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Altenburger P, Ambike SS, Haddad JM. Integrating Motor Variability Evaluation Into Movement System Assessment. Phys Ther 2023; 103:pzad075. [PMID: 37364059 DOI: 10.1093/ptj/pzad075] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Revised: 01/26/2023] [Accepted: 03/19/2023] [Indexed: 06/28/2023]
Abstract
Common assessment tools for determining therapeutic success in rehabilitation typically focus on task-based outcomes. Task-based outcomes provide some understanding of the individual's functional ability and motor recovery; however, these clinical outcomes may have limited translation to a patient's functional ability in the real world. Limitations arise because (1) the focus on task-based outcome assessment often disregards the complexity of motor behavior, including motor variability, and (2) mobility in highly variable real-world environments requires movement adaptability that is made possible by motor variability. This Perspective argues that incorporating motor variability measures that reflect movement adaptability into routine clinical assessment would enable therapists to better evaluate progress toward optimal and safe real-world mobility. The challenges and opportunities associated with incorporating variability-based assessment of pathological movements are also discussed. This Perspective also indicates that the field of rehabilitation needs to leverage technology to advance the understanding of motor variability and its impact on an individual's ability to optimize movement. IMPACT This Perspective contends that traditional therapeutic assessments do not adequately evaluate the ability of individuals to adapt their movements to the challenges faced when negotiating the dynamic environments encountered during daily life. Assessment of motor variability derived during movement execution can address this issue and provide better insight into a patient's movement stability and maneuverability in the real world. Creating such a shift in motor system assessment would advance understanding of rehabilitative approaches to motor system recovery and intervention.
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Affiliation(s)
- Peter Altenburger
- Department of Physical Therapy, School of Health and Human Sciences, Indiana University, Indianapolis, Indiana, USA
| | - Satyajit S Ambike
- Department of Health & Kinesiology, Purdue University, West Lafayette, Indiana, USA
| | - Jeffrey M Haddad
- Department of Health & Kinesiology, Purdue University, West Lafayette, Indiana, USA
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Falaki A, Cuadra C, Lewis MM, Prado-Rico JM, Huang X, Latash ML. Multi-muscle synergies in preparation for gait initiation in Parkinson's disease. Clin Neurophysiol 2023; 154:12-24. [PMID: 37524005 DOI: 10.1016/j.clinph.2023.06.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Revised: 05/20/2023] [Accepted: 06/25/2023] [Indexed: 08/02/2023]
Abstract
OBJECTIVE We investigated changes in indices of muscle synergies prior to gait initiation and the effects of gaze shift in patients with Parkinson's disease (PD). A long-term objective of the study is to develop a method for quantitative assessment of gait-initiation problems in PD. METHODS PD patients without clinical signs of postural instability and two control groups (age-matched and young) performed a gait initiation task in a self-paced manner, with and without a quick prior gaze shift produced by turning the head. Muscle groups with parallel scaling of activation levels (muscle modes) were identified as factors in the muscle activation space. Synergy index stabilizing center of pressure trajectory in the anterior-posterior and medio-lateral directions (indices of stability) was quantified in the muscle mode space. A drop in the synergy index in preparation to gait initiation (anticipatory synergy adjustment, ASA) was quantified. RESULTS Compared to the control groups, PD patients showed significantly smaller synergy indices and ASA for both directions of the center of pressure shift. Both PD and age-matched controls, but not younger controls, showed detrimental effects of the prior gaze shift on the ASA indices. CONCLUSIONS PD patients without clinically significant posture or gait disorders show impaired stability of the center of pressure and its diminished adjustment during gait initiation. SIGNIFICANCE The indices of stability and ASA may be useful to monitor pre-clinical gait disorders, and lower ASA may be relevant to emergence of freezing of gait in PD.
