Two functionally different synergies during arm reaching movements involving the trunk

1995 ◽  
Vol 73 (5) ◽  
pp. 2120-2122 ◽  
Author(s):  
S. Ma ◽  
A. G. Feldman
Keyword(s):  
Motor Control ◽  
Degrees Of Freedom ◽  
Arm Movements ◽  
The Other ◽  
Reaching Movements ◽  
Positional Error ◽  
Trunk Motion ◽  
Arm Reaching ◽  
Trunk Movements ◽  
The Right

1. To address the problem of the coordination of a redundant number of degrees of freedom in motor control, we analyzed the influence of voluntary trunk movements on the arm endpoint trajectory during reaching. 2. Subjects made fast noncorrected planar movements of the right arm from a near to a far target located in the ipsilateral work space at a 45 degrees angle to the sagittal midline of the trunk. These reaching movements were combined with a forward or a backward sagittal motion of the trunk. 3. The direction, positional error, curvature, and velocity profile of the endpoint trajectory remained invariant regardless of trunk movements. Trunk motion preceded endpoint motion by approximately 175 ms, continued during endpoint movement to the target, and outlasted it by 200 ms. This sequence of trunk and arm movements was observed regardless of the direction of the endpoint trajectory (to or from the far target) or trunk movements (forward or backward). 4. Our data imply that reaching movements result from two control synergies: one coordinates trunk and arm movements leaving the position of the endpoint unchanged, and the other produces interjoint coordination shifting the arm endpoint to the target. The use of functionally different synergies may underlie a solution of the redundancy problem.

scholarly journals Handedness results from complementary hemispheric dominance, not global hemispheric dominance: evidence from mechanically coupled bilateral movements

2018 ◽  
Vol 120 (2) ◽  
pp. 729-740 ◽  
Author(s):  
Elizabeth J. Woytowicz ◽  
Kelly P. Westlake ◽  
Jill Whitall ◽  
Robert L. Sainburg
Keyword(s):  
Motor Control ◽  
Dynamic Control ◽  
The Other ◽  
Hemispheric Dominance ◽  
Control Mechanisms ◽  
Left Hand ◽  
Right Hand ◽  
Other Hand ◽  
Task Component ◽  
The Right

Two contrasting views of handedness can be described as 1) complementary dominance, in which each hemisphere is specialized for different aspects of motor control, and 2) global dominance, in which the hemisphere contralateral to the dominant arm is specialized for all aspects of motor control. The present study sought to determine which motor lateralization hypothesis best predicts motor performance during common bilateral task of stabilizing an object (e.g., bread) with one hand while applying forces to the object (e.g., slicing) using the other hand. We designed an experimental equivalent of this task, performed in a virtual environment with the unseen arms supported by frictionless air-sleds. The hands were connected by a spring, and the task was to maintain the position of one hand while moving the other hand to a target. Thus the reaching hand was required to take account of the spring load to make smooth and accurate trajectories, while the stabilizer hand was required to impede the spring load to keep a constant position. Right-handed subjects performed two task sessions (right-hand reach and left-hand stabilize; left-hand reach and right-hand stabilize) with the order of the sessions counterbalanced between groups. Our results indicate a hand by task-component interaction such that the right hand showed straighter reaching performance whereas the left hand showed more stable holding performance. These findings provide support for the complementary dominance hypothesis and suggest that the specializations of each cerebral hemisphere for impedance and dynamic control mechanisms are expressed during bilateral interactive tasks. NEW & NOTEWORTHY We provide evidence for interlimb differences in bilateral coordination of reaching and stabilizing functions, demonstrating an advantage for the dominant and nondominant arms for distinct features of control. These results provide the first evidence for complementary specializations of each limb-hemisphere system for different aspects of control within the context of a complementary bilateral task.

scholarly journals Effects of target location and uncertainty on reaching movements in standing position

2012 ◽  
Vol 26 (3) ◽  
pp. 485-493 ◽  
Author(s):  
Luiz de França Bahia Loureiro Junior ◽  
Sandra Maria Sbeghen Ferreira de Freitas ◽  
Paulo Barbosa de Freitas
Keyword(s):  
Reaction Time ◽  
Target Location ◽  
Movement Time ◽  
Target Position ◽  
Standing Position ◽  
Reaching Movements ◽  
Radial Error ◽  
Arm Reaching ◽  
The Right

