scholarly journals Postural Synergies and Their Development

2005 ◽  
Vol 12 (2-3) ◽  
pp. 119-130 ◽  
Author(s):  
Mark L. Latash ◽  
Vijaya Krishnamoorthy ◽  
John P. Scholz ◽  
Vladimir M. Zatsiorsky
Keyword(s):  
Uncontrolled Manifold ◽  
Motor Tasks ◽  
Performance Variables ◽  
Motor Synergies ◽  
Motor Abundance ◽  
Motor Practice ◽  
Recent Developments ◽  
The Central Nervous System ◽  
Postural Perturbations ◽  
Postural Synergies

The recent developments of a particular approach to analyzing motor synergies based on the principle of motor abundance has allowed a quantitative assessment of multieffector coordination in motor tasks involving anticipatory adjustments to self-triggered postural perturbations and in voluntary posturalsway. This approach, the uncontrolled manifold (UCM) hypothesis, is based on an assumption that the central nervous system organizes covariation of elemental variables to stabilize important performance variables in a task-specific manner. In particular, this approach has been used to demonstrate and to assess the emergence of synergies and their modification with motor practice in typical persons and persons with Down syndrome. The framework of the UCM hypothesis allows the formulation of testable hypotheses with respect to developing postural synergies in typically and atypically developing persons.

scholarly journals Motor synergies research in physical therapy: advantages of the uncontrolled manifold approach

2017 ◽  
Vol 24 (1) ◽  
pp. 2-8 ◽  
Author(s):  
Daniela Virgínia Vaz
Keyword(s):  
Physical Therapy ◽  
Relevant Literature ◽  
Movement Control ◽  
Uncontrolled Manifold ◽  
Clinical Activity ◽  
Learning And Development ◽  
Literature Research ◽  
Performance Variables ◽  
Motor Synergies ◽  
Life Tasks

ABSTRACT Movement is central to physical therapy identity and practice. Advances in the science of movement control, motor learning and development are thus inextricably tied to professional development and clinical activity. This paper aims to describe a prominent approach to motor control with potential to greatly advance the understanding of movement dysfunction: the uncontrolled manifold (UCM). An argument is formulated for incorporating this method of data analysis in rehabilitation research. It is a narrative review of the relevant literature. Research in physical therapy could greatly benefit from investigating synergies with the theory and methods of UCM. Research should seek connections between functioning in daily life tasks and the assembling of synergies to stabilize different performance variables, the UCM variability measures, the synergy strength indexes, and the anticipatory synergy adjustments. Changes in these synergy variables should also be quantified after rehabilitation interventions. UCM can offer one solid science-based approach to inform clinical decisions on whether synergies have to be broken, rebalanced, created, or reinforced in patients with movement dysfunction.

scholarly journals Biomechanics as a window into the neural control of movement

2016 ◽  
Vol 52 (1) ◽  
pp. 7-20 ◽  
Author(s):  
Mark L. Latash
Keyword(s):  
Motor Control ◽  
Neural Control ◽  
Laws Of Nature ◽  
Motor Program ◽  
Uncontrolled Manifold ◽  
Living Systems ◽  
Motor Synergies ◽  
The Central Nervous System ◽  
Definition Of ◽  
Neural Control Of Movement

Abstract Biomechanics and motor control are discussed as parts of a more general science, physics of living systems. Major problems of biomechanics deal with exact definition of variables and their experimental measurement. In motor control, major problems are associated with formulating currently unknown laws of nature specific for movements by biological objects. Mechanics-based hypotheses in motor control, such as those originating from notions of a generalized motor program and internal models, are non-physical. The famous problem of motor redundancy is wrongly formulated; it has to be replaced by the principle of abundance, which does not pose computational problems for the central nervous system. Biomechanical methods play a central role in motor control studies. This is illustrated with studies with the reconstruction of hypothetical control variables and those exploring motor synergies within the framework of the uncontrolled manifold hypothesis. Biomechanics and motor control have to merge into physics of living systems, and the earlier this process starts the better.