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Affiliation(s)
- Ali Falaki
- Department of Neurosciences, University of Montreal, Montreal, Quebec, Canada
| | - Cristian Cuadra
- Department of Physical Therapy, Emory University, Atlanta, GA, USA; Exercise and Rehabilitation Sciences Laboratory, School of Physical Therapy, Faculty of Rehabilitation Sciences, Universidad Andres Bello, 7591538 Santiago, Chile
| | - Mechelle M Lewis
- Department of Neurology, Milton S. Hershey Medical Center, The Pennsylvania State University, Hershey, PA, USA; Department of Pharmacology, Milton S. Hershey Medical Center, The Pennsylvania State University, Hershey, PA, USA
| | - Janina M Prado-Rico
- Department of Neurology, Milton S. Hershey Medical Center, The Pennsylvania State University, Hershey, PA, USA
| | - Xuemei Huang
- Department of Neurology, Milton S. Hershey Medical Center, The Pennsylvania State University, Hershey, PA, USA; Department of Pharmacology, Milton S. Hershey Medical Center, The Pennsylvania State University, Hershey, PA, USA; Department of Radiology, Milton S. Hershey Medical Center, The Pennsylvania State University, Hershey, PA, USA; Department of Neurosurgery, Milton S. Hershey Medical Center, The Pennsylvania State University, Hershey, PA, USA; Department of Kinesiology, The Pennsylvania State University, University Park, PA, USA
| | - Mark L Latash
- Department of Kinesiology, The Pennsylvania State University, University Park, PA, USA.
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Ghislieri M, Lanotte M, Knaflitz M, Rizzi L, Agostini V. Muscle synergies in Parkinson's disease before and after the deep brain stimulation of the bilateral subthalamic nucleus. Sci Rep 2023; 13:6997. [PMID: 37117317 PMCID: PMC10147693 DOI: 10.1038/s41598-023-34151-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Accepted: 04/25/2023] [Indexed: 04/30/2023] Open
Abstract
The aim of this study is to quantitatively assess motor control changes in Parkinson's disease (PD) patients after bilateral deep brain stimulation of the subthalamic nucleus (STN-DBS), based on a novel muscle synergy evaluation approach. A group of 20 PD patients evaluated at baseline (before surgery, T0), at 3 months (T1), and at 12 months (T2) after STN-DBS surgery, as well as a group of 20 age-matched healthy control subjects, underwent an instrumented gait analysis, including surface electromyography recordings from 12 muscles. A smaller number of muscle synergies was found in PD patients (4 muscle synergies, at each time point) compared to control subjects (5 muscle synergies). The neuromuscular robustness of PD patients-that at T0 was smaller with respect to controls (PD T0: 69.3 ± 2.2% vs. Controls: 77.6 ± 1.8%, p = 0.004)-increased at T1 (75.8 ± 1.8%), becoming not different from that of controls at T2 (77.5 ± 1.9%). The muscle synergies analysis may offer clinicians new knowledge on the neuromuscular structure underlying PD motor types of behavior and how they can improve after electroceutical STN-DBS therapy.
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Affiliation(s)
- Marco Ghislieri
- Department of Electronics and Telecommunications, Politecnico di Torino, 10129, Turin, Italy.
- PolitoBIOMed Lab, Politecnico di Torino, 10129, Turin, Italy.
