3D human arm reaching movement planning with principal patterns in successive phases

2020 ◽  
Vol 48 (3) ◽  
pp. 265-280
Author(s):  
Sedigheh Dehghani ◽  
Fariba Bahrami
Keyword(s):  
Movement Planning ◽  
Reaching Movement ◽  
Arm Reaching ◽  
Human Arm

scholarly journals Impaired posture, movement preparation, and execution during both paretic and nonparetic reaching following stroke

2019 ◽  
Vol 121 (4) ◽  
pp. 1465-1477 ◽  
Author(s):  
Chieh-ling Yang ◽  
Robert A. Creath ◽  
Laurence Magder ◽  
Mark W. Rogers ◽  
Sandy McCombe Waller
Keyword(s):  
Postural Control ◽  
Upper Extremity ◽  
Movement Planning ◽  
Clinical Implications ◽  
Healthy Controls ◽  
Movement Preparation ◽  
Movement Response ◽  
Reaching Movement ◽  
Acoustic Stimuli ◽  
Arm Reaching

Posture and movement planning, preparation, and execution of a goal-directed reaching movement are impaired in individuals with stroke. No studies have shown whether the deficits are generally impaired or are specific to the lesioned hemisphere/paretic arm. This study utilized StartReact (SR) responses elicited by loud acoustic stimuli (LAS) to investigate the preparation and execution of anticipatory postural adjustments (APAs) and reach movement response during both paretic and nonparetic arm reaching in individuals with stroke and in age-matched healthy controls. Subjects were asked to get ready after receiving a warning cue and to reach at a “go” cue. An LAS was delivered at –500, –200, and 0 ms relative to the go cue. Kinetic, kinematic, and electromyographic data were recorded to characterize APA-reach movement responses. Individuals with stroke demonstrated systemwide deficits in posture and in movement planning, preparation, and execution of APA-reach sequence as shown by significant reduction in the incidence of SR response and impaired APA-reach performance, with greater deficits during paretic arm reaching. Use of trunk compensation strategy as characterized by greater involvement of trunk and pelvic rotation was utilized by individuals with stroke during paretic arm reaching compared with nonparetic arm reaching and healthy controls. Our findings have implications for upper extremity and postural control, suggesting that intervention should include training not only for the paretic arm but also for the nonparetic arm with simultaneous postural control requirements to improve the coordination of the APA-reach performance and subsequently reduce instability while functional tasks are performed during standing. NEW & NOTEWORTHY Our study is the first to show that nonparetic arm reaching also demonstrates impairment in posture and movement planning, preparation, and execution when performed during standing by individuals with stroke. In addition, we found compensatory trunk and pelvic rotations were used during a standing reach task for the paretic arms. The findings have clinical implications for upper extremity and postural rehabilitation, suggesting that training should include the nonparetic arms and incorporate simultaneous postural control demands.

Optimal trajectory formation of constrained human arm reaching movements

2004 ◽  
Vol 91 (1) ◽  
Author(s):  
Ken Ohta ◽  
Mikhail M. Svinin ◽  
ZhiWei Luo ◽  
Shigeyuki Hosoe ◽  
Rafael Laboissi�re
Keyword(s):  
Optimal Trajectory ◽  
Reaching Movements ◽  
Trajectory Formation ◽  
Arm Reaching ◽  
Human Arm

Hand-held tools with complex kinematics are efficiently incorporated into movement planning and online control

2012 ◽  
Vol 108 (7) ◽  
pp. 1954-1964 ◽  
Author(s):  
Lee A. Baugh ◽  
Erica Hoe ◽  
J. Randall Flanagan
Keyword(s):  
Online Control ◽  
Movement Planning ◽  
Control Mechanisms ◽  
Movement Initiation ◽  
Reaching Movement ◽  
Hand Motion ◽  
Reversal Condition ◽  
End Point ◽  
Point Motion ◽  
Time Required

Certain hand-held tools alter the mapping between hand motion and motion of the tool end point that must be controlled in order to perform a task. For example, when using a pool cue, the motion of the cue tip is reversed relative to the hand. Previous studies have shown that the time required to initiate a reaching movement (Fernandez-Ruiz J, Wong W, Armstrong IT, Flanagan JR. Behav Brain Res 219: 8–14, 2011), or correct an ongoing reaching movement (Gritsenko V, Kalaska JF. J Neurophysiol 104: 3084–3104, 2010), is prolonged when the mapping between hand motion and motion of a cursor controlled by the hand is reversed. Here we show that these time costs can be significantly reduced when the reversal is instantiated by a virtual hand-held tool. Participants grasped the near end of a virtual tool, consisting of a rod connecting two circles, and moved the end point to displayed targets. In the reversal condition, the rod translated through, and rotated about, a pivot point such that there was a left-right reversal between hand and end point motion. In the nonreversal control, the tool translated with the hand. As expected, when only the two circles were presented, movement initiation and correction times were much longer in the reversal condition. However, when full vision of the tool was provided, the reaction time cost was almost eliminated. These results indicate that tools with complex kinematics can be efficiently incorporated into sensorimotor control mechanisms used in movement planning and online control.

