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Mitsutake T, Sonobe M. Noisy galvanic vestibular stimulation influences head stability in young healthy adults while standing on a moving platform. Gait Posture 2024; 107:177-181. [PMID: 37840004 DOI: 10.1016/j.gaitpost.2023.09.014] [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: 04/02/2023] [Revised: 08/29/2023] [Accepted: 09/26/2023] [Indexed: 10/17/2023]
Abstract
BACKGROUND The ability to stand with eyes closed on a sinusoidal translational moving platform may be affected by spatial orientation owing to vestibular input information. Moreover, changes in the frequency of the moving platform may affect the sensory reweighting through somatosensory and vestibular sensations. However, it is unclear whether noisy galvanic vestibular stimulation (nGVS), which activates vestibular-related brain regions, affects the stability of individuals standing on a platform moving at different frequencies. RESEARCH QUESTION Do vestibular stimulation by nGVS and changes in the frequency of translationally moving platforms affect the standing stability of individuals? METHODS Thirty-one healthy young adult participants were provided both sham and nGVS interventions while they maintained a static standing position, with their eyes closed, on an anterior-posterior sinusoidal translation platform. The nGVS was adapted to an optimal intensity below the perceptual threshold (frequency band: 100-640 Hz), and the sham stimulus was adapted to 0 µA. The participants were randomly assessed for postural stability at 0.2, 0.6, and 1.2 Hz moving platform frequencies for 80 s each under both stimulus conditions. Postural stability was calculated as the root mean square (RMS) sway from head accelerations in the anteroposterior (AP) and mediolateral (ML) directions for 50 s between 20 and 70 s during the 80 s period, measured using an inertial sensor placed on the external occipital ridge. RESULTS nGVS significantly reduced the RMS sway of head acceleration in the AP direction compared with sham stimulation. Furthermore, nGVS significantly reduced RMS sway in the ML direction compared with sham stimulation at a 1.2 Hz moving platform oscillation. SIGNIFICANCE These findings suggest that postural adjustment by the vestibular system influences head stability on a moving platform at specific sinusoidal translation frequencies, suggesting that nGVS may reduce head sway.
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Affiliation(s)
- Tsubasa Mitsutake
- Department of Physical Therapy, Faculty of Medical Science, Fukuoka International University of Health and Welfare, Fukuoka, Japan.
| | - Motomichi Sonobe
- Department of Intelligent Mechanical Systems Engineering, Kochi University of Technology, Kochi, Japan
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Sozzi S, Ghai S, Schieppati M. The 'Postural Rhythm' of the Ground Reaction Force during Upright Stance and Its Conversion to Body Sway-The Effect of Vision, Support Surface and Adaptation to Repeated Trials. Brain Sci 2023; 13:978. [PMID: 37508910 PMCID: PMC10377030 DOI: 10.3390/brainsci13070978] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Revised: 06/12/2023] [Accepted: 06/18/2023] [Indexed: 07/30/2023] Open
Abstract
The ground reaction force (GRF) recorded by a platform when a person stands upright lies at the interface between the neural networks controlling stance and the body sway deduced from centre of pressure (CoP) displacement. It can be decomposed into vertical (VGRF) and horizontal (HGRF) vectors. Few studies have addressed the modulation of the GRFs by the sensory conditions and their relationship with body sway. We reconsidered the features of the GRFs oscillations in healthy young subjects (n = 24) standing for 90 s, with the aim of characterising the possible effects of vision, support surface and adaptation to repeated trials, and the correspondence between HGRF and CoP time-series. We compared the frequency spectra of these variables with eyes open or closed on solid support surface (EOS, ECS) and on foam (EOF, ECF). All stance trials were repeated in a sequence of eight. Conditions were randomised across different days. The oscillations of the VGRF, HGRF and CoP differed between each other, as per the dominant frequency of their spectra (around 4 Hz, 0.8 Hz and <0.4 Hz, respectively) featuring a low-pass filter effect from VGRF to HGRF to CoP. GRF frequencies hardly changed as a function of the experimental conditions, including adaptation. CoP frequencies diminished to <0.2 Hz when vision was available on hard support surface. Amplitudes of both GRFs and CoP oscillations decreased in the order ECF > EOF > ECS ≈ EOS. Adaptation had no effect except in ECF condition. Specific rhythms of the GRFs do not transfer to the CoP frequency, whereas the magnitude of the forces acting on the ground ultimately determines body sway. The discrepancies in the time-series of the HGRF and CoP oscillations confirm that the body's oscillation mode cannot be dictated by the inverted pendulum model in any experimental conditions. The findings emphasise the robustness of the VGRF "postural rhythm" and its correspondence with the cortical theta rhythm, shed new insight on current principles of balance control and on understanding of upright stance in healthy and elderly people as well as on injury prevention and rehabilitation.
