Unilateral practice of a ballistic movement causes bilateral increases in performance and corticospinal excitability

2008 ◽  
Vol 104 (6) ◽  
pp. 1656-1664 ◽  
Author(s):  
Timothy J. Carroll ◽  
Michael Lee ◽  
Marlene Hsu ◽  
Janel Sayde
Keyword(s):  
Performance Testing ◽  
Conclusive Evidence ◽  
Corticospinal Excitability ◽  
Control Group ◽  
Ballistic Performance ◽  
Opposite Hemisphere ◽  
Left Hand ◽  
Performance Improvements ◽  
Right Hand ◽  
The Right

It has long been known that practicing a task with one limb can result in performance improvements with the opposite, untrained limb. Hypotheses to account for cross-limb transfer of performance state that the effect is mediated either by neural adaptations in higher order control centers that are accessible to both limbs, or that there is a “spillover” of neural drive to the opposite hemisphere that results in bilateral adaptation. Here we address these hypotheses by assessing performance and corticospinal excitability in both hands after unilateral practice of a ballistic finger movement. Participants ( n = 9) completed 300 practice trials of a ballistic task with the right hand, the aim of which was to maximize the peak abduction acceleration of the index finger. Practice caused a 140% improvement in right-hand performance and an 82% improvement for the untrained left hand. There were bilateral increases in the amplitude of responses to transcranial magnetic stimulation, but increased corticospinal excitability was not correlated with improved performance. There were no significant changes in corticospinal excitability or task performance for a control group that did not train ( n = 9), indicating that performance testing for the left hand alone did not induce performance or corticospinal effects. Although the data do not provide conclusive evidence whether increased corticospinal excitability in the untrained hand is causally related to the cross-transfer of ballistic performance, the finding that ballistic practice can induce bilateral corticospinal adaptations may have important clinical implications for movement rehabilitation.

scholarly journals The Relationship between Second-to-Fourth Digit Ratios, Attention-Deficit/Hyperactivity Disorder Symptoms, Aggression, and Intelligence Levels in Boys with Attention-Deficit/Hyperactivity Disorder

2020 ◽  
Vol 17 (6) ◽  
pp. 596-602
Author(s):  
Ümit Işık ◽  
Faruk Kılıç ◽  
Evrim Aktepe ◽  
Bilal Tanrıtanır
Keyword(s):  
Attention Deficit Hyperactivity Disorder ◽  
Attention Deficit ◽  
Rating Scales ◽  
Control Group ◽  
Left Hand ◽  
Hyperactivity Disorder ◽  
Right Hand ◽  
Interesting Study ◽  
Treatment Naïve ◽  
The Right

Objective Observations of sex differences have led some scientists to doubt whether the neuroendocrine system is involved in attentiondeficit/hyperactivity disorder (ADHD) etiology. One of the interesting study subjects in this context is prenatal steroid hormone exposure. The aim of the present study was to replicate and extend previous work by addressing two research questions: 1) Are second-tofourth digit (2D:4D) ratios lower in ADHD than in controls? 2) Is there a correlation between 2D:4D ratios and symptoms of ADHD, aggression and intelligence scores in boys with ADHD?Methods The study included 100 treatment-naive male children diagnosed with ADHD and 55 healthy male children. We measured the ratios of 2D:4D and administered a Wechsler Intelligence Scale for Children-Revised to assess IQ scores, as well as behavioral rating scales, in children with ADHD and comparison individuals.Results We observed lower 2D:4D ratios in the right hand in ADHD in comparison to the control group. The left-hand ratios of 2D:4D, however, did not differ between ADHD and control groups. There were negative correlations between the left-hand 2D:4D ratios and the hyperactivity scores. However, no significant correlation was detected between right-hand 2D:4D ratios and the psychological questionnaire scores.Conclusion These results provide further evidence that fetal androgen exposure may contribute to the pathophysiology of ADHD, at least in boys.

scholarly journals Effects of Repetitive Handgrip Training on Endurance, Specificity, and Cross–Education

1999 ◽  
Vol 79 (5) ◽  
pp. 467-475 ◽  
Author(s):  
Richard K Shields ◽  
Ken C Leo ◽  
Andrew J Messaros ◽  
Virend K Somers
Keyword(s):  
Training Program ◽  
Training Group ◽  
Control Group ◽  
Left Hand ◽  
Low Level ◽  
Right Hand ◽  
Cross Education ◽  
The Right ◽  
Level Training ◽  
Regular Training