| | - Michele Lanotte
- Department of Neuroscience "Rita Levi Montalcini", University of Turin, 10126, Turin, Italy
- AOU Città della Salute e della Scienza di Torino, 10126, Turin, Italy
| | - Marco Knaflitz
- Department of Electronics and Telecommunications, Politecnico di Torino, 10129, Turin, Italy
- PolitoBIOMed Lab, Politecnico di Torino, 10129, Turin, Italy
| | - Laura Rizzi
- Department of Neuroscience "Rita Levi Montalcini", University of Turin, 10126, Turin, Italy
- AOU Città della Salute e della Scienza di Torino, 10126, Turin, Italy
| | - Valentina Agostini
- Department of Electronics and Telecommunications, Politecnico di Torino, 10129, Turin, Italy
- PolitoBIOMed Lab, Politecnico di Torino, 10129, Turin, Italy
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Ricotta JM, Nardon M, De SD, Jiang J, Graziani W, Latash ML. Motor unit-based synergies in a non-compartmentalized muscle. Exp Brain Res 2023; 241:1367-1379. [PMID: 37017728 DOI: 10.1007/s00221-023-06606-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Accepted: 03/23/2023] [Indexed: 04/06/2023]
Abstract
The concept of synergies has been used to address the grouping of motor elements contributing to a task with the covariation of these elements reflecting task stability. This concept has recently been extended to groups of motor units with parallel scaling of the firing frequencies with possible contributions of intermittent recruitment (MU-modes) in compartmentalized flexor and extensor muscles of the forearm stabilizing force magnitude in finger pressing tasks. Here, we directly test for the presence and behavior of MU-modes in the tibialis anterior, a non-compartmentalized muscle. Ten participants performed an isometric cyclical dorsiflexion force production task at 1 Hz between 20 and 40% of maximal voluntary contraction and electromyographic (EMG) data were collected from two high-density wireless sensors placed on the skin over the right tibialis anterior. EMG data were decomposed into individual motor unit frequencies and resolved into sets of MU-modes. Inter-cycle analysis of MU-mode magnitudes within the framework of the uncontrolled manifold (UCM) hypothesis was used to quantify force-stabilizing synergies. Two or three MU-modes were identified in all participants and trials accounting, on average, for 69% of variance and were robust to cross-validation measurements. Strong dorsiflexion force-stabilizing synergies in the space of MU-modes were present in all participants and for both electrode locations as reflected in variance within the UCM (median 954, IQR 511-1924) exceeding variance orthogonal to the UCM (median 5.82, IQR 2.9-17.4) by two orders of magnitude. In contrast, MU-mode-stabilizing synergies in the space of motor unit frequencies were not present. This study offers strong evidence for the existence of synergic control mechanisms at the level of motor units independent of muscle compartmentalization, likely organized within spinal cord circuitry.
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Affiliation(s)
- Joseph M Ricotta
- Department of Kinesiology, Rec.Hall-20, The Pennsylvania State University, University Park, PA, 16802, USA.
- Clinical and Translational Science Institute, Penn State College of Medicine, Hershey, PA, 17033, USA.
| | - Mauro Nardon
- Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Sayan D De
- Department of Kinesiology, Rec.Hall-20, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Jinrui Jiang
- Department of Kinesiology, Rec.Hall-20, The Pennsylvania State University, University Park, PA, 16802, USA
| | - William Graziani
- Department of Kinesiology, Rec.Hall-20, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Mark L Latash
- Department of Kinesiology, Rec.Hall-20, The Pennsylvania State University, University Park, PA, 16802, USA
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Song J, Kim K, Park J. Multi-muscle Synergies of Postural Control in Self- and External-Triggered Force Release During Simulated Archery Shooting. J Mot Behav 2023; 55:289-301. [PMID: 36919981 DOI: 10.1080/00222895.2023.2187336] [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: 03/16/2023]
Abstract
We investigated postural stability during simulated archery shooting. The experiment consisted of two force release conditions: self-triggered (time-set in a feedforward fashion) and external cue-triggered (time-set by reacting to external cue) conditions while standing on the force platform. The electromyography of leg muscles and the center of pressure (COP) were recorded. The notions of muscle-modes (M-modes) and multi-muscle synergies were employed to quantify the postural stability, which described covariation patterns of the M-modes to stabilize the COP. The result showed relatively strong postural stability in a self-triggered condition associated with consistent shooting performance. The current findings suggested that initiating force release in a feedforward fashion would be a beneficial strategy to ensure the consistency in shooting performance.