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Affiliation(s)
| | - Shashank Ghai
- Department of Political, Historical, Religious and Cultural Studies, Karlstad University, 65188 Karlstad, Sweden
- Centre for Societal Risk Research, Karlstad University, 65188 Karlstad, Sweden
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Bendixen JB, Biddinger BT, Simon JE, Monfort SM, Grooms DR. Effects of virtual reality immersion on postural stability during a dynamic transition task. Sports Biomech 2023:1-15. [PMID: 36597788 PMCID: PMC10847845 DOI: 10.1080/14763141.2022.2162434] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Accepted: 12/20/2022] [Indexed: 01/05/2023]
Abstract
Dynamic postural stability paradigms with virtual reality (VR) provide a means to simulate real-world postural challenges and induce customised but controlled perturbations. The purpose of this study was to determine the effects of a VR unanticipated perceptual sport perturbation on postural stability compared to traditional methods. Sixteen individuals between the ages of 18-23 years (19.5 ± 1.4 years) with no history of injury within 12 months were recruited. A double-leg to single-leg transition task was performed on a force plate in one of the following conditions: eyes open (EO), eyes closed (EC), a sport video with a standard non-immersive computer monitor (SV), and VR. The VR and SV conditions used a pre-recorded tackle avoidance task video where participants shifted to a leg in the opposite direction of a simulated opponent, while EC and EO were completed with auditory prompts. Relative to the EO condition, EC and VR induced greater postural instability. The largest effect sizes were between VR and EO for path length (g = 3.57), mean velocity anterior-posterior centre of pressure (CoP) (g = 3.65), and mean velocity medial-lateral CoP (g = 3.27). By including VR, the difficulty of a clinically based postural stability task was increased to the level of EC while accounting for the sporting environment.
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Affiliation(s)
- Jake B. Bendixen
- School of Applied Health Sciences and Wellness, College of Health Sciences and Professions, Ohio University, Athens, OH, USA
| | - Ben T. Biddinger
- School of Applied Health Sciences and Wellness, College of Health Sciences and Professions, Ohio University, Athens, OH, USA
| | - Janet E. Simon
- School of Applied Health Sciences and Wellness, College of Health Sciences and Professions, Ohio University, Athens, OH, USA
- Ohio Musculoskeletal and Neurological Institute, Ohio University, Athens, OH, USA
| | - Scott M. Monfort
- Department of Mechanical and Industrial Engineering, Montana State University, Bozeman, MT, USA
| | - Dustin R. Grooms
- School of Applied Health Sciences and Wellness, College of Health Sciences and Professions, Ohio University, Athens, OH, USA
- Ohio Musculoskeletal and Neurological Institute, Ohio University, Athens, OH, USA
- School of Rehabilitation and Communications Science, College of Health Sciences and Professions, Ohio University, Athens, OH, USA
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4
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Taleshi N, Brownjohn JMW, Lamb SE, Zivanovic S, Williams GKR. Vector coding reveals the underlying balance control strategies used by humans during translational perturbation. Sci Rep 2022; 12:21030. [PMID: 36470936 PMCID: PMC9722668 DOI: 10.1038/s41598-022-24731-3] [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: 08/23/2022] [Accepted: 11/18/2022] [Indexed: 12/12/2022] Open
Abstract
Postural control research has focused on standing balance experiments on platforms moving with relatively large amplitudes (0.1-0.2 m). This study investigated balance strategies while standing on a platform moving 4 mm in anterior-posterior direction with frequency scaled linearly from 0.4 to 6 Hz. Platform motion and kinematic and kinetic information for nine healthy participants were recorded using motion capture and force plate systems. Coordination between hip, knee and ankle joint torque, and centre of mass (COM) and centre of pressure (COP) motion was quantified by vector coding. Significant main effect of platform frequency for knee-ankle and COP-COM phase relationship was observed (p = 0.023, p = 0.016). At frequencies below 2.11 and 2.34 Hz, ankle strategy was recruited. With ankle strategy, in-phase COP-COM motion with COP dominancy occurred at frequencies below 2.19 and 2.23 Hz during scaling up and down, respectively. As platform frequency passed these values, COM dominated over COP which was followed by anti-phase knee-ankle torque, called a knee strategy, and anti-phase motion between the COP and COM that allowed COP to regain dominance over COM. Collectively, we reveal knee strategy as a new and relevant strategy in real-life settings, and transition between ankle and knee strategies that underpinned transition between COP-COM relative motion.