Abundant Degrees of Freedom Are Not a Problem

2018 ◽  
Vol 7 (1) ◽  
pp. 64-72 ◽  
Author(s):  
Mark L. Latash
Keyword(s):  
Degrees Of Freedom ◽  
Optimization Methods ◽  
Uncontrolled Manifold ◽  
Motor Tasks ◽  
Uncontrolled Manifold Hypothesis ◽  
Motor Synergies ◽  
External Forces ◽  
Applied Fields ◽  
The Brain ◽  
Additional Constraints

The problem of motor redundancy has been one of the fundamental, albeit elusive, problems in motor control. Traditionally, it has been viewed as a computational problem for the brain, solved with either optimization methods or by introducing additional constraints to motor tasks. This review suggests that the problem was wrongly formulated, and that the abundant degrees of freedom are not to be eliminated but used to ensure dynamic stability of motor performance, which is vital given the unpredictable intrinsic states and external forces. The idea of synergies as mechanisms ensuring action stability is introduced based on the uncontrolled manifold hypothesis and the theory of control with spatial referent coordinates. The importance of controlled stability is illustrated with the phenomena of anticipatory synergy adjustments. This approach is productive for both basic and applied fields as illustrated, in particular, by changes in motor synergies with neurological disorder and exercise.

Neurochemistry of L-Glutamate Transport in the CNS: A Review of Thirty Years of Progress

2001 ◽  
Vol 66 (9) ◽  
pp. 1315-1340 ◽  
Author(s):  
Vladimir J. Balcar ◽  
Akiko Takamoto ◽  
Yukio Yoneda
Keyword(s):  
Molecular Biology ◽  
Glutamate Transport ◽  
Mammalian Brain ◽  
Activity Data ◽  
System A ◽  
Recent Developments ◽  
The Central Nervous System ◽  
Health And Disease ◽  
Disease Analysis

The review highlights the landmark studies leading from the discovery and initial characterization of the Na+-dependent "high affinity" uptake in the mammalian brain to the cloning of individual transporters and the subsequent expansion of the field into the realm of molecular biology. When the data and hypotheses from 1970's are confronted with the recent developments in the field, we can conclude that the suggestions made nearly thirty years ago were essentially correct: the uptake, mediated by an active transport into neurons and glial cells, serves to control the extracellular concentrations of L-glutamate and prevents the neurotoxicity. The modern techniques of molecular biology may have provided additional data on the nature and location of the transporters but the classical neurochemical approach, using structural analogues of glutamate designed as specific inhibitors or substrates for glutamate transport, has been crucial for the investigations of particular roles that glutamate transport might play in health and disease. Analysis of recent structure/activity data presented in this review has yielded a novel insight into the pharmacological characteristics of L-glutamate transport, suggesting existence of additional heterogeneity in the system, beyond that so far discovered by molecular genetics. More compounds that specifically interact with individual glutamate transporters are urgently needed for more detailed investigations of neurochemical characteristics of glutamatergic transport and its integration into the glutamatergic synapses in the central nervous system. A review with 162 references.

scholarly journals Advances toward Curing HIV-1 Infection in Tissue Reservoirs

2019 ◽  
Vol 94 (3) ◽  
Author(s):  
Lisa J. Henderson ◽  
Lauren B. Reoma ◽  
Joseph A. Kovacs ◽  
Avindra Nath
Keyword(s):  
Checkpoint Inhibitors ◽  
Functional Cure ◽  
Viral Transcript ◽  
Curative Therapy ◽  
Gene Therapies ◽  
Recent Developments ◽  
The Central Nervous System ◽  
Effector Response ◽  
Hiv 1 ◽  
Cell Effector

ABSTRACT A disease of more than 39.6 million people worldwide, HIV-1 infection has no curative therapy. To date, one man has achieved a sterile cure, with millions more hoping to avoid the potential pitfalls of lifelong antiretroviral therapy and other HIV-related disorders, including neurocognitive decline. Recent developments in immunotherapies and gene therapies provide renewed hope in advancing efforts toward a sterilizing or functional cure. On the horizon is research concentrated in multiple separate but potentially complementary domains: vaccine research, viral transcript editing, T-cell effector response targeting including checkpoint inhibitors, and gene editing. Here, we review the concept of targeting the HIV-1 tissue reservoirs, with an emphasis on the central nervous system, and describe relevant new work in functional cure research and strategies for HIV-1 eradication.

scholarly journals Equifinality and its violations in a redundant system: multifinger accurate force production

