciences, Liverpool John Moores University, Byrom Street, Liverpool, L3 3AF, United Kingdom
| | - Vasilios Baltzopoulos
- Research to Improve Stair Climbing Safety (RISCS), Faculty of Science, School of Sport and Exercise Sciences, Liverpool John Moores University, Byrom Street, Liverpool, L3 3AF, United Kingdom
| | - Carolyn Lees
- Faculty of Education, Health and Community, School of Nursing and Allied Health, Liverpool John Moores University, Byrom Street, Liverpool, L3 3AF, United Kingdom
| | - Mark A Hollands
- Research to Improve Stair Climbing Safety (RISCS), Faculty of Science, School of Sport and Exercise Sciences, Liverpool John Moores University, Byrom Street, Liverpool, L3 3AF, United Kingdom
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14
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Zaback M, Luu MJ, Adkin AL, Carpenter MG. Selective preservation of changes to standing balance control despite psychological and autonomic habituation to a postural threat. Sci Rep 2021; 11:384. [PMID: 33431937 PMCID: PMC7801693 DOI: 10.1038/s41598-020-79417-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Accepted: 11/30/2020] [Indexed: 01/29/2023] Open
Abstract
Humans exhibit changes in postural control when confronted with threats to stability. This study used a prolonged threat exposure protocol to manipulate emotional state within a threatening context to determine if any threat-induced standing behaviours are employed independent of emotional state. Retention of balance adaptations was also explored. Thirty-seven adults completed a series of 90-s standing trials at two surface heights (LOW: 0.8 m above ground, away from edge; HIGH: 3.2 m above ground, at edge) on two visits 2-4 weeks apart. Psychological and autonomic state was assessed using self-report and electrodermal measures. Balance control was assessed using centre of pressure (COP) and lower limb electromyographic recordings. Upon initial threat exposure, individuals leaned backward, reduced low-frequency centre of pressure (COP) power, and increased high-frequency COP power and plantar/dorsiflexor coactivation. Following repeated exposure, the psychological and autonomic response to threat was substantially reduced, yet only high-frequency COP power and plantar/dorsiflexor coactivation habituated. Upon re-exposure after 2-4 weeks, there was partial recovery of the emotional response to threat and few standing balance adaptations were retained. This study suggests that some threat-induced standing behaviours are coupled with the psychological and autonomic state changes induced by threat, while others may reflect context-appropriate adaptations resistant to habituation.
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Affiliation(s)
- Martin Zaback
- grid.17091.3e0000 0001 2288 9830School of Kinesiology, University of British Columbia, 6108 Thunderbird Blvd., Vancouver, BC V6T 1Z4 Canada
| | - Minh John Luu
- grid.17091.3e0000 0001 2288 9830School of Kinesiology, University of British Columbia, 6108 Thunderbird Blvd., Vancouver, BC V6T 1Z4 Canada
| | - Allan L. Adkin
- grid.411793.90000 0004 1936 9318Department of Kinesiology, Brock University, St. Catharines, ON Canada
| | - Mark G. Carpenter
- grid.17091.3e0000 0001 2288 9830School of Kinesiology, University of British Columbia, 6108 Thunderbird Blvd., Vancouver, BC V6T 1Z4 Canada ,grid.17091.3e0000 0001 2288 9830Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC Canada ,grid.17091.3e0000 0001 2288 9830International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, BC Canada
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The effects of perturbation type and direction on threat-related changes in anticipatory postural control. Hum Mov Sci 2020; 73:102674. [PMID: 32829121 DOI: 10.1016/j.humov.2020.102674] [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] [Received: 04/13/2020] [Revised: 07/09/2020] [Accepted: 08/11/2020] [Indexed: 12/19/2022]
Abstract
The purpose of this study was to determine whether the type and direction of postural perturbation threat differentially affect anticipatory postural control. Healthy young adults stood on a force plate fixed to a translating platform and completed a series of rise-to-toes movements without (No Threat) and with (Threat) the potential of receiving a postural perturbation to either their feet (15 participants) or torso (16 participants). Each type of perturbation threat was presented along the anteroposterior (A-P) or mediolateral (M-L) axis. For each condition, the A-P center of pressure (COP) signal and tibialis anterior (TA) and soleus (SOL) electromyographical (EMG) recordings were used to quantify the anticipatory postural adjustment (APA). Results indicated that across both threat types and directions, postural threat induced a 40.2% greater TA activation (p < 0.001), a 18.5% greater backward COP displacement (p < 0.001) and a 23.9% greater backward COP velocity (p < 0.001), leading to larger and faster APAs than the No Threat condition. Subsequently, a 7.7% larger forward COP displacement (p = 0.001), a 20.4% greater forward COP velocity (p < 0.001) and 43.2% greater SOL activation (p = 0.009) were observed during the execution phase of the rise-to-toes for the Threat compared to the No Threat condition. Despite these threat effects, there were no differences in the magnitude or velocity of APAs between the threat directsion conditions. Since the type and direction of perturbation-induced postural threat had minimal differential effects on anticipatory postural control, these factors are unlikely to explain the discrepancy of previous findings.