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Affiliation(s)
- Naser Taleshi
- grid.8391.30000 0004 1936 8024Public Health and Sports Sciences Department, University of Exeter Medical School, Exeter, EX1 2LU UK
| | - James M. W. Brownjohn
- grid.8391.30000 0004 1936 8024Vibration Engineering Section, College of Engineering, Mathematics and Physical Sciences, University of Exeter, Exeter, EX4 4QF UK
| | - Sarah E. Lamb
- grid.8391.30000 0004 1936 8024Public Health and Sports Sciences Department, University of Exeter Medical School, Exeter, EX1 2LU UK
| | - Stana Zivanovic
- grid.8391.30000 0004 1936 8024Vibration Engineering Section, College of Engineering, Mathematics and Physical Sciences, University of Exeter, Exeter, EX4 4QF UK
| | - Genevieve K. R. Williams
- grid.8391.30000 0004 1936 8024Public Health and Sports Sciences Department, University of Exeter Medical School, Exeter, EX1 2LU UK
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5
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Pryhoda M, Newell KM, Wilson C, Irwin G. Task Specific and General Patterns of Joint Motion Variability in Upright- and Hand-Standing Postures. ENTROPY 2022; 24:e24070909. [PMID: 35885134 PMCID: PMC9323647 DOI: 10.3390/e24070909] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Revised: 06/05/2022] [Accepted: 06/23/2022] [Indexed: 12/17/2022]
Abstract
The preservation of static balance in both upright- and hand-stance is maintained by the projection of center of mass (CM) motion within the region of stability at the respective base of support. This study investigated, from a degrees of freedom (DF) perspective, whether the stability of the CM in both upright- and hand-stances was predicted by the respective dispersion and time-dependent regularity of joint (upright stance—ankle, knee, hip, shoulder, neck; hand stance—wrist, elbow, shoulder, neck) angle and position. Full body three-dimensional (3D) kinematic data were collected on 10 advanced level junior female gymnasts during 30 s floor upright- and hand-stands. For both stances the amount of the dispersion of joint angle and sway motion was higher than that of the CM and center of pressure (CP) with an inverse relation to time-dependent irregularity (SampEn). In upright-standing the variability of neck motion in the anterior–posterior direction was significantly greater than that of most joints consistent with the role of vision in the control of quiet upright posture. The findings support the proposition that there are both task specific and general properties to the global CM control strategy in the balance of upright- and hand-standing induced by the different active skeletal-muscular organization and the degeneracy revealed in the multiple distributional variability patterns of the joint angle and position in 3D.
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Affiliation(s)
- Moira Pryhoda
- Department of Mechanical and Materials Engineering, University of Denver, Denver, CO 80208, USA
| | - Karl M Newell
- Department of Kinesiology, University of Georgia, Athens, GA 30602, USA
| | - Cassie Wilson
- Department for Health, University of Bath, Bath BA2 7AY, UK
| | - Gareth Irwin
- Cardiff School of Sport and Health Science, Cardiff Metropolitan University, Cardiff CF23 6XD, UK
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Irwin G, Williams GKR, Kerwin DG, von Lieres Und Wilkau H, Newell KM. Learning the High Bar Longswing:I. Task Dynamics and Emergence of the Coordination Pattern. J Sports Sci 2021; 39:2683-2697. [PMID: 34308780 DOI: 10.1080/02640414.2021.1953828] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
We studied novice gymnasts (N = 25) learning to form the longswing movement coordination pattern. The focus was the emerging behavioural organisation of centre of mass (CM) dynamics and the relative phase of the bar-CM angular motion. Seven novices learned a complete longswing by the end of the study, 8 novices showed no improvement in proportion of circle completed, and the remainder produced modest but persistent increments of final swing height without achieving a full circle. The radial angular velocity generated in the free fall phase and the circle location of bar-CM relative phase progressively and predominantly predicted circle completion. Bar-CM relative phase produced a consistent qualitative relation within- and between-subjects characteristic of a collective variable with the bar leading the CM on the initial downward antiphase segment and the CM leading on the upward antiphase segment. The ratio of these phases was related by the last practice session to degree of circle completion. The findings showed strong individual differences in the effect of practice on the early steps of learning the movement coordination where the progressive emergence of the longswing circle is driven by exploiting the positive- and minimising the negative-influence of gravity on the bar-CM coordination dynamics (candidate collective variable).