Abstract Background and Purpose. Exercise programs are more likely to be successful when they are based on research that predicts the outcomes of such training. This study determined the effect of submaximal rhythmic handgrip training on rhythmic handgrip endurance or work (RHW), isometric handgrip endurance time (IHE), and maximal voluntary isometric contraction for the handgrip force (MVIC) (in newtons). Subjects. Twenty–four male subjects (mean age=26.2 years) with right–hand dominance were randomly assigned to a regular training group (n=8), a low–level training group (n=8), or a control group (n=8). Methods. Rhythmic handgrip work, IHE, and MVIC were determined bilaterally before and after 6 weeks of a rhythmic right handgrip training program using 30% of MVIC. The low-level training group performed daily training with a near–zero load (<0.005% of MVIC). Results. There was a 1,232% increase in RHW and an 8% decrease in IHE after the training program using 30% of MVIC for the right hand. The left hand showed a 43% increase in RHW after training, whereas the low–level training group showed a 35% increase in RHW. No differences were found between the change in the left=hand RHW of the regular training group and the change in the right–hand RHW of the low–level training group, but both measurements were greater than the change in the control group (6.4%). Conclusion and Discussion. Submaximal handgrip endurance training at 30% of MVIC had a minimal effect on submaximal IHE and MVIC of the handgrip, but it had a large effect on RHW of the trained extremity. The regular training group and the low–level training group showed similar increases in cross–education, suggesting that cross–education during endurance training is not intensity–dependent.

Absence of cross-limb transfer of performance gains following ballistic motor practice in older adults

2011 ◽  
Vol 110 (1) ◽  
pp. 166-175 ◽  
Author(s):  
Mark R. Hinder ◽  
Matthew W. Schmidt ◽  
Michael I. Garry ◽  
Timothy J. Carroll ◽  
Jeffery J. Summers
Keyword(s):  
Older Adults ◽  
Intracortical Inhibition ◽  
Young Group ◽  
Left Hand ◽  
Performance Improvements ◽  
Rehabilitation Programs ◽  
Right Hand ◽  
Motor Practice ◽  
The Right ◽  
Performance Gains

The phenomenon of cross-limb transfer, in which unilateral strength training can result in bilateral strength gains, has recently been tested for ballistic movements. Performance gains associated with repetitive motor practice, and the associated transfer, occur within a few minutes. In this study, young and older adults were trained to perform ballistic abductions of their dominant (right) index finger as quickly as possible. Performance was assessed bilaterally before, during, and after this training. Both groups exhibited large performance gains in the right hand as a result of training ( P < 0.001; young 84% improvement, older 70% improvement), which were not significantly different between groups ( P = 0.40). Transcranial magnetic stimulation revealed that the performance improvements were accompanied by increases in excitability, together with decreases in intracortical inhibition, of the projections to both the trained muscle and the homologous muscle in the contralateral limb ( P < 0.05). The young group also exhibited performance improvements as a result of cross-limb transfer in the left (untrained) hand ( P < 0.005), equivalent to 75% of the performance increase in the trained hand. In contrast, there were no significant performance gains in the left hand for the older group ( P = 0.23). This was surprising given that the older group exhibited a significantly greater degree of mirror activity than the young group ( P < 0.01) in the left first dorsal interosseus muscle (FDI) during right hand movements. Our findings suggest that older adults exhibit a reduced capacity for cross-limb transfer, which may have implications for motor rehabilitation programs after stroke.

A Comparative Analysis of Dermatoglyphic Traits on Patients with Chronic Kidney Disease

2018 ◽  
Vol 9 (06) ◽  
pp. 20479-20483
Author(s):  
Manandhar B ◽  
Raman R
Keyword(s):  
Chronic Kidney Disease ◽  
Kidney Disease ◽  
Control Group ◽  
Left Hand ◽  
Medical Disorders ◽  
Right Hand ◽  
Ulnar Loop ◽  
Ridge Pattern ◽  
Loop Pattern ◽  
The Right

Background: Dermatoglyphic features have been associated with numerous medical disorders.. This study is an effort to determine the association between dermatoglyphics and chronic kidney disease. Objectives:  To record and compare the dermatoglyphic pattern in patients of chronic kidney disease and in control group Methods: A case control descriptive study was conducted over six months period on 100 patients with chronic kidney disease and 100 individuals with no evidence of kidney disease in Hemodialysis Department of National Dialysis Centre situated in Kantipur General Hospital, Basundhara, Kathmandu.Patient’s hands were cleaned with soap and water. Once dried, black duplicating ink was applied on fingers and palm. Finger tips followed by palm were recorded on white A4 size paper. Frequency of each ridge pattern analysis was done and paired t-test was performed using SPSS version 16. Results: The distribution of frequency and percentage of ulnar loop pattern in right hand of patients with chronic kidney disease was 350(70%) whereas the distribution of ulnar loop pattern in left hand was 282(56.4%). Conclusion: The predominant fingerprint pattern in patients with chronic kidney disease was found as ulnar loop but the increased frequency of ulnar loop was recorded in right hand of chronic kidney disease patients as compared to the right hand of control group.

