scholarly journals An Uncontrolled Manifold Analysis of Arm Joint Variability in Virtual Planar Position and Orientation Telemanipulation

2019 ◽  
Vol 66 (2) ◽  
pp. 391-402 ◽  
Author(s):  
Jacopo Buzzi ◽  
Elena De Momi ◽  
Ilana Nisky

2015 ◽  
Vol 3 ◽  
pp. 1434-1441
Author(s):  
Kostas Gianikellis ◽  
Francisco M. Sánchez-Margallo ◽  
Andreas Skiadopoulos ◽  
Juan A. Sánchez-Margallo ◽  
Javier Hermoso de Mendoza Aranda


Motor Control ◽  
2019 ◽  
Vol 23 (2) ◽  
pp. 189-204 ◽  
Author(s):  
Inge Tuitert ◽  
Tim A. Valk ◽  
Egbert Otten ◽  
Laura Golenia ◽  
Raoul M. Bongers


2004 ◽  
Vol 157 (3) ◽  
Author(s):  
Ning Kang ◽  
Minoru Shinohara ◽  
VladimirM. Zatsiorsky ◽  
MarkL. Latash




2007 ◽  
Vol 183 (4) ◽  
pp. 511-521 ◽  
Author(s):  
David P. Black ◽  
Beth A. Smith ◽  
Jianhua Wu ◽  
Beverly D. Ulrich


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Kyung Koh ◽  
Yang Sun Park ◽  
Da Won Park ◽  
Jae Kun Shim

AbstractProfessional dancers demonstrate an amazing ability to control their balance. However, little is known about how they coordinate their body segments for such superior control. In this study, we investigated how dancers coordinate body segments when a physical perturbation is given to their body. A custom-made machine was used to provide a short pulling impulse at the waist in the anterior direction to ten dancers and ten non-dancers. We used Uncontrolled Manifold analysis to quantify the variability in the task-relevant space and task-irrelevant space within the multi-dimensional space made up of individual segments’ centers of mass with a velocity adjustment. The dancers demonstrated greater utilization of redundant degrees of freedom (DoFs) supported by the greater task-irrelevant variability as compared to non-dancers. These findings suggest that long-term specialized dance training can improve the central nervous system’s ability to utilize the redundant DoFs in the whole-body system.



2021 ◽  
Author(s):  
Hyun Joon Kim ◽  
Joon Ho Lee ◽  
Nyeonju Kang ◽  
James H. Cauraugh

Abstract The purpose of this study was to determine whether altered interlimb coordination patterns across trials improved bimanual force control capabilities within a trial. Fourteen healthy young participants completed bimanual force control tasks at 5%, 25%, and 50% of maximum voluntary contraction with and without visual feedback. To estimate synergetic coordination patterns between hands across multiple trials, we analyzed our primary outcome measure by performing an uncontrolled manifold analysis. In addition, we calculated force accuracy, variability, and regularity within a trial to quantify task stabilization. Using Pearson’s correlation analyses, we determined the relation between the changes in bilateral motor synergies (i.e., a proportion of good variability relative to bad variability) and bimanual force control performance from no-vision to vision conditions. The findings revealed that the presence of visual feedback significantly increased bilateral motor synergies with a reduction of bad variability components across multiple trials, and decreased force error, variability, and regularity within a trial. Further, we observed significant positive correlations between higher bilateral motor synergies and increased improvements in force control capabilities. These findings suggested that bimanual synergetic coordination behaviors at the planning level modulated by external sensory feedback may be related to advanced task stabilization patterns at the execution level.



2018 ◽  
Vol 119 (1) ◽  
pp. 21-32 ◽  
Author(s):  
Mitchell Tillman ◽  
Satyajit Ambike

A motor system configured to maximize the stability of its current state cannot dexterously transition between states. Yet, we routinely resolve the stability-dexterity conflict and rapidly change our current behavior without allowing it to become unstable before the desired transition. The phenomenon called anticipatory synergy adjustment (ASA) partly describes how the central nervous system handles this conflict. ASA is a continuous decrease in the stability of the current motor state beginning 150–400 ms before a rapid state transition accomplished using redundant sets of motor inputs (more input variables than task-specific output variables). So far, ASAs have been observed only when the timing of the upcoming transition is known. We utilized a multifinger, isometric force-production task to demonstrate that compared with a condition where no state transition is expected, the stability of the current state is lower by ~12% when a participant is cued to make a transition, even when the nature and timing of that transition are unknown. This result (stage 1 ASA) is distinct from its traditional version (stage 2 ASA), and it describes early destabilization that occurs solely in response to the expectation to move. Stage 2 ASA occurs later, only if the timing of the transition is known sufficiently in advance. Stage 1 ASA lasts much longer (~1.5 s) and may scale in response to the perceived difficulty of the upcoming task. Therefore, this work reveals a much refined view of the processes that underlie the resolution of the stability-dexterity conflict. NEW & NOTEWORTHY We compared the stability of multifinger, isometric force-production tasks for trials in which force changes of unknown direction and timing were expected with trials in which there was no expectation of any force change. Mere expectation of a change caused the stability of the current motor state to drop. This novel result provides a much refined view of the processes that facilitate dexterous switching between motor states.



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