2013 ◽  
Vol 110 (8) ◽  
pp. 1965-1973 ◽  
Author(s):  
Luke Wilhelm ◽  
Vladimir M. Zatsiorsky ◽  
Mark L. Latash
Keyword(s):  
Force Production ◽  
Uncontrolled Manifold ◽  
Total Force ◽  
Redundant System ◽  
Uncontrolled Manifold Hypothesis ◽  
Final State ◽  
Performance Variables ◽  
Force Mode ◽  
Finger Forces ◽  
The Individual

We explored a hypothesis that transient perturbations applied to a redundant system result in equifinality in the space of task-related performance variables but not in the space of elemental variables. The subjects pressed with four fingers and produced an accurate constant total force level. The “inverse piano” device was used to lift and lower one of the fingers smoothly. The subjects were instructed “not to intervene voluntarily” with possible force changes. Analysis was performed in spaces of finger forces and finger modes (hypothetical neural commands to fingers) as elemental variables. Lifting a finger led to an increase in its force and a decrease in the forces of the other three fingers; the total force increased. Lowering the finger back led to a drop in the force of the perturbed finger. At the final state, the sum of the variances of finger forces/modes computed across repetitive trials was significantly higher than the variance of the total force/mode. Most variance of the individual finger force/mode changes between the preperturbation and postperturbation states was compatible with constant total force. We conclude that a transient perturbation applied to a redundant system leads to relatively small variance in the task-related performance variable (equifinality), whereas in the space of elemental variables much more variance occurs that does not lead to total force changes. We interpret the results within a general theoretical scheme that incorporates the ideas of hierarchically organized control, control with referent configurations, synergic control, and the uncontrolled manifold hypothesis.

scholarly journals Recent Developments in Microfluidic Technologies for Central Nervous System Targeted Studies

Pharmaceutics ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 542
Author(s):  
Maria Inês Teixeira ◽  
Maria Helena Amaral ◽  
Paulo C. Costa ◽  
Carla M. Lopes ◽  
Dimitrios A. Lamprou
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
State Of The Art ◽  
Physicochemical Characteristics ◽  
Future Perspectives ◽  
Invaluable Tool ◽  
Recent Developments ◽  
The Central Nervous System ◽  
Cns Delivery ◽  
Reproducible Manner

Neurodegenerative diseases (NDs) bear a lot of weight in public health. By studying the properties of the blood-brain barrier (BBB) and its fundamental interactions with the central nervous system (CNS), it is possible to improve the understanding of the pathological mechanisms behind these disorders and create new and better strategies to improve bioavailability and therapeutic efficiency, such as nanocarriers. Microfluidics is an intersectional field with many applications. Microfluidic systems can be an invaluable tool to accurately simulate the BBB microenvironment, as well as develop, in a reproducible manner, drug delivery systems with well-defined physicochemical characteristics. This review provides an overview of the most recent advances on microfluidic devices for CNS-targeted studies. Firstly, the importance of the BBB will be addressed, and different experimental BBB models will be briefly discussed. Subsequently, microfluidic-integrated BBB models (BBB/brain-on-a-chip) are introduced and the state of the art reviewed, with special emphasis on their use to study NDs. Additionally, the microfluidic preparation of nanocarriers and other compounds for CNS delivery has been covered. The last section focuses on current challenges and future perspectives of microfluidic experimentation.

Neuropeptides and anxiety: focus on cholecystokinin

1994 ◽  
Vol 40 (2) ◽  
pp. 315-318 ◽  
Author(s):  
R B Lydiard
Keyword(s):  
Central Nervous System ◽  
Cerebrospinal Fluid ◽  
Potential Role ◽  
Obsessive Compulsive ◽  
Cck Receptors ◽  
Compulsive Disorder ◽  
Therapeutic Uses ◽  
Recent Developments ◽  
The Central Nervous System ◽  
New Compounds

Abstract Cholecystokinin (CCK), a gastrin-like neuropeptide, exists in the central nervous system in several forms. The octapeptide (CCK-8) occurs in predominantly sulfated form (CCK-8S), and the tetrapeptide (CCK-4) occurs in smaller but significant quantities. This review highlights recent developments in preclinical and clinical research into the potential role for CCK in mediating anxiety states. Relevant animal and human studies of administration of CCK agonists are discussed, as well as recent data regarding the concentration of CCK-8S in cerebrospinal fluid from patients with panic disorder, bulimia nervosa, and obsessive compulsive disorder. Finally, the development of agents that specifically antagonize CCK receptors will be described, as will potential therapeutic uses for these new compounds.