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16
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Effects of state anxiety on gait: a 7.5% carbon dioxide challenge study. PSYCHOLOGICAL RESEARCH 2020; 85:2444-2452. [PMID: 32737585 PMCID: PMC8357656 DOI: 10.1007/s00426-020-01393-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Accepted: 07/14/2020] [Indexed: 11/20/2022]
Abstract
We used the 7.5% carbon dioxide (CO2) model of anxiety induction to investigate the effects of state anxiety on normal gait and gait when navigating an obstacle. Healthy volunteers (n = 22) completed a walking task during inhalations of 7.5% CO2 and medical air (placebo) in a within-subjects design. The order of inhalation was counterbalanced across participants and the gas was administered double-blind. Over a series of trials, participants walked the length of the laboratory, with each trial requiring participants to navigate through an aperture (width adjusted to participant size), with gait parameters measured via a motion capture system. The main findings were that walking speed was slower, but the adjustment in body orientation was greater, during 7.5% CO2 inhalation compared to air. These findings indicate changes in locomotor behaviour during heightened state anxiety that may reflect greater caution when moving in an agitated state. Advances in sensing technology offer the opportunity to monitor locomotor behaviour, and these findings suggest that in doing so, we may be able to infer emotional states from movement in naturalistic settings.
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17
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Control of landing under conditions of height-induced threat. Eur J Appl Physiol 2020; 120:1827-1839. [DOI: 10.1007/s00421-020-04413-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Accepted: 06/01/2020] [Indexed: 11/27/2022]
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18
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Ellmers TJ, Maslivec A, Young WR. Fear of Falling Alters Anticipatory Postural Control during Cued Gait Initiation. Neuroscience 2020; 438:41-49. [PMID: 32407974 DOI: 10.1016/j.neuroscience.2020.04.050] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2019] [Revised: 04/29/2020] [Accepted: 04/30/2020] [Indexed: 10/24/2022]
Abstract
Fear of falling can have a profound influence on anticipatory postural control during dynamic balance tasks (e.g., rise-to-toes and leg-raise tasks), with fearful individuals typically exhibiting postural adjustments of smaller magnitudes prior to movement onset. However, very little is known about how fear of falling influences the generation of anticipatory postural adjustments (APAs) during gait initiation; a task in which producing smaller APAs may compromise stability. Sixteen young adults initiated gait as fast as possible following an auditory cue during two conditions: Baseline (ground level), and Threat (fear of falling induced via a platform raised 1.1 m). While the magnitude and duration of APAs did not change between conditions, participants executed steps of shorter lengths during Threat. As APAs during gait initiation are typically proportionate to the length of the first step, the APAs during Threat are therefore disproportionately large (given the shorter step length). We suggest that such failure to scale the APA to the magnitude of the motor output represents a fear-related 'overcompensation', whereby fearful participants sought to ensure that the APA was sufficient for ensuring that their centre of mass was positioned above the support leg prior to gait initiation. During conditions of threat, participants also exhibited greater postural sway prior to initiating gait (i.e., following the auditory cue) and took longer to generate the APA (i.e., impaired reaction). As greater reaction times during voluntary stepping is consistently associated with increased fall-risk, we suggest this as one mechanism through which fear of falling may reduce balance safety.
