The Influence of Tonic Muscle Activation on Human Jaw Displacement Tremor

1988 ◽  
Vol 67 (8) ◽  
pp. 1081-1085
Author(s):  
R.S. McCarroll ◽  
J.H. De Vries
Keyword(s):  
Individual Variation ◽  
Muscle Activation ◽  
Physiological Basis ◽  
Tonic Muscle ◽  
Tremor Frequency ◽  
The Relationship

Jaw displacement tremor was investigated. Both tremor amplitude and tremor frequency were found to increase with increasing muscle activation. Co-contraction of jaw elevator and jaw depressor muscles was employed in order to vary muscle activation levels without the teeth being in occlusion. Reproducibility of tremor changes was statistically significant for each individual investigated. The relationship between tremor frequency and tremor amplitude, over the range of muscle activation investigated, varied per individual. It is hypothesized that the physiological basis for this inter-individual variation is differences in the development of jaw stiffness with increasing muscle activation between subjects. This explanation may be the basis, at least in part, for the clinical presence of objective jaw stiffness in one subject and its absence in another.

scholarly journals Intraspecific Variation in Maximum Ingested Food Size and Body Mass in Varecia rubra and Propithecus coquereli

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Adam Hartstone-Rose ◽  
Jonathan M. G. Perry
Keyword(s):  
Body Size ◽  
Body Mass ◽  
Individual Variation ◽  
Size Variation ◽  
Maximum Size ◽  
Least Squares Regression ◽  
Scaling Relationship ◽  
Varecia Rubra ◽  
Food Size ◽  
The Relationship

In a recent study, we quantified the scaling of ingested food size (Vb )—the maximum size at which an animal consistently ingests food whole—and found that Vb scaled isometrically between species of captive strepsirrhines. The current study examines the relationship between Vb and body size within species with a focus on the frugivorous Varecia rubra and the folivorous Propithecus coquereli. We found no overlap in Vb between the species (all V. rubra ingested larger pieces of food relative to those eaten by P. coquereli), and least-squares regression of Vb and three different measures of body mass showed no scaling relationship within each species. We believe that this lack of relationship results from the relatively narrow intraspecific body size variation and seemingly patternless individual variation in Vb within species and take this study as further evidence that general scaling questions are best examined interspecifically rather than intraspecifically.

The relationship between muscle activation and handwriting quality with non-native grip styles

2021 ◽  
Author(s):  
Kristen M. Farris ◽  
Regan E. Fehrenbacher ◽  
Erin L. Hayes ◽  
Ryan R. McEvoy ◽  
Alex P. Smith ◽  
...  
Keyword(s):  
Muscle Activation ◽  
The Relationship

Could Different Directions of Infant Stepping Be Controlled by the Same Locomotor Central Pattern Generator?

2000 ◽  
Vol 83 (5) ◽  
pp. 2814-2824 ◽  
Author(s):  
Tania Lamb ◽  
Jaynie F. Yang
Keyword(s):  
Central Pattern Generator ◽  
Muscle Activation ◽  
Pattern Generator ◽  
Swing Phase ◽  
Smooth Transition ◽  
Cycle Duration ◽  
Human Infants ◽  
Activation Patterns ◽  
Muscle Activation Patterns ◽  
The Relationship

This study examined the idea of whether the same central pattern generator (CPG) for locomotion can control different directions of walking in humans. Fifty-two infants, aged 2–11 mo, were tested. Infants were supported to walk on a treadmill at a variety of speeds. If forward stepping was elicited, stepping in the other directions (primarily sideways and backward) was attempted. The orientation of the infant on the treadmill belt determined the direction of stepping. In some infants, we also attempted to obtain a smooth transition from one direction to another by gradually changing the orientation of the infant during a stepping sequence. Limb segment motion and surface electromyography from the muscles of the lower limb were recorded. Most infants who showed sustained forward walking also could walk in all other directions. Thirty-three of 34 infants tested could step sideways. The success of eliciting backward stepping was 69%. Most of the infants who did not meet our backward stepping criteria did, however, make stepping movements. The different directions of stepping had similar responses to changes in treadmill speed. The relationship between stance and swing phase durations and cycle duration were the same regardless of the direction of stepping across a range of speeds. Some differences were noted in the muscle activation patterns during different directions of walking. For example, the hamstrings were much more active during the swing phase of backward walking compared with forward walking. The quadriceps was more active in the trailing leg during sideways walking. In some infants, we were able to elicit stepping along a continuum of directions. We found no discrete differences in either the electromyographic patterns or the temporal parameters of stepping as the direction of stepping was gradually changed. The results support the idea that the same locomotor CPG controls different directions of stepping in human infants. The fact that most infants were able to step in all directions, the similarity in the response to speed changes, and the absence of any discrete changes as the direction of stepping was changed gradually are all consistent with this hypothesis.