scholarly journals Improving motor performance without training: the effect of combining mirror visual feedback with transcranial direct current stimulation

2015 ◽  
Vol 113 (7) ◽  
pp. 2383-2389 ◽  
Author(s):  
Erik von Rein ◽  
Maike Hoff ◽  
Elisabeth Kaminski ◽  
Bernhard Sehm ◽  
Christopher J. Steele ◽  
...  
Keyword(s):  
Visual Feedback ◽  
Direct Current ◽  
Transcranial Direct Current Stimulation ◽  
Motor Performance ◽  
Left Hand ◽  
Direct Current Stimulation ◽  
Performance Improvements ◽  
Right Hand ◽  
Mirror Visual Feedback ◽  
The Right

Mirror visual feedback (MVF) during motor training has been shown to improve motor performance of the untrained hand. Here we thought to determine if MVF-induced performance improvements of the left hand can be augmented by upregulating plasticity in right primary motor cortex (M1) by means of anodal transcranial direct current stimulation (a-tDCS) while subjects trained with the right hand. Participants performed a ball-rotation task with either their left (untrained) or right (trained) hand on two consecutive days ( days 1 and 2). During training with the right hand, MVF was provided concurrent with two tDCS conditions: group 1 received a-tDCS over right M1 ( n = 10), whereas group 2 received sham tDCS (s-tDCS, n = 10). On day 2, performance was reevaluated under the same experimental conditions compared with day 1 but without tDCS. While baseline performance of the left hand ( day 1) was not different between groups, a-tDCS exhibited stronger MVF-induced performance improvements compared with s-tDCS. Similar results were observed for day 2 (without tDCS application). A control experiment ( n = 8) with a-tDCS over right M1 as outlined above but without MVF revealed that left hand improvement was significantly less pronounced than that induced by combined a-tDCS and MVF. Based on these results, we provide novel evidence that upregulating activity in the untrained M1 by means of a-tDCS is capable of augmenting MVF-induced performance improvements in young normal volunteers. Our findings suggest that concurrent MVF and tDCS might have synergistic and additive effects on motor performance of the untrained hand, a result of relevance for clinical approaches in neurorehabilitation and/or exercise science.

Editorial Note

1946 ◽  
Vol 11 (1) ◽  
pp. 2-2
Keyword(s):  
Editorial Note ◽  
Speech Sounds ◽  
Left Hand ◽  
Hand Column ◽  
Right Hand ◽  
Infant Speech ◽  
The Right

In the article “Infant Speech Sounds and Intelligence” by Orvis C. Irwin and Han Piao Chen, in the December 1945 issue of the Journal, the paragraph which begins at the bottom of the left hand column on page 295 should have been placed immediately below the first paragraph at the top of the right hand column on page 296. To the authors we express our sincere apologies.

scholarly journals Hand Preference and Performance in Basketball Tasks

2019 ◽  
Vol 16 (22) ◽  
pp. 4336 ◽  
Author(s):  
Emanuela Gualdi-Russo ◽  
Natascia Rinaldo ◽  
Alba Pasini ◽  
Luciana Zaccagni
Keyword(s):  
Professional Training ◽  
Factor Model ◽  
Hand Preference ◽  
Control Group ◽  
Basketball Players ◽  
Confirmatory Factor Analyses ◽  
Left Hand ◽  
Confirmatory Factor ◽  
And Performance ◽  
The Right

The aims of this study were to develop and validate an instrument to quantitatively assess the handedness of basketballers in basketball tasks (Basketball Handedness Inventory, BaHI) and to compare it with their handedness in daily activities by the Edinburgh Handedness Inventory (EHI). The participants were 111 basketballers and 40 controls. All subjects completed the EHI and only basketballers filled in the BaHI. To validate the BaHI, a voluntary subsample of basketballers repeated the BaHI. Exploratory and confirmatory factor analyses supported a two-factor model. Our results show that: (i) Handedness score (R) in daily actions did not differ between basketball players (R by EHI = 69.3 ± 44.6) and the control group (R by EHI = 64.5 ± 58.6); (ii) basketballers more frequently favored performing certain sport tasks with the left hand or mixed hands (as highlighted by R by BaHI = 50.1 ± 47.1), although their choice was primarily the right hand in everyday gestures; and (iii) this preference was especially true for athletes at the highest levels of performance (R by BaHI of A1 league = 38.6 ± 58.3) and for those playing in selected roles (point guard’s R = 29.4 ± 67.4). Our findings suggest that professional training induces handedness changes in basketball tasks. The BaHI provides a valid and reliable measure of the skilled hand in basketball. This will allow coaches to assess mastery of the ball according to the hand used by the athlete in the different tasks and roles.