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Affiliation(s)
- Toby J Ellmers
- College of Health and Life Sciences, Brunel University London, UK; The Centre for Cognitive Neuroscience, Brunel University London, UK.
| | - Amy Maslivec
- Department of Surgery & Cancer, Faculty of Medicine, Imperial College London, UK
| | - William R Young
- School of Sport and Health Sciences, University of Exeter, UK; College of Health and Life Sciences, Brunel University London, UK
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19
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Thomas NM, Skervin T, Foster RJ, O'Brien TD, Carpenter MG, Maganaris CN, Baltzopoulos V, Lees C, Hollands MA. Optimal lighting levels for stair safety: Influence of lightbulb type and brightness on confidence, dynamic balance and stepping characteristics. Exp Gerontol 2020; 132:110839. [PMID: 31958491 DOI: 10.1016/j.exger.2020.110839] [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] [Received: 09/16/2019] [Revised: 12/11/2019] [Accepted: 01/10/2020] [Indexed: 11/28/2022]
Abstract
INTRODUCTION Poor lighting has been associated with stair falls in young and older adults. However, current guidelines for illuminating stairs seem arbitrary, differ widely between sources, and are often difficult to interpret. AIMS Here we examined the influence of real-world bulb illumination properties on stair descent safety in young and older adults, with a view to generating preliminary evidence for appropriate lightbulb use/stair illumination. METHODS Stair tread illumination (lx) was measured in a standard UK home (2.23 m ceiling) from a low (50 W; 630 lm) and a high (103 W, 1450 lm) power compact fluorescent lamp (CFL) bulb from the time they were turned on until they reached full brightness. This enabled modelling of their illumination characteristics during warm up. Illumination was also measured from a low (40 W, 470 lm) and a high (100 W, 1521 lm) power LED bulb at first turn-on. Computer-controlled custom lighting then replicated these profiles, in addition to a Bright control (350 lx), on an instrumented staircase descended (3 × trials per light condition) by 12 young (25.3 ± 4.4 years; 5 males), 12 higher ability older (HAOA: 69.6 ± 4.7 years; 5 males) and 13 lower ability older (LAOA: 72.4 ± 4.2; 3 males) healthy adults. Older adults were allocated to ability groups based on physiological and cognitive function. Stair-specific confidence was assessed prior to the first descent in each new lighting condition, and whole-body 3D kinematics (Vicon) quantified margins of stability and foot clearances with respect to the step edges. Mixed ANOVAs examined these measures for within-subject effects of lighting (×5), between-subject effects of age (×3) and interactions between lighting and age. RESULTS Use of CFL bulbs led to lower self-reported confidence in older adults (20.37%, p = .01), and increased margins of stability (12.47%, p = .015) and foot clearances with respect to the step edges (10.36%, p = .003). Importantly, using CFL bulbs increased foot clearance variability with respect to the bottom step (32.74%, p = .046), which is where a high proportion of falls occur. CONCLUSION Stair-tread illumination from CFL bulbs at first turn on leads to less safe stair negotiation. We suggest high powered LED bulbs may offer a safer alternative.
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Affiliation(s)
- Neil M Thomas
- Research to Improve Stair Climbing Safety (RISCS), Faculty of Science, School of Sport and Exercise Sciences, Liverpool John Moores University, Byrom Street, Liverpool L3 3AF, United Kingdom.