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Affiliation(s)
- Gareth Irwin
- Cardiff School of Sport and Health Sciences, Cardiff Metropolitan University, Cardiff, UK
| | | | - David G Kerwin
- Cardiff School of Sport and Health Sciences, Cardiff Metropolitan University, Cardiff, UK
| | | | - Karl M Newell
- Department of Kinesiology, University of Georgia, Athens, USA
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7
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Bidirectional causal control in the dynamics of handstand balance. Sci Rep 2021; 11:405. [PMID: 33432011 PMCID: PMC7801474 DOI: 10.1038/s41598-020-79730-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Accepted: 12/02/2020] [Indexed: 11/25/2022] Open
Abstract
The aim of this study was to identify motor control solutions associated with the ability to maintain handstand balance. Using a novel approach, we investigated the dynamical interactions between centre of pressure (CoP) and centre of mass (CoM) motion. A gymnastics cohort was divided into a ‘less skilled’ group, who held handstands for 4–6 s, and a ‘more skilled’ group, who held handstands in excess of 10 s. CoP–CoM causality was investigated in anterior–posterior (AP) and medio-lateral (ML) directions, in addition to time–space, time–frequency and Hurst Exponent (H) analyses. Lower AP CoP to CoM causal drive and lower H values (> 0.6) indicated the more skilled gymnasts were less reliant on CoP mechanics to drive CoM motion. More skilled performance demonstrated greater adaptability through use of reactive, as opposed to anticipatory, control strategies. Skilled performers additionally exploited mechanical advantages in ML (e.g. a wider base of support), compared to the less skilled athletes. A multiple regression analysis revealed H and frequency domain measures to be better predictors of handstand balance duration than time–space domain measures. The study findings highlight the advantage of an adaptable motor control system with a directional profile, and provide new insight into the clear, measurable footprint of CoP on the dynamics of CoM.
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8
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Newell KM, Liu YT. Collective Variables and Task Constraints in Movement Coordination, Control and Skill. J Mot Behav 2020; 53:770-796. [PMID: 33103621 DOI: 10.1080/00222895.2020.1835799] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
In this paper we review studies that have identified collective variables (order parameters) in movement coordination, control and skill with emphasis on whole-body multiple joint degree of freedom (DF) tasks. Collective variables of a dynamical system have been proposed formally and informally from a diverse set of perceptual-motor tasks, from which we emphasize: bimanual coordination, locomotion (pedalo, walking, running, bicycle riding), roller ball task, static (quiet standing) and dynamic (moving on a ski-simulator) balance, grasping, and juggling. Several types of candidate collective variables have been identified, including: relative phase, frequency ratio, number of hands active in grasping, synchrony, learning rate and relative timing. There is a strong influence of the task goal in determining the collective variable that can be body or environment relative. The emergence of the task relevant collective variable is typically in the early stage of skill learning where subjects through practice adapt movement organization to realize a never previously produced movement coordination pattern. Throughout, the paper elaborates on open theoretical, experimental and analysis issues for collective variables in the context of task constraints and Bernstein's (1967) view of skill acquisition as learning to master redundant DF.