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Affiliation(s)
- Junkyung Song
- Department of Physical Education, Seoul National University, Seoul, South Korea
| | - Kitae Kim
- Korea Institute of Sport Science, Seoul, South Korea
| | - Jaebum Park
- Department of Physical Education, Seoul National University, Seoul, South Korea.,Institute of Sport Science, Seoul National University, Seoul, South Korea.,Advanced Institute of Convergence Science, Seoul National University, Seoul, South Korea.,Department of AI-Integrated Education, Seoul National University, Seoul, South Korea
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de Freitas PB, Freitas SMSF, Prado-Rico JM, Lewis MM, Du G, Yanosky JD, Huang X, Latash ML. Synergic control in asymptomatic welders during multi-finger force exertion and load releasing while standing. Neurotoxicology 2022; 93:324-336. [PMID: 36309163 PMCID: PMC10398836 DOI: 10.1016/j.neuro.2022.10.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Revised: 10/21/2022] [Accepted: 10/22/2022] [Indexed: 11/06/2022]
Abstract
Motor synergies, i.e., neural mechanisms that organize multiple motor elements to ensure stability of actions, are affected by several neurological condition. Asymptomatic welders showed impaired synergy controlling the stability of multi-finger action compared to non-welders and this impairment was associated with microstructural damage in the globus pallidus. We further explored the effect of welding-related metal exposure on multi-finger synergy and extended our investigation to posture-stabilizing synergy during a standing task. Occupational, MRI, and performance-stabilizing synergies during multi-finger accurate force production and load releasing while standing were obtained from 29 welders and 19 age- and sex-matched controls. R2* and R1 relaxation rate values were used to estimate brain iron and manganese content, respectively, and diffusion tensor imaging was used to reflect brain microstructural integrity. Associations of brain MRI (caudate, putamen, globus pallidus, and red nucleus), and motor synergy were explored by group status. The results revealed that welders had higher R2* values in the caudate (p = 0.03), putamen (p = 0.01), and red nucleus (p = 0.08, trend) than controls. No group effect was revealed on multi-finger synergy index during steady-state phase of action (ΔVZss). Compared to controls, welders exhibited lower ΔVZss (-0.106 ± 0.084 vs. 0.160 ± 0.092, p = 0.04) and variance that did not affect the performance variable (VUCM, 0.022 ± 0.003 vs. 0.038 ± 0.007, p = 0.03) in the load releasing, postural task. The postural synergy index, ΔVZss, was associated negatively with higher R2* in the red nucleus in welders (r = -0.44, p = 0.03), but not in controls. These results suggest that the synergy index in the load releasing during a standing task may reflect welding-related neurotoxicity in workers with chronic metals exposure. This finding may have important clinical and occupational health implications.
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Affiliation(s)
- Paulo B de Freitas
- Interdisciplinary Graduate Program in Health Science, Universidade Cruzeiro do Sul, São Paulo, SP, Brazil
| | - Sandra M S F Freitas
- Graduate Program in Physical Therapy, Universidade Cidade de São Paulo, São Paulo, SP, Brazil
| | - Janina M Prado-Rico
- Department of Neurology, Milton S. Hershey Medical Center, The Pennsylvania State University, Hershey, PA, USA
| | - Mechelle M Lewis
- Department of Neurology, Milton S. Hershey Medical Center, The Pennsylvania State University, Hershey, PA, USA; Department of Pharmacology, Milton S. Hershey Medical Center, The Pennsylvania State University, Hershey, PA, USA
| | - Guangwei Du
- Department of Neurology, Milton S. Hershey Medical Center, The Pennsylvania State University, Hershey, PA, USA
| | - Jeff D Yanosky
- Department of Public Health Science, College of Medicine, The Pennsylvania State University, Hershey, PA, USA
| | - Xuemei Huang
- Department of Neurology, Milton S. Hershey Medical Center, The Pennsylvania State University, Hershey, PA, USA; Department of Pharmacology, Milton S. Hershey Medical Center, The Pennsylvania State University, Hershey, PA, USA; Radiology, Milton S. Hershey Medical Center, The Pennsylvania State University, Hershey, PA, USA; Department of Neurosurgery, Milton S. Hershey Medical Center, The Pennsylvania State University, Hershey, PA, USA; Department of Kinesiology, The Pennsylvania State University, University Park, PA, USA.
| | - Mark L Latash
- Department of Kinesiology, The Pennsylvania State University, University Park, PA, USA.