| | - Timmion Skervin
- Research to Improve Stair Climbing Safety (RISCS), Faculty of Science, School of Sport and Exercise Sciences, Liverpool John Moores University, Byrom Street, Liverpool L3 3AF, United Kingdom
| | - Richard J Foster
- Research to Improve Stair Climbing Safety (RISCS), Faculty of Science, School of Sport and Exercise Sciences, Liverpool John Moores University, Byrom Street, Liverpool L3 3AF, United Kingdom
| | - Thomas D O'Brien
- Research to Improve Stair Climbing Safety (RISCS), Faculty of Science, School of Sport and Exercise Sciences, Liverpool John Moores University, Byrom Street, Liverpool L3 3AF, United Kingdom
| | - Mark G Carpenter
- School of Kinesiology, The University of British Columbia, University Blvd, V6T 1Z3, Canada
| | - Constantinos N Maganaris
- Research to Improve Stair Climbing Safety (RISCS), Faculty of Science, School of Sport and Exercise Sciences, Liverpool John Moores University, Byrom Street, Liverpool L3 3AF, United Kingdom
| | - Vasilios Baltzopoulos
- Research to Improve Stair Climbing Safety (RISCS), Faculty of Science, School of Sport and Exercise Sciences, Liverpool John Moores University, Byrom Street, Liverpool L3 3AF, United Kingdom
| | - Carolyn Lees
- Faculty of Education, Health and Community, School of Nursing and Allied Health, Liverpool John Moores University, Byrom Street, Liverpool L3 3AF, United Kingdom
| | - Mark A Hollands
- Research to Improve Stair Climbing Safety (RISCS), Faculty of Science, School of Sport and Exercise Sciences, Liverpool John Moores University, Byrom Street, Liverpool L3 3AF, United Kingdom
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20
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The effects of distraction on threat-related changes in standing balance control. Neurosci Lett 2019; 716:134635. [PMID: 31751670 DOI: 10.1016/j.neulet.2019.134635] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Revised: 11/14/2019] [Accepted: 11/17/2019] [Indexed: 01/18/2023]
Abstract
Research indicates that threat-induced changes in standing balance are associated with shifts in attention focus. This study investigated whether distracting attention modifies threat-induced changes in standing balance. Twenty-five healthy young adults stood without (No Threat) and with (Threat) the possibility of receiving a temporally unpredictable anteroposterior support surface translation. In both conditions, participants completed a distractor task that consisted of counting how often a pre-selected letter occurred in an auditory sequence, or no distractor task. Emotional responses to threat were quantified using electrodermal activity and self-report measures, while attention focus was quantified using self-report. Centre of pressure (COP) was measured to assess changes in standing balance. Results indicate that postural threat induced an emotional response, as well as broad shifts in attention focus and changes in standing balance. Distracting attention with a cognitive task mitigated threat-induced increases in medium-frequency COP displacements (0.5-1.8 Hz). These results provide support for a relationship between threat-related changes in balance control and attention focus.
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21
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Zaback M, Adkin AL, Carpenter MG. Adaptation of emotional state and standing balance parameters following repeated exposure to height-induced postural threat. Sci Rep 2019; 9:12449. [PMID: 31462652 PMCID: PMC6713771 DOI: 10.1038/s41598-019-48722-z] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Accepted: 08/07/2019] [Indexed: 11/12/2022] Open
Abstract
Height-induced postural threat influences standing balance control. However, it is unknown if minimizing individuals’ emotional response to threat moderates this relationship. This study repeatedly exposed individuals to height-induced postural threat to determine if reducing the emotional response to threat influences standing balance control. Sixty-eight young adults completed a series of standing trials at LOW (0.8 m above ground, away from edge) and HIGH (3.2 m above ground, at edge) postural threat conditions. Emotional state was assessed using self-report and electrodermal measures. Standing balance was assessed through analysis of centre of pressure (COP) movement and lower leg electromyographic activity. Individuals’ emotional response to threat was attenuated following repeated threat exposure. However, threat-induced changes in standing balance were largely preserved. When initially threatened, individuals leaned backward and demonstrated smaller amplitude and higher frequency of COP adjustments; these balance outcomes did not change following repeated threat exposure. Only high frequency COP oscillations (>1.8 Hz) and ankle muscle co-contraction showed any adaptation; regression analyses showed that these behavioural adaptations were accounted for by a combination of emotional and cognitive state changes. This suggests that some threat-induced standing balance changes are more closely linked with the emotional response to threat than others, and are therefore amendable to intervention.
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Affiliation(s)
- Martin Zaback
- School of Kinesiology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Allan L Adkin
- Department of Kinesiology, Brock University, St. Catharines, Ontario, Canada
| | - Mark G Carpenter
- School of Kinesiology, University of British Columbia, Vancouver, British Columbia, Canada. .,Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, British Columbia, Canada. .,International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, British Columbia, Canada.