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Affiliation(s)
- Karl M Newell
- Department of Kinesiology, University of Georgia, Athens, Georgia, USA
| | - Yeou-Teh Liu
- Department of Athletic Performance, National Taiwan Normal University, Taipei 116, Taiwan
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9
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Palmer HA, Newell KM, Mulloy F, Gordon D, Smith L, Williams GKR. Movement form of the overarm throw for children at 6, 10 and 14 years of age. Eur J Sport Sci 2020; 21:1254-1262. [PMID: 33028155 DOI: 10.1080/17461391.2020.1834622] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
This study investigated overarm throwing technique at different developmental ages in children from the perspective of three distinct, though potentially complementary, approaches to motor skill acquisition. Children at 6, 10, and 14 years of age (N = 18), completed dominant overarm throws during which whole-body kinematic data were collected. Firstly, application of Newell's ([1985]. Coordination, control and skill. In Advances in Psychology (Vol. 27, pp. 295-317). North-Holland.) stages of learning identified three distinct age-related coupling modes between forward motion of the centre-of-mass (CoM) and the wrist, which demonstrated a greater range of couplings for older children. Secondly, in line with Bernstein's ([1967]. The coordination and regulation of movement. London: Pergamon Press.) hypothesis of freezing before freeing degrees of freedom, a significantly smaller range of motion (ROM) at the ankle and knee joints, but greater ROM at the hip and upper limb joints was found for the 6 year old group compared to the 10 and 14 year old groups. Thirdly, based on the components model (Roberton & Halverson [1984]. Developing children-their changing movement: A guide for teachers. Lea & Febiger.), the overarm throws demonstrated by 6 year olds were characterised as primitive to intermediate, where 10 and 14 year old's throws were characterised by the penultimate action level for each component. Characteristics of CoM-wrist coupling more clearly identify children's age-related technique and highlight the importance of posture-ball release dynamics. The posture-ball dynamics were supported by changes in ROM and the components model, revealing the complementary nature of the three approaches to the analysis of age-related differences in overarm throwing action.
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Affiliation(s)
- Hannah A Palmer
- Cambridge Centre for Sport and Exercise Sciences, Anglia Ruskin University, Cambridge, UK.,School of Computing and Information Science, Anglia Ruskin University, Cambridge, UK
| | - Karl M Newell
- Department of Kinesiology, University of Georgia, Athens, GA, USA
| | - Franky Mulloy
- School of Sport and Exercise Science, University of Lincoln, Lincolnshire, UK
| | - Dan Gordon
- Cambridge Centre for Sport and Exercise Sciences, Anglia Ruskin University, Cambridge, UK
| | - Lee Smith
- Cambridge Centre for Sport and Exercise Sciences, Anglia Ruskin University, Cambridge, UK
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10
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Schut IM, Pasma JH, Veij Mestdagh JCD, Kooij HVD, Schouten AC. Effect of Amplitude and Number of Repetitions of the Perturbation on System Identification of Human Balance Control During Stance. IEEE Trans Neural Syst Rehabil Eng 2019; 27:2336-2343. [PMID: 31545739 DOI: 10.1109/tnsre.2019.2943206] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
To unravel the underlying mechanisms of human balance control, system identification techniques are applied in combination with dedicated perturbations, like support surface translations. However, it remains unclear what the optimal amplitude and number of repetitions of the perturbation signal are. In this study we investigated the effect of the amplitude and number of repetitions on the identification of the neuromuscular controller (NMC). Healthy participants were asked to stand on a treadmill while small continuous support surface translations were applied in the form of a periodic multisine signal. The perturbation amplitude varied over seven conditions between 0.02 and 0.20 m peak-to-peak (ptp), where 6.5 repetitions of the multisine signal were applied for each amplitude, resulting in a trial length of 130 sec. For one of the conditions, 24 repetitions were recorded. The recorded external perturbation torque, body sway and ankle torque were used to calculate both the relative variability of the frequency response function (FRF) of the NMC, i.e., a measure for precision, depending on the noise-to-signal ratio (NSR) and the nonlinear distortions. Results showed that the perturbation amplitude should be minimally 0.05 m ptp, but higher perturbation amplitudes are preferred since they resulted in a higher precision, due to a lower noise-to-signal ratio (NSR). There is, however, no need to further increase the perturbation amplitude than 0.14 m ptp. Increasing the number of repetitions improves the precision, but the number of repetitions minimally required, depends on the perturbation amplitude and the preferred precision. Nonlinear contributions are low and, for the ankle torque, constant over perturbation amplitude.