The effects of target location and uncertainty of target position on reaching movements while standing were investigated. Ten healthy, right-handed adults stood facing a 17'' touchscreen. They were instructed to press with their right index fingertip a push bottom and touch the center of the target displayed on the screen after it was lighted on, moving quickly their arm. The target was shown either ipsi- or contralateral to the right arm and either in a certain or uncertain position. Reaction time (RT), movement time (MT), and radial error (RE) were assessed. Results revealed shorter RT (≈ 35 ms) and smaller RE (≈ 0.19 cm) for certain than for uncertain condition and slightly longer RT (≈ 8 ms) and MT (≈ 18 ms) for reaches towards the contralateral target. In conclusion, the findings of this study showing the effect of uncertainty of target location as well as target position are also applied to arm reaching in standing position.

scholarly journals Vigor of reaching, walking, and gazing movements: on the consistency of interindividual differences

2020 ◽  
Vol 123 (1) ◽  
pp. 234-242
Author(s):  
Ombeline Labaune ◽  
Thomas Deroche ◽  
Caroline Teulier ◽  
Bastien Berret
Keyword(s):  
Decision Making ◽  
Motor Control ◽  
Basal Ganglia ◽  
Reaching Movements ◽  
Neural Pathways ◽  
Motor Tasks ◽  
Interindividual Differences ◽  
Arm Reaching ◽  
Highly Correlated ◽  
First Time

Movement vigor is an important feature of motor control that is thought to originate from cortico-basal ganglia circuits and processes shared with decision-making, such as temporal reward discounting. Accordingly, vigor may be related to one’s relationship with time, which may, in turn, reflect a general trait-like feature of individuality. While significant interindividual differences of vigor have been typically reported for isolated motor tasks, little is known about the consistency of such differences across tasks and movement effectors. Here, we assessed interindividual consistency of vigor across reaching (both dominant and nondominant arm), walking, and gazing movements of various distances within the same group of 20 participants. Given distinct neural pathways and biomechanical specificities of each movement modality, a significant consistency would corroborate the trait-like aspect of vigor. Vigor scores for dominant and nondominant arm movements were found to be highly correlated across individuals. Vigor scores of reaching and walking were also significantly correlated across individuals, indicating that people who reach faster than others also tend to walk faster. At last, vigor scores of saccades were uncorrelated with those of reaching and walking, reaffirming that the vigor of stimulus-elicited eye saccades is distinct. These findings highlight the trait-like aspect of vigor for reaching movements with either arms and, to a lesser extent, walking. NEW & NOTEWORTHY Robust interindividual differences of movement vigor have been reported for arm reaching and saccades. Beyond biomechanics, personality trait-like characteristics have been proposed to account for those differences. Here, we examined for the first time the consistency of interindividual differences of vigor during dominant/nondominant arm reaching, walking, and gazing to assess the trait-like aspect of vigor. We found a significant consistency of vigor within our group of individuals for all tested tasks/effectors except saccades.

scholarly journals Effects of Simulated Microgravity and Hypergravity Conditions on Arm Movements in Normogravity

2021 ◽  
Vol 15 ◽  
Author(s):  
Marko Jamšek ◽  
Tjaša Kunavar ◽  
Gunnar Blohm ◽  
Daichi Nozaki ◽  
Charalambos Papaxanthis ◽  
...  
Keyword(s):  
Parabolic Flight ◽  
Arm Movements ◽  
Reaching Movements ◽  
Kinematic Parameters ◽  
Altered Gravity ◽  
Body Experience ◽  
Arm Reaching ◽  
Movement Characteristics ◽  
Environmental Force ◽  
Microgravity Conditions

The human sensorimotor control has evolved in the Earth’s environment where all movement is influenced by the gravitational force. Changes in this environmental force can severely impact the performance of arm movements which can be detrimental in completing certain tasks such as piloting or controlling complex vehicles. For this reason, subjects that are required to perform such tasks undergo extensive training procedures in order to minimize the chances of failure. We investigated whether local gravity simulation of altered gravitational conditions on the arm would lead to changes in kinematic parameters comparable to the full-body experience of microgravity and hypergravity onboard a parabolic flight. To see if this would be a feasible approach for on-ground training of arm reaching movements in altered gravity conditions we developed a robotic device that was able to apply forces at the wrist in order to simulate micro- or hypergravity conditions for the arm while subjects performed pointing movements on a touch screen. We analyzed and compared the results of several kinematic parameters along with muscle activity using this system with data of the same subjects being fully exposed to microgravity and hypergravity conditions on a parabolic flight. Both in our simulation and in-flight, we observed a significant increase in movement durations in microgravity conditions and increased velocities in hypergravity for upward movements. Additionally, we noted a reduced accuracy of pointing both in-flight and in our simulation. These promising results suggest, that locally simulated altered gravity can elicit similar changes in some movement characteristics for arm reaching movements. This could potentially be exploited as a means of developing devices such as exoskeletons to aid in training individuals prior to undertaking tasks in changed gravitational conditions.