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22
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Ellmers TJ, Cocks AJ, Young WR. Exploring attentional focus of older adult fallers during heightened postural threat. PSYCHOLOGICAL RESEARCH 2019; 84:1877-1889. [PMID: 31119367 PMCID: PMC7479009 DOI: 10.1007/s00426-019-01190-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Accepted: 04/17/2019] [Indexed: 11/04/2022]
Abstract
Objectives Threats to balance, and subsequent increases in fall-related anxiety, can disrupt attentional processing during gait in older adults, leading to behavioral adaptations which may increase fall risk. However, limited research has investigated what changes in attention occur to contribute to these disruptions. The aim of this research was to describe changes in attention that occur during gait when older adults’ balance is threatened, while exploring how previous fall history and trait movement reinvestment (conscious monitoring and control of movement) also influence attention. Methods Forty older adults reported where they focus their attention when walking during two scenarios: (1) when they are relaxed and there is little risk of falling, and; (2) when their balance is threatened and they are anxious of falling. Results During the high-threat condition, participants reported greater attention towards movement processes, threats to balance, worries/disturbing thoughts and self-regulatory strategies, with less attention directed towards task-irrelevant thoughts. However, fall history influenced attentional focus, with fallers directing greater attention towards worries/disturbing thoughts. Contrary to predictions, trait movement reinvestment was not associated with attention directed towards movement processes. Discussion As processing worries/disturbing thoughts will likely reduce attentional resources available for effective postural control, we highlight this as one potential area to target interventions aimed at reducing the likelihood of repeated falling. Electronic supplementary material The online version of this article (10.1007/s00426-019-01190-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Toby J Ellmers
- College of Health and Life Sciences, Brunel University London, Uxbridge, UK.
- Institute of Environment, Health and Societies, Brunel University London, Uxbridge, UK.
| | - Adam J Cocks
- College of Health and Life Sciences, Brunel University London, Uxbridge, UK
- Centre for Cognitive Neuroscience, Brunel University London, Uxbridge, UK
| | - William R Young
- College of Health and Life Sciences, Brunel University London, Uxbridge, UK
- Institute of Environment, Health and Societies, Brunel University London, Uxbridge, UK
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23
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The effect of light touch on standing sway when the stability of the external touch reference becomes unreliable. Exp Brain Res 2018; 237:663-672. [DOI: 10.1007/s00221-018-5455-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Accepted: 12/06/2018] [Indexed: 10/27/2022]
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24
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Adkin AL, Carpenter MG. New Insights on Emotional Contributions to Human Postural Control. Front Neurol 2018; 9:789. [PMID: 30298048 PMCID: PMC6160553 DOI: 10.3389/fneur.2018.00789] [Citation(s) in RCA: 72] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Accepted: 08/31/2018] [Indexed: 12/15/2022] Open
Abstract
It has been just over 20 years since the effects of height-induced threat on human postural control were first investigated. Raising the height of the support surface on which individuals stood increased the perceived consequences of instability and generated postural control changes. Since this initial work, converging evidence has accumulated supporting the efficacy of using height-induced threat to study the effects of emotions on postural control and confirming a direct influence of threat-related changes in arousal, anxiety, and fear of falling on all aspects of postural control, including standing, anticipatory, and reactive balance. In general, threat-related postural changes promote a greater physical safety margin while maintaining upright stance. We use the static balance literature to critically examine the current state of knowledge regarding: (1) the extent to which threat-related changes in postural control are sensitive to threat-related changes in emotions; (2) the underlying neurophysiological and cognitive mechanisms that may contribute to explaining the relationship between emotions and postural control; and (3) the generalizability of threat-related changes across different populations and types of threat. These findings have important implications for understanding the neuromechanisms that control healthy balance, and highlight the need to recognize the potential contributions of psychological and physiological factors to balance deficits associated with age or pathology. We conclude with a discussion of the practical significance of this research, its impact on improving diagnosis and treatment of postural control deficits, and potential directions for future research.
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Affiliation(s)
- Allan L Adkin
- 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
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