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11
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Lee IC, Pacheco MM, Newell KM. The precision demands of viewing distance modulate postural coordination and control. Hum Mov Sci 2019; 66:425-439. [PMID: 31174017 DOI: 10.1016/j.humov.2019.05.019] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Revised: 05/24/2019] [Accepted: 05/26/2019] [Indexed: 10/26/2022]
Abstract
There are contrasting views on the role of vision in modifying postural organization (information-driven and postural facilitation) and limited direct tests of the underlying postural mechanisms. Here, we examined whether the distinction between the two views is appropriate given that both are interrelated parts of task constraints modulating postural coordination and control. The study investigated whether changes in the organization of the postural system are a function of the visual precision demands of a task and, in addition, whether such organization could be described as reflecting an intermittent controller. Sixteen participants were instructed to maintain quiet postural stance while fixating a point at different viewing distances (25, 50, 135, 220, 305 cm) or standing with eyes closed. The 25-cm condition showed the lowest standard deviation of the center of pressure (COP) and the highest correlation dimension (CD) in the anterior posterior direction. Analyses revealed that, contrary to the intermittent controller hypothesis, adaptations in the continuous COP and center of mass (COM) coupling characterized the observed changes in CD. The findings show that the natural act of looking to the same feature in the environment as a function of visual viewing distance can lead to quantitative and qualitative changes in the dynamics of posture. This is consistent with the view that postural facilitation and information availability are integrated in the perceptual-motor dynamics.
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Dutt-Mazumder A, Rand TJ, Mukherjee M, Newell KM. Scaling oscillatory platform frequency reveals recurrence of intermittent postural attractor states. Sci Rep 2018; 8:11580. [PMID: 30068921 PMCID: PMC6070516 DOI: 10.1038/s41598-018-29844-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Accepted: 07/16/2018] [Indexed: 12/16/2022] Open
Abstract
The study of postural control has been dominated by experiments on the maintenance of quiet upright standing balance on flat stationary support surfaces that reveal only limited modes of potential configurations of balance stability/instability. Here we examine the self-organization properties of postural coordination as revealed in a dynamic balance task with a moving platform. We scaled a control parameter (platform frequency) to investigate the evolving nature of the coupled oscillator dynamics between center of mass (CoM) and platform. Recurrent map measures were used to reveal whether episodic postural control strategies exist that can be scaled by systematically changing the magnitude of platform motion. The findings showed that at higher platform frequencies (1.2 Hz), the CoM-Platform coupling was less deterministic than lower platform frequencies and evolved to intermittent postural control strategies that oscillated between periodic-chaotic transitions to maintain upright postural balance. Collectively, the recurrence map measures indicated that quasi-static postural attractor states were progressively emerging to the changing task constraints of platform frequency in the maintenance of postural stability. It appears that several dynamic modes of intermittent coupling in postural control can interchangeably co-exist and are expressed as a function of the control parameter of platform frequency.
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Affiliation(s)
- Aviroop Dutt-Mazumder
- Department of Physical Medicine & Rehabilitation, University of Michigan, Ann Arbor, United States.
| | - Troy J Rand
- Department of Biomechanics, University of Nebraska, Omaha, USA
| | - Mukul Mukherjee
- Department of Biomechanics, University of Nebraska, Omaha, USA
| | - Karl M Newell
- Department of Kinesiology, University of Georgia, Athens, USA
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Dutt-Mazumder A, Newell KM. Task experience influences coordinative structures and performance variables in learning a slalom ski-simulator task. Scand J Med Sci Sports 2018; 28:1604-1614. [PMID: 29377312 DOI: 10.1111/sms.13063] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/22/2018] [Indexed: 11/28/2022]
Abstract
The experiment investigated the progressions of the qualitative and quantitative changes in the movement dynamics of learning the ski-simulator as a function of prior-related task experience. The focus was the differential timescales of change in the candidate collective variable, neuromuscular synergies, joint motions, and task outcome as a function of learning over 7 days of practice. Half of the novice participants revealed in day 1 a transition of in-phase to anti-phase coupling of center of mass (CoM)-platform motion whereas the remaining novices and experienced group all produced on the first trial an anti-phase CoM-platform coupling. The experienced group also had initially greater amplitude and velocity of platform motion-a performance advantage over the novice group that was reduced but not eliminated with 7 days of practice. The novice participants who had an in-phase CoM-platform coupling on the initial trials of day 1 also showed the most restricted platform motion in those trials. Prior-related practice experience differentially influenced the learning of the task as evidenced by both the qualitative organization and the quantitative motion properties of the individual degrees of freedom (dof) to meet the task demands. The findings provide further evidence to the proposition that CoM-platform coupling is a candidate collective variable in the ski-simulator task that provides organization and boundary conditions to the motions of the individual joint dof and their couplings.
