Rein tension in novice riders when riding a horse simulator

2017 ◽  
Vol 13 (4) ◽  
pp. 237-242 ◽  
Author(s):  
H.M. Clayton ◽  
B. Smith ◽  
A. Egenvall
Keyword(s):  
Mixed Models ◽  
Sagittal Plane ◽  
Sampling Rate ◽  
Dominant Hand ◽  
Left Handed ◽  
Maximal Tension ◽  
Left And Right ◽  
The Mean ◽  
The Right

This study reports tension in the left and right reins when riding a horse simulator that moved only in the sagittal plane. The objective was to determine whether asymmetries in rein tension of novice riders at the rising trot, canter, and halt were present, and if so, to investigate their relationship with the rider’s handedness. The experimental hypothesis was that rein tension would be higher on the side of the rider’s non-dominant hand. 22 novice riders (19 right-handed; 3 left-handed) rode a horse simulator at halt, rising trot and canter. Rein tension was recorded in both reins at a sampling rate of 1000 Hz for 8 s at each gait. The variables measured in rising trot and canter were minimal and maximal tension, the change between minimal and maximal values and mean tension per step at rising trot or per stride at canter. At halt only mean tension during the 8 s recording was measured. Comparisons between right and left reins and between right-handed and left-handed riders were made using mixed models. The results showed no asymmetries in mean tension at halt. In rising trot and canter all significant differences involved higher tension in the right rein regardless of handedness of the riders. During rising trot the minimum was higher in the right rein over all riders and both the mean and maximal values were higher in the right rein in left-handed riders. In canter left-handed riders had higher mean tension in the right rein. All recorded asymmetries had higher tension in the right rein compared with the left and they were more prevalent in left-handed riders which implies higher tension in the non-dominant hand. Rein tension patterns were not symmetrical on the left and right sides and asymmetries in left-handed riders were not mirrored in right-handed riders.

scholarly journals The Difference of Acetabular Cup Orientation Between Two Surgical Sides After Primary Total Hip Arthroplasty by Right-handed Surgeons

2021 ◽  
Author(s):  
Ao Xiong ◽  
su liu ◽  
Guoqing Li ◽  
Jian Weng ◽  
Deli Wang ◽  
...  
Keyword(s):  
Total Hip Arthroplasty ◽  
Hip Arthroplasty ◽  
Safe Zone ◽  
Dominant Hand ◽  
Acetabular Cup ◽  
Total Hip ◽  
Left And Right ◽  
The Mean ◽  
The Right ◽  
Primary Total Hip Arthroplasty

Abstract Background: We performed the retrospective cohort study to compare the acetabular cup orientation, including anteversion angle (AA) and inclination angle (IA), of dominant hand side and non-dominant hand side after primary total hip arthroplasty (THA) by right-handed orthopedic surgeons. Methods: Between January 2018 and December 2018, 290 patients who aged below 60 years and underwent primary THA were retrospective screened. Patients who had hemiarthroplasty, previous hip surgery, ankylosing spondylitis, developmental dysplasia of hip (DDH, Crowe type-Ⅲ and type-Ⅳ), severe comorbidity, missing information, inferior quality radiographs were excluded. According to the surgery side, all patients were divided into left group and right group. Postoperative plain radiographs were analyzed to compare the AA and IA between left and right side. Univariate and stepwise multivariable linear regression to control included confounding factors. Stratified analysis was performed to identify whether the operation approach can affect the result, including anterolateral (ALA) and posterolateral approach (PLA). Results: The mean AA was 17.7° (range 6.0° to 30.0°) and 21.0° (range 9.5° to 35.0°) for the left and right side respectively. The mean difference was 3.28° (95% CI: 1.92 – 4.64; P<0.001). The mean IA was 41.1° (range 24.0° to 59.0°) and 40.1° (range 20.5° to 56.0°) for the left and right side respectively (P=0.314). 113 patients' AA within the “safe zone” in the left (93.4 %), while the right was 93 patients (82.3 %) (P=0.009). 95 patients' IA within the “safe zone” in the left (78.5 %), while the right was 97 patients (85.8 %) (P=0.144). The IA of ALA group was smaller than PLA group in both sides. The mean difference was 3.98° (95% CI: 1.22 - 6.74; P=0.005). Conclusions: We concluded that AA in left side may be more accurate than right side after primary THA by right-handed surgeons. The IA was no difference between the two sides, while it was smaller in ALA than in PLA. The results are still needed to be verified in future.