A Fragment by Onesimos

1976 ◽  
Vol 96 ◽  
pp. 162-163
Author(s):  
D. J. R. Williams
Keyword(s):  
The Other ◽  
Arm Reaching ◽  
Private Collection ◽  
The Right

The purpose of this note is to make known a fine pair of joining fragments, one in the Louvre, the other in a private collection in Oxford, which come from the outside of a cup by Onesimos. The Louvre fragment, Cp. 11342, listed in the second edition of J. D. Beazley's Attic Red-figure Vase-Painters but not previously figured, gives part of a male leaning to the right on a knotted stick. He is draped in an himation with a two-line border pattern. His chest is frontal but he twists to the right, his right arm reaching across and down to the right, while his left, comfortably tucked in the material of the himation, rests on the top of the stick. The new Oxford fragment adds the head of the youth, his right shoulder and the tops of two of the billows of the himation as it passes over the upper part of the left arm.

Assessment of knowledge of oral health hygiene among coastal guards in the port trust of south Tamil Nadu - A public health awareness survey

2020 ◽  
Vol 11 (SPL3) ◽  
pp. 1861-1868
Author(s):  
Bianca Princeton ◽  
Abilasha R ◽  
Preetha S
Keyword(s):  
Lung Cancer ◽  
Oral Health ◽  
Oral Hygiene ◽  
Tamil Nadu ◽  
Asbestos Exposure ◽  
The Other ◽  
Oral Manifestations ◽  
Illegal Activities ◽  
The Right ◽  
Oral Hygiene Habits

Oral hygiene is defined as the practice of keeping the mouth clean and healthy, by brushing and flossing to prevent the occurrence of any gum diseases like periodontitis or gingivitis. The main aim of oral health hygiene is to prevent the buildup of plaque, which is defined as a sticky film of bacteria and food formed on the teeth. The coastal guard is an official who is employed to watch the sea near a coast for ships that are in danger or involved with illegal activities. Coastal guards have high possibilities of being affected by mesothelioma or lung cancer due to asbestos exposure. So, a questionnaire consisting of 20 questions was created and circulated among a hundred participants who were coastal guards, through Google forms. The responses were recorded and tabulated in the form of bar graphs. Out of a hundred participants, 52.4% were not aware of the fact that coastal guards have high chances of developing lung cancer and Mesothelioma. 53.7% were aware of the other oral manifestations of lung cancer other than bleeding gums. Majority of the coastal guards feel that they are given enough information about dental hygiene protocols. Hence, to conclude, oral hygiene habits have to be elaborated using various tools in the right manner to ensure better health of teeth and gums.

JUAL BELI TANAH YANG DILAKUKAN TANPA AKTA PPAT

2018 ◽  
Vol 4 (1) ◽  
pp. 89-107
Author(s):  
Cheri Bayuni Budjang
Keyword(s):  
Everyday Life ◽  
Government Regulation ◽  
Land Rights ◽  
The Other ◽  
Legal Certainty ◽  
Land Registration ◽  
The Future ◽  
The Right ◽  
Laws And Regulations

Buying and selling is a way to transfer land rights according to the provisions in Article 37 paragraph (1) of Government Regulation Number 24 of 1997 concerning Land Registration which must include the deed of the Land Deed Making Official to register the right of land rights (behind the name) to the Land Office to create legal certainty and minimize the risks that occur in the future. However, in everyday life there is still a lot of buying and selling land that is not based on the laws and regulations that apply, namely only by using receipts and trust in each other. This is certainly very detrimental to both parties in the transfer of rights (behind the name), especially if the other party is not known to exist like the Case in Decision Number 42 / Pdt.G / 2010 / PN.Mtp

Visual asymmetries during face encoding Increased dwell time and fixations in the upper and left hemifields

2018 ◽  
Author(s):  
Fatima Maria Felisberti
Keyword(s):  
Face Recognition ◽  
Eye Movements ◽  
Visual Field ◽  
Face Processing ◽  
Dwell Time ◽  
The Other ◽  
Environmental Cues ◽  
Reading Habits ◽  
The Right

Visual field asymmetries (VFA) in the encoding of groups rather than individual faces has been rarely investigated. Here, eye movements (dwell time (DT) and fixations (Fix)) were recorded during the encoding of three groups of four faces tagged with cheating, cooperative, or neutral behaviours. Faces in each of the three groups were placed in the upper left (UL), upper right (UR), lower left (LL), or lower right (LR) quadrants. Face recognition was equally high in the three groups. In contrast, the proportion of DT and Fix were higher for faces in the left than the right hemifield and in the upper rather than the lower hemifield. The overall time spent looking at the UL was higher than in the other quadrants. The findings are relevant to the understanding of VFA in face processing, especially groups of faces, and might be linked to environmental cues and/or reading habits.

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