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Affiliation(s)
- A Dutt-Mazumder
- Department of Radiology, University of Michigan, Ann Arbor, MI, USA
| | - K M Newell
- Department of Kinesiology, University of Georgia, Athens, GA, USA
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Petró B, Papachatzopoulou A, Kiss RM. Devices and tasks involved in the objective assessment of standing dynamic balancing - A systematic literature review. PLoS One 2017; 12:e0185188. [PMID: 28934308 PMCID: PMC5608356 DOI: 10.1371/journal.pone.0185188] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Accepted: 09/07/2017] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Static balancing assessment is often complemented with dynamic balancing tasks. Numerous dynamic balancing assessment methods have been developed in recent decades with their corresponding balancing devices and tasks. OBJECTIVE The aim of this systematic literature review is to identify and categorize existing objective methods of standing dynamic balancing ability assessment with an emphasis on the balancing devices and tasks being used. DATA SOURCES Three major scientific literature databases (Science Direct, Web of Science, PLoS ONE) and additional sources were used. STUDY SELECTION Studies had to use a dynamic balancing device and a task described in detail. Evaluation had to be based on objectively measureable parameters. Functional tests without instrumentation evaluated exclusively by a clinician were excluded. A total of 63 articles were included. DATA EXTRACTION The data extracted during full-text assessment were: author and date; the balancing device with the balancing task and the measured parameters; the health conditions, size, age and sex of participant groups; and follow-up measurements. DATA SYNTHESIS A variety of dynamic balancing assessment devices were identified and categorized as 1) Solid ground, 2) Balance board, 3) Rotating platform, 4) Horizontal translational platform, 5) Treadmill, 6) Computerized Dynamic Posturography, and 7) Other devices. The group discrimination ability of the methods was explored and the conclusions of the studies were briefly summarized. LIMITATIONS Due to the wide scope of this search, it provides an overview of balancing devices and do not represent the state-of-the-art of any single method. CONCLUSIONS The identified dynamic balancing assessment methods are offered as a catalogue of candidate methods to complement static assessments used in studies involving postural control.
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Affiliation(s)
- Bálint Petró
- Department of Mechatronics, Optics and Mechanical Engineering Informatics, Budapest University of Technology and Economics, Budapest, Hungary
| | | | - Rita M Kiss
- Department of Mechatronics, Optics and Mechanical Engineering Informatics, Budapest University of Technology and Economics, Budapest, Hungary
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15
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Dutt-Mazumder A, Newell K. Transitions of postural coordination as a function of frequency of the moving support platform. Hum Mov Sci 2017; 52:24-35. [PMID: 28103469 DOI: 10.1016/j.humov.2017.01.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Revised: 12/23/2016] [Accepted: 01/05/2017] [Indexed: 10/20/2022]
Abstract
This study was set-up to investigate the multi-segmental organization of human postural control in a dynamic balance task. The focus was on the coupling between the center of mass (CoM) and center of pressure (CoP) as a candidate collective variable that supports maintaining balance on a sinusoidal oscillating platform in the medial-lateral (ML) plane and was continuously scaled up and then down across a frequency range from 0.2Hz to 1.2Hz. The CoM-CoP coordination changed from in-phase to anti-phase and anti-phase to in-phase at a critical frequency (∼0.4Hz to 0.6Hz, respectively) in the scaling up or down of the support surface frequency, showed hysteresis as a function of the direction of frequency change and critical fluctuations at the transition region. There was evidence of head motion independent of CoM motion at the higher platform frequencies and a learning effect on several of the dynamic indices over 2days of practice. The findings are consistent with the hypothesis of CoM-CoP acting as an emergent collective variable that is supported by the faster time scale motions of the joints and their synergies in postural control.