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Synergies Stabilizing Vertical Posture in Spaces of Control Variables. Neuroscience 2022; 500:79-94. [PMID: 35952997 DOI: 10.1016/j.neuroscience.2022.08.006] [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: 05/31/2022] [Revised: 07/14/2022] [Accepted: 08/04/2022] [Indexed: 11/22/2022]
Abstract
In this study, we address the question: Can the central nervous system stabilize vertical posture in the abundant space of neural commands? We assume that the control of vertical posture is associated with setting spatial referent coordinates (RC) for the involved muscle groups, which translates into two basic commands, reciprocal and co-activation. We explored whether the two commands co-varied across trials to stabilize the initial postural state. Young, healthy participants stood quietly against an external horizontal load and were exposed to smooth unloading episodes. Linear regression between horizontal force and center of mass coordinate during the unloading phase was computed to define the intercept (RC) and slope (apparent stiffness, k). Hyperbolic regression between the intercept and slope across unloading episodes and randomization analysis both demonstrated high indexes of co-variation stabilizing horizontal force in the initial state. Higher co-variation indexes were associated with lower average k values across the participants suggesting destabilizing effects of muscle coactivation. Analysis of deviations in the {RC; k} space keeping the posture unchanged (motor equivalent) between two states separated by a voluntary quick body sway showed significantly larger motor equivalent deviations compared to non-motor equivalent ones. This is the first study demonstrating posture-stabilizing synergies in the space of neural control variables using various computational methods. It promises direct applications to studies of postural disorders and rehabilitation.
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Madarshahian S, Latash ML. Effects of hand muscle function and dominance on intra-muscle synergies. Hum Mov Sci 2022; 82:102936. [PMID: 35217391 DOI: 10.1016/j.humov.2022.102936] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Revised: 01/09/2022] [Accepted: 02/13/2022] [Indexed: 11/04/2022]
Abstract
The goal of the study was to explore the effects of hand dominance and muscle function (prime mover vs. supporting muscle) on recently discovered intra-muscle synergies as potential windows into their neural origin. Healthy right-handed subjects performed accurate cyclical force production tasks while pressing with the middle phalanges and distal phalanges of the fingers of the dominant and non-dominant hand. Surface electromyography was used to identify individual motor unit action potentials in two muscles, flexor digitorum superficialis (FDS) and extensor digitorum communis (EDC). Stable motor unit groups (MU-modes) were defined in each muscle and in both muscles together. The composition of the MU-modes allowed linking them to the reciprocal and co-activation command. Force-stabilizing synergies were quantified in each hand and during force production at both sites using the framework of the uncontrolled manifold hypothesis. Force-stabilizing synergies were seen in the spaces of MU-modes from FDS and EDC separately, but not of MU-modes defined for both muscles together. Synergy indices were similar for both hands and both sites of force application. In contrast, force-stabilizing synergies in the space of finger forces were present in the non-dominant hand and absent in the dominant hand. The data suggest existence of distributed mechanisms of synergic control. Finger force synergies are likely to reflect functioning of subcortical loops involving the basal ganglia and cerebellum, while MU-mode synergies are likely to reflect spinal circuitry. Studies of both force-based and motor-unit-based synergies may be clinically valuable for distinguishing effects of spinal and supraspinal disorders.
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Affiliation(s)
- Shirin Madarshahian
- Department of Kinesiology, The Pennsylvania State University, University Park, PA 16802, USA
| | - Mark L Latash
- Department of Kinesiology, The Pennsylvania State University, University Park, PA 16802, USA.