Movement Quality: A Novel Biomarker Based on Principles of Neuroscience

2020 ◽  
Vol 34 (12) ◽  
pp. 1067-1077
Author(s):  
Stanislaw Solnik ◽  
Mariusz P. Furmanek ◽  
Daniele Piscitelli
Keyword(s):  
Neurological Disorders ◽  
Motor Behavior ◽  
Group Analysis ◽  
Point Of View ◽  
Uncontrolled Manifold ◽  
Published Data ◽  
Single Individual ◽  
Motor Tasks ◽  
Movement Quality ◽  
Wide Range

A major problem in neurorehabilitation is the lack of objective outcomes to measure movement quality. Movement quality features, such as coordination and stability, are essential for everyday motor actions. These features allow reacting to continuously changing environment or to resist external perturbations. Neurological disorders affect movement quality, leading to functionally impaired movements. Recent findings suggest that the central nervous system organizes motor elements (eg, muscles, joints, fingers) into task-specific ensembles to stabilize motor tasks performance. A method to quantify this feature has been previously developed based on the uncontrolled manifold (UCM) hypothesis. UCM quantifies movement quality in a spatial-temporal domain using intertrial analysis of covariation between motor elements. In this point-of-view article, we first describe major obstacles (eg, the need for group analysis) that interfere with UCM application in clinical settings. Then, we propose a process of quantifying movement quality for a single individual with a novel use of bootstrapping simulations and UCM analysis. Finally, we reanalyze previously published data from individuals with neurological disorders performing a wide range of motor tasks, that is, multi-digit pressing and postural balance tasks. Our method allows one to assess motor quality impairments in a single individual and to detect clinically important motor behavior changes. Our solution may be incorporated into a clinical setting to assess sensorimotor impairments, evaluate the effects of specific neurological treatments, or track movement quality recovery over time. We also recommended the proposed solution to be used jointly with a typical statistical analysis of UCM parameters in cohort studies.

scholarly journals Multidigit force control during unconstrained grasping in response to object perturbations

2017 ◽  
Vol 117 (5) ◽  
pp. 2025-2036 ◽  
Author(s):  
Abdeldjallil Naceri ◽  
Alessandro Moscatelli ◽  
Robert Haschke ◽  
Helge Ritter ◽  
Marco Santello ◽  
...  
Keyword(s):  
Nervous System ◽  
Control Algorithm ◽  
External Disturbance ◽  
Human Hand ◽  
Force Distribution ◽  
Robotic Hand ◽  
Robotic Grasping ◽  
Motor Synergies ◽  
Complex Anatomy ◽  
The Central Nervous System

Because of the complex anatomy of the human hand, in the absence of external constraints, a large number of postures and force combinations can be used to attain a stable grasp. Motor synergies provide a viable strategy to solve this problem of motor redundancy. In this study, we exploited the technical advantages of an innovative sensorized object to study unconstrained hand grasping within the theoretical framework of motor synergies. Participants were required to grasp, lift, and hold the sensorized object. During the holding phase, we repetitively applied external disturbance forces and torques and recorded the spatiotemporal distribution of grip forces produced by each digit. We found that the time to reach the maximum grip force during each perturbation was roughly equal across fingers, consistent with a synchronous, synergistic stiffening across digits. We further evaluated this hypothesis by comparing the force distribution of human grasping vs. robotic grasping, where the control strategy was set by the experimenter. We controlled the global hand stiffness of the robotic hand and found that this control algorithm produced a force pattern qualitatively similar to human grasping performance. Our results suggest that the nervous system uses a default whole hand synergistic control to maintain a stable grasp regardless of the number of digits involved in the task, their position on the objects, and the type and frequency of external perturbations. NEW & NOTEWORTHY We studied hand grasping using a sensorized object allowing unconstrained finger placement. During object perturbation, the time to reach the peak force was roughly equal across fingers, consistently with a synergistic stiffening across fingers. Force distribution of a robotic grasping hand, where the control algorithm is based on global hand stiffness, was qualitatively similar to human grasping. This suggests that the central nervous system uses a default whole hand synergistic control to maintain a stable grasp.

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