Evaluation of Power-Assist System by Computer Simulation

2016 ◽  
Vol 20 (3) ◽  
pp. 477-483 ◽  
Author(s):  
Yoshiaki Taniai ◽  
◽  
Tomohide Naniwa ◽  
Yasutake Takahashi ◽  
Masayuki Kawai
Keyword(s):  
Computer Simulation ◽  
Evaluation Framework ◽  
Metabolic Energy ◽  
Evaluation Index ◽  
Optimality Principle ◽  
Upper Arm ◽  
Reaching Movement ◽  
Effective Power ◽  
Arm Reaching ◽  
Motor Paralysis

Powered exoskeletons have been proposed and developed in various works with the aim of compensating for motor paralysis or reducing weight, workload, or metabolic energy consumption. However, development of the power-assist system depends on the development and evaluation of real powered exoskeletons, and few studies have evaluated the performance of the power-assist system by means of computer simulation. In this paper, we propose an evaluation framework based on computer simulation for the development of an effective power-assist system and demonstrate an analysis of a power-assisted upper-arm reaching movement. We employed the optimality principle to obtain the adapted movements of humans for power-assist systems and compared the performances of power- and non-power-assisted movements in terms of the evaluation index of the power-assist system.

scholarly journals The duration of reaching movement is longer than predicted by minimum variance

2016 ◽  
Vol 116 (5) ◽  
pp. 2342-2345 ◽  
Author(s):  
Chunji Wang ◽  
Yupeng Xiao ◽  
Etienne Burdet ◽  
James Gordon ◽  
Nicolas Schweighofer
Keyword(s):  
Minimum Variance ◽  
Reaching Movements ◽  
Movement Duration ◽  
Slow Movement ◽  
Reaching Movement ◽  
End Point ◽  
Parsimonious Explanation ◽  
Arm Reaching ◽  
The Central Nervous System ◽  
Duration Condition

Whether the central nervous system minimizes variability or effort in planning arm movements can be tested by measuring the preferred movement duration and end-point variability. Here we conducted an experiment in which subjects performed arm reaching movements without visual feedback in fast-, medium-, slow-, and preferred-duration conditions. Results show that 1) total end-point variance was smallest in the medium-duration condition and 2) subjects preferred to carry out movements that were slower than this medium-duration condition. A parsimonious explanation for the overall pattern of end-point errors across fast, medium, preferred, and slow movement durations is that movements are planned to minimize effort as well as end-point error due to both signal-dependent and constant noise.

scholarly journals Online modification of goal-directed control in human reaching movements

2021 ◽  
Author(s):  
Antoine De Comite ◽  
Frédéric Crevecoeur ◽  
Philippe Lefèvre
Keyword(s):  
Control Strategies ◽  
Control Policy ◽  
Visual Display ◽  
Surface Emg ◽  
Movement Planning ◽  
Reaching Movements ◽  
Reaching Movement ◽  
Flexible Control ◽  
Task Goal ◽  
Sudden Appearance

Humans are able to perform very sophisticated reaching movements in a myriad of contexts based on flexible control strategies influenced by the task goal and environmental constraints such as obstacles. However, it remains unknown whether these control strategies can be adjusted online. The objective of this study was to determine whether the factors which determine control strategies during planning also modify the execution of an ongoing movement following sudden changes in task demand. More precisely, we investigated whether, and at which latency, feedback responses to perturbation loads followed the change in the structure of the goal target or environment. We changed the target width (square or rectangle) to alter the task redundancy, or the presence of obstacles to induce different constraints on the reach path, and assessed based on surface EMG recordings when the change in visual display altered the feedback response to mechanical perturbations. Task-related EMG responses were detected within 150 ms of a change in target shape. Considering visuomotor delays of ~ 100 ms, these results suggest that it takes 50 ms to change control policy within a trial. An additional 30 ms delay was observed when the change in context involved sudden appearance or disappearance of obstacles. Overall, our results demonstrate that the control policy within a reaching movement is not static: contextual factors which influence movement planning also influence movement execution at surprisingly short latencies. Moreover, the additional 30 ms associated with obstacles suggest that these two types of changes may be mediated via distinct processes.

Influence of Viscous Loads on Motor Planning

2007 ◽  
Vol 98 (2) ◽  
pp. 870-877 ◽  
Author(s):  
Kurt A. Thoroughman ◽  
Wei Wang ◽  
Dimitre N. Tomov
Keyword(s):  
Force Field ◽  
Human Behavior ◽  
Motor Planning ◽  
Movement Planning ◽  
Viscous Force ◽  
Learned Behavior ◽  
Viscous Forces ◽  
Minimum Jerk ◽  
Human Arm ◽  
Minimum Torque

Here we computationally investigate how encumbering the hand could alter predictions made by the minimum torque change (MTC) and minimum endpoint variance hypotheses (MEPV) of movement planning. After minutes of training, people have made arm trajectories in a robot-generated viscous force field that were similar to previous baseline trajectories without the force field. We simulate the human arm interacting with this viscous load. We found that the viscous forces clearly differentiated MTC and MEPV predictions from both minimum-jerk predictions and from human behavior. We conclude that learned behavior in the viscous environment could arise from minimizing kinematic costs but could not arise from a minimization of either torque change or endpoint variance.

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