scholarly journals Digit Variability in Carotenoid Scores Obtained with the Veggie Meter: A Pilot Study (P02-001-19)

2019 ◽  
Vol 3 (Supplement_1) ◽  
Author(s):  
Velarie Ansu ◽  
Stephanie Dickinson ◽  
Alyce Fly
Keyword(s):  
Indiana University ◽  
Left Hand ◽  
Funding Sources ◽  
Right Hand ◽  
Period Data ◽  
The Mean ◽  
The Right ◽  
Post Hoc ◽  
Main Effects ◽  
Mean Square Errors

Abstract Objectives To determine which digit and hand have the highest and lowest skin carotenoid scores, to compare inter-and-intra-hand variability of digits, and to determine if results are consistent with another subject. Methods Two subjects’ first(F1), second(F2), third(F3) and fifth(F5) digits on both hands were measured for skin carotenoids with a Veggie Meter, for 3 times on each of 18 days over a 37-day period. Data were subjected to ANOVA in a factorial treatment design to determine main effects for hand (2 levels), digits (4), and days (18) along with interactions. Differences between digits were determined by Tukey's post hoc test. Results There were significant hand x digit, hand x day, digit x day, and hand x digit x day interactions and significant simple main effects for hand, digit, and day (all P < 0.001). Mean square errors were 143.67 and 195.62 for subject A and B, respectively, which were smaller than mean squares for all main effects and interactions. The mean scores ± SD for F1, F2, F3, and F5 digits for the right vs left hands for subject A were F1:357.13 ± 45.97 vs 363.74 ± 46.94, F2:403.17 ± 44.77 vs. 353.20 ± 44.13, F3:406.76 ± 43.10 vs. 357.11 ± 45.13, and F5:374.95 ± 53.00 vs. 377.90 ± 47.38. For subject B, the mean scores ± SD for digits for the right vs left hands were F1:294.72 ± 61.63 vs 280.71 ± 52.48, F2:285.85 ± 66.92 vs 252.67 ± 67.56, F3:268.56 ± 57.03 vs 283.22 ± 45.87, and F5:288.18 ± 34.46 vs 307.54 ± 40.04. The digits on the right hand of both subjects had higher carotenoid scores than those on the left hands, even though subjects had different dominant hands. Subject A had higher skin carotenoid scores on the F3 and F2 digits for the right hand and F5 on the left hand. Subject B had higher skin carotenoid scores on F5 (right) and F1 (left) digits. Conclusions The variability due to hand, digit, and day were all greater than that of the 3 replicates within the digit-day for both volunteers. This indicates that data were not completely random across the readings when remeasuring the same finger. Different fingers displayed higher carotenoid scores for each volunteer. There is a need to conduct a larger study with more subjects and a range of skin tones to determine whether the reliability of measurements among digits of both hands is similar across the population. Funding Sources Indiana University.

The State Policy towards the Homeless in Moldova between the ‘Left Hand’ and the ‘Right Hand’. The Case of Chișinău Shelter

Südosteuropa ◽  
2019 ◽  
Vol 67 (2) ◽  
pp. 175-195
Author(s):  
Petru Negură
Keyword(s):  
Homeless People ◽  
Severe Disabilities ◽  
The State ◽  
Small Scale ◽  
Left Hand ◽  
Right Hand ◽  
Binary Approach ◽  
The One ◽  
The Right ◽  
Depth Interviews

Abstract The Centre for the Homeless in Chișinău embodies on a small scale the recent evolution of state policies towards the homeless in Moldova (a post-Soviet state). This institution applies the binary approach of the state, namely the ‘left hand’ and the ‘right hand’, towards marginalised people. On the one hand, the institution provides accommodation, food, and primary social, legal assistance and medical care. On the other hand, the Shelter personnel impose a series of disciplinary constraints over the users. The Shelter also operates a differentiation of the users according to two categories: the ‘recoverable’ and those deemed ‘irrecoverable’ (persons with severe disabilities, people with addictions). The personnel representing the ‘left hand’ (or ‘soft-line’) regularly negotiate with the employees representing the ‘right hand’ (‘hard-line’) of the institution to promote a milder and a more humanistic approach towards the users. This article relies on multi-method research including descriptive statistical analysis with biographical records of 810 subjects, a thematic analysis of in-depth interviews with homeless people (N = 65), people at risk of homelessness (N = 5), professionals (N = 20) and one ethnography of the Shelter.

scholarly journals The Left Hand Doesn’t Know What the Right Hand Is Doing—or Does It?

Cell Reports ◽  
2016 ◽  
Vol 17 (11) ◽  
pp. 2809-2810
Author(s):  
Jody C. Culham
Keyword(s):  
Left Hand ◽  
Right Hand ◽  
The Right
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