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Latash ML. One more time about motor (and non-motor) synergies. Exp Brain Res 2021; 239:2951-2967. [PMID: 34383080 DOI: 10.1007/s00221-021-06188-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Accepted: 08/03/2021] [Indexed: 11/28/2022]
Abstract
We revisit the concept of synergy based on the recently translated classical book by Nikolai Bernstein (On the construction of movements, Medgiz, Moscow 1947; Latash, Bernstein's Construction of Movements, Routledge, Abingdon 2020b) and progress in understanding the physics and neurophysiology of biological action. Two aspects of synergies are described: organizing elements into stable groups (modes) and ensuring dynamical stability of salient performance variables. The ability of the central nervous system to attenuate synergies in preparation for a quick action-anticipatory synergy adjustments-is emphasized. Recent studies have demonstrated synergies at the level of hypothetical control variables associated with spatial referent coordinates for effectors. Overall, the concept of synergies fits naturally the hierarchical scheme of control with referent coordinates with an important role played by back-coupling loops within the central nervous system and from peripheral sensory endings. Further, we review studies showing non-trivial changes in synergies with development, aging, fatigue, practice, and a variety of neurological disorders. Two aspects of impaired synergic control-impaired stability and impaired agility-are introduced. The recent generalization of the concept of synergies for non-motor domains, including perception, is discussed. We end the review with a list of unresolved and troubling issues.
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Affiliation(s)
- Mark L Latash
- Department of Kinesiology, Rec.Hall-268N, The Pennsylvania State University, University Park, PA, 16802, USA.
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Chen H, Hu Z, Chai Y, Tao E, Chen K, Asakawa T. Galvanic vestibular stimulation with low intensity improves dynamic balance. Transl Neurosci 2021; 12:512-521. [PMID: 34950513 PMCID: PMC8651062 DOI: 10.1515/tnsci-2020-0197] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Revised: 10/20/2021] [Accepted: 11/02/2021] [Indexed: 11/15/2022] Open
Abstract
Background Dynamic balance is associated with fall risk. The aim of this study is to explore the effects of galvanic vestibular stimulation with very low intensity direct current (dcGVS) on dynamic balance. Methodology We used a rocker force platform for assessing the dynamic balance performance. Center-of-pressure (COP) coordinates were acquired and decomposed to rambling (RA) and trembling (TR). We measured sway parameters, including length, average speed, and average range, affected by dcGVS at 0.01 mA with eyes open (EO) and eyes closed (EC). Results We assessed 33 young healthy subjects and found that all sway parameters were shorter in the EO condition, indicating a better dynamic balance performance. dcGVS significantly improved the dynamic balance performance both in EO and EC conditions. All the sway parameters in COP in EO were significantly shorter than those in EC, indicating a better dynamic balance performance in EO. In EO, RA had greater improvement rates than TR. In EC, only average speed had a greater improvement rate in RA, whereas length and average range had greater improvement rates in TR. These results indicate a different modulation model between EO and EC. Conclusion These findings indicate that very low intensity dcGVS improved the sway parameters of dynamic balance in young healthy subjects. Moreover, our results suggest different dynamic balance control models between having EO and EC. The mechanisms of these phenomena caused by very low intensity dcGVS require further investigation.
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Affiliation(s)
- Hongmei Chen
- School of Mechanical Engineering, Hangzhou Dianzi University, No. 1158, Xiasha 2nd Street, Jianggan District, Hangzhou, Zhejiang 310018, China
| | - Zhen Hu
- Department of Neurology, Ruijin Hospital Affiliated to Shanghai Jiao Tong University, Shanghai 200000, China
| | - Yujuan Chai
- School of Medical Engineering, Health Science Center, Shenzhen University, Shenzhen 518060, China
| | - Enxiang Tao
- Department of Neurology, The Eighth Affiliated Hospital, Sun Yat-Sen University, Shenzhen 518033, China
| | - Kai Chen
- School of Mechanical Engineering, Hangzhou Dianzi University, No. 1158, Xiasha 2nd Street, Jianggan District, Hangzhou, Zhejiang 310018, China
| | - Tetsuya Asakawa
- Department of Neurology, The Eighth Affiliated Hospital, Sun Yat-Sen University, Shenzhen 518033, China
- Research Base of Traditional Chinese Medicine Syndrome, Fujian University of Traditional Chinese Medicine, Fuzhou 350122, China
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