Basic and Translational Neuroscience of Childhood-Onset Dystonia: A Control-Theory Perspective

2018 ◽  
Vol 41 (1) ◽  
pp. 41-59 ◽  
Author(s):  
Terence D. Sanger
Keyword(s):  
Muscle Activation ◽  
Distributed Network ◽  
Childhood Onset ◽  
Specific Mechanism ◽  
Involuntary Muscle ◽  
Postural Stabilization ◽  
Reflex Gain ◽  
Cortical Regions ◽  
Mechanism Of Failure ◽  
The Relationship

Dystonia is a collection of symptoms with involuntary muscle activation causing hypertonia, hyperkinetic movements, and overflow. In children, dystonia can have numerous etiologies with varying neuroanatomic distribution. The semiology of dystonia can be explained by gain-of-function failure of a feedback controller that is responsible for stabilizing posture and movement. Because postural control is maintained by a widely distributed network, many different anatomic regions may be responsible for symptoms of dystonia, although all features of dystonia can be explained by uncontrolled activation or hypersensitivity of motor cortical regions that can cause increased reflex gain, inserted postures, or sensitivity to irrelevant sensory variables. Effective treatment of dystonia in children requires an understanding of the relationship between etiology, anatomy, and the specific mechanism of failure of postural stabilization.

Pauses and hesitation phenomena in second language production

2000 ◽  
Vol 127-128 ◽  
pp. 53-69 ◽  
Author(s):  
Jasone Cenoz
Keyword(s):  
Second Language ◽  
Language Proficiency ◽  
Individual Variation ◽  
Language Production ◽  
Filled Pauses ◽  
The Individual ◽  
The Relationship ◽  
Hesitation Phenomena

Abstract This article focuses on the study of pauses in second language production by analysing the frequency of silent and filled pauses and their functions. It also examines the combination of pauses and other hesitation phenomena in second language production and it explores the relationship between pauses and language proficiency. The results confirm that pauses and hesitations are frequent phenomena in second language production and the individual variation in their occurrence. It was also found that pauses are often associated with other hesitation phenomena and that filled and silent pauses can have the same functions.

scholarly journals Traces of Teaching Methods in a Language Class and the Relationship between Teacher’s Intended Learning Outcomes and Students’ Uptake

2017 ◽  
Vol 10 (7) ◽  
pp. 89
Author(s):  
Zahra Mahmoudabadi
Keyword(s):  
Learning Outcomes ◽  
Teaching Methods ◽  
Individual Variation ◽  
Teaching Method ◽  
Language Class ◽  
Instructional Procedures ◽  
Intended Learning Outcomes ◽  
The Relationship

This study has two main objectives: first, to find traces of teaching methods in a language class and second, to study the relationship between intended learning outcomes and uptake, which is defined as what students claim to have learned. In order to identify the teaching method, after five sessions of observation, class activities and procedures were compared with typical techniques of previous methods. The findings showed that the teacher’s method was an eclectic one which mostly followed CLT guidelines along with utilizing techniques from some other methods such as GTM, DM, and ALM. In the study of uptake, the students were given uptake charts (for vocabulary and grammar items) at the end of each session and based on their reports of uptaken items, it was concluded that uptake can reflect the intended learning outcomes and instructional procedures to a good extent, specifically for grammar items. Regarding idiosyncrasy of uptake, it was not found to be remarkably idiosyncratic, i.e. there was not much individual variation among learners’ reported uptake.

Finger Tremor and Extrapyramidal Side Effects of Neuroleptic Drugs

1979 ◽  
Vol 134 (5) ◽  
pp. 488-493 ◽  
Author(s):  
Paul Collins ◽  
Ian Lee ◽  
Peter Tyrer
Keyword(s):  
Side Effects ◽  
Negative Relationship ◽  
Peak Frequency ◽  
Neuroleptic Drug ◽  
Neuroleptic Drugs ◽  
Extrapyramidal Side Effects ◽  
Significant Negative Relationship ◽  
Tremor Frequency ◽  
Finger Tremor ◽  
The Relationship

SummaryFinger tremor and extrapyramidal side-effects (EPSEs) were measured in seven patients before and during neuroleptic drug treatment to assess the relationship between the onset of EPSEs and changes in finger tremor spectra. Tremor and EPSEs were also measured in twelve patients stabilized on neuroleptic drugs to determine whether tremor could provide a reliable index of the presence and severity of extrapyramidal system disturbance. A downward shift in peak tremor frequency was noted within 48 hours of starting neuroleptic drug therapy, usually before the onset of EPSEs, and a significant negative relationship between the severity of EPSEs and tremor frequency (but not tremor amplitude). The peak frequency of finger tremor is thus a sensitive index of extrapyramidal disturbance and might be of value in predicting which patients taking neuroleptic drugs need anti-parkinsonian therapy.

ECOLOGICAL STUDY OF THE PEAT BOGS OF EASTERN NORTH AMERICA: III. NOTES ON THE BEHAVIOR OF CHAMAEDAPHNE CALYCULATA

1956 ◽  
Vol 34 (1) ◽  
pp. 197-207 ◽  
Author(s):  
Kornelius Lems
Keyword(s):  
Ecological Study ◽  
The Other ◽  
Soil Conditions ◽  
Peat Bogs ◽  
Eastern North America ◽  
Physiological Basis ◽  
Chamaedaphne Calyculata ◽  
Different Types ◽  
The One ◽  
The Relationship

This paper presents data and observations concerning Chamaedaphne calyculata (L.) Moench. (Ericaceae). The branching pattern, the longevity of different types of leaves, and features of flowering are shown to be correlated. The relationship between this complex of features and the habitat is studied, and a few speculations are advanced to explain the physiological basis for the behavior of Chamaedaphne. This study is essentially autecological, and it is hoped that it may constitute a link between the study of soil conditions and the response of plant hormones on the one hand, and phytosociological work in peat bogs on the other hand.

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