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Affiliation(s)
| | - Karl Newell
- Department of Kinesiology, University of Georgia, United States
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16
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Kilby MC, Molenaar PCM, Slobounov SM, Newell KM. Real-time visual feedback of COM and COP motion properties differentially modifies postural control structures. Exp Brain Res 2016; 235:109-120. [PMID: 27644409 DOI: 10.1007/s00221-016-4769-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Accepted: 08/30/2016] [Indexed: 11/26/2022]
Abstract
The experiment was setup to investigate the control of human quiet standing through the manipulation of augmented visual information feedback of selective properties of the motion of two primary variables in postural control: center of pressure (COP) and center of mass (COM). Five properties of feedback information were contrasted to a no feedback dual-task (watching a movie) control condition to determine the impact of visual real-time feedback on the coordination of the joint motions in postural control in both static and dynamic one-leg standing postures. The feedback information included 2D COP or COM position and macro variables derived from the COP and COM motions, namely virtual time-to-contact (VTC) and the COP-COM coupling. The findings in the static condition showed that the VTC and COP-COM coupling feedback conditions decreased postural motion more than the 2D COP or COM positional information. These variables also induced larger sway amplitudes in the dynamic condition showing a more progressive search strategy in exploring the stability limits. Canonical correlation analysis (CCA) found that COP-COM coupling contributed less than the other feedback variables to the redundancy of the system reflected in the common variance between joint motions and properties of sway motion. The COP-COM coupling had the lowest weighting of the motion properties to redundancy under the feedback conditions but overall the qualitative pattern of the joint motion structures was preserved within the respective static and dynamic balance conditions.
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Affiliation(s)
- Melissa C Kilby
- Department of Kinesiology, The University of Georgia, 330 River Rd, Athens, GA, 30602, USA.
| | - Peter C M Molenaar
- Department of Human Development and Family Studies, The Pennsylvania State University, 315 Health and Human Development East, University Park, PA, 16802, USA
| | - Semyon M Slobounov
- Department of Kinesiology, The Pennsylvania State University, 276 Recreation Building, University Park, PA, 16802, USA
| | - Karl M Newell
- Department of Kinesiology, The University of Georgia, 330 River Rd, Athens, GA, 30602, USA
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17
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Dutt-Mazumder A, Challis J, Newell K. Maintenance of postural stability as a function of tilted base of support. Hum Mov Sci 2016; 48:91-101. [DOI: 10.1016/j.humov.2016.04.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Revised: 04/26/2016] [Accepted: 04/30/2016] [Indexed: 11/30/2022]
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18
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Kilby MC, Slobounov SM, Newell KM. Augmented feedback of COM and COP modulates the regulation of quiet human standing relative to the stability boundary. Gait Posture 2016; 47:18-23. [PMID: 27264397 DOI: 10.1016/j.gaitpost.2016.03.021] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Revised: 03/22/2016] [Accepted: 03/31/2016] [Indexed: 02/02/2023]
Abstract
The experiment manipulated real-time kinematic feedback of the motion of the whole body center of mass (COM) and center of pressure (COP) in anterior-posterior (AP) and medial-lateral (ML) directions to investigate the variables actively controlled in quiet standing of young adults. The feedback reflected the current 2D postural positions within the 2D functional stability boundary that was scaled to 75%, 30% and 12% of its original size. The findings showed that the distance of both COP and COM to the respective stability boundary was greater during the feedback trials compared to a no feedback condition. However, the temporal safety margin of the COP, that is, the virtual time-to-contact (VTC), was higher without feedback. The coupling relation of COP-COM showed stable in-phase synchronization over all of the feedback conditions for frequencies below 1Hz. For higher frequencies (up to 5Hz), there was progressive reduction of COP-COM synchronization and local adaptation under the presence of augmented feedback. The findings show that the augmented feedback of COM and COP motion differentially and adaptively influences spatial and temporal properties of postural motion relative to the stability boundary while preserving the organization of the COM-COP coupling in postural control.
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Affiliation(s)
- Melissa C Kilby
- Department of Kinesiology, The University of Georgia, 330 River Rd, Athens, GA 30602, United States.
| | - Semyon M Slobounov
- Department of Kinesiology, The Pennsylvania State University, 276 Recreation Building, University Park, PA 16802, United States.
| | - Karl M Newell
- Department of Kinesiology, The University of Georgia, 330 River Rd, Athens, GA 30602, United States.
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19
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Ko JH, Wang Z, Challis JH, Newell KM. Compensatory mechanisms of balance to the scaling of arm-swing frequency. J Biomech 2015; 48:3825-9. [DOI: 10.1016/j.jbiomech.2015.09.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Revised: 07/18/2015] [Accepted: 09/14/2015] [Indexed: 11/17/2022]
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