Handedness affects Emotional Valence Asymmetry

1989 ◽  
Vol 68 (2) ◽  
pp. 435-441 ◽  
Author(s):  
Richard A. McFarland ◽  
Robert Kennison
Keyword(s):  
Negative Affect ◽  
Hemispheric Asymmetry ◽  
Emotional Responses ◽  
Emotional Valence ◽  
Left Handed ◽  
Two Factors ◽  
Left And Right ◽  
The Asymmetry ◽  
The Right ◽  
Cerebral Processing

Music was played monaurally to 80 right-handed and 80 left-handed subjects. Right-handers reported more positive and less negative affect if the music was to the right ear. Left-handers reported experiencing more positive and less negative affect during music to the left ear. The hand × ear interaction was significant. The valence of emotional responses to the music seems influenced by a combination of at least two factors, (1) differences between left- and right-handers in the cerebral processing of emotional valence and (2) differences in the processing of emotional valence within each handedness group depending upon which hemisphere was initially most strongly engaged by the music. These results partially corroborate and extend the findings of previous studies in which briefer stimuli were presented tachistoscopically or dichotically. It is concluded that, while there is hemispheric asymmetry in the processing of emotional valence, the direction of the asymmetry may be associated with the handedness of the subjects.

scholarly journals Morphological and Morphometric Study of the Supratrochlear Foramen

2018 ◽  
Vol 35 (01) ◽  
pp. 54-57
Author(s):  
F.A. Silva ◽  
T.S. Silva ◽  
P.R.F.B. Souza ◽  
R.S. Reis ◽  
M.R.S. Ferreira ◽  
...  
Keyword(s):  
Distal Humerus ◽  
Distal Portion ◽  
Medullary Canal ◽  
Human Bone ◽  
Morphometric Study ◽  
Left Handed ◽  
Academic Center ◽  
Preoperative Procedures ◽  
The Mean ◽  
The Right

Introduction The supratrochlear foramen (SF) is located in the distal portion of the humerus, formed in between the coronoid fossa and the olecranon fossa. Is associated with a narrowing of the medullary canal in the distal humerus, in addition to being a phylogenetic characteristic, more common in ancient populations. The objective was to evaluate the incidence of the supratrochlear foramen, it's shape, dimensions and translucency of the septum. Materials and Methods A total of 141 humerus adults, 72 right and 69 left-handed individuals from the collection of the Human Bone of the Academic Center of Vitória-Brazil. The format was classified as oval, round, irregular and cribriform. The vertical (VD) and transversal (TD) diameter were measured and the translucency of the septum was observed. Results Of the 141 humerus, 19.8% (28) had SF 39.3% (11) on the right side and 60.7% (17) on the left side. The oval was the most recurrent, found in 39% of the cases and the translucency was identified in 78% (110) of the bones. The mean VD was 3.653 mm and 3.492 mm on the right and left sides, respectively. The mean of the TD was 4.853 mm on the right side and 5.427 mm on the left. The area averages were 19.633 ± 20.57 mm2 on the right side and 19.919 ± 19.24 mm2 on the left side. Conclusion The knowledge of SF favors the preoperative procedures of patients with fractures in the distal humerus, necessary for the surgeries in the region.

scholarly journals Individual Laterality in Ghost Crabs (Ocypode saratan) Influences Burrowing Behavior

Symmetry ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1512
Author(s):  
Reuven Yosef ◽  
Michal Daraby ◽  
Alexei Semionovikh ◽  
Jakub Z. Kosicki
Keyword(s):  
Natural Selection ◽  
Red Sea ◽  
Selection Pressure ◽  
Left Handed ◽  
Self Defense ◽  
Temporal Segregation ◽  
Ghost Crabs ◽  
Left And Right ◽  
Burrowing Behavior ◽  
The Right

Behavioral handedness is known to enhance an individual’s handling capabilities. However, the ecological advantages in brachyuran crustaceans remain unclear, despite the Ocypode species having been studied extensively. Thus, in this study, we analyzed the laterality of the endemic Red Sea ghost crab on one beach in Eilat, Israel. We successfully documented the laterality of the large cheliped in 125 crabs; in 60 (48.0%), the right cheliped was larger, and in 64 (51.2%), the left. We also observed temporal segregation between the right- and left-clawed crabs. The right-handed crabs start activity just after sunrise, while left-handed crabs appear ca. 40 min after it. Similarly, temporal segregations were also observed in the evening. The right-clawed crab activity peaked ca. 20 min before sunset, while the left-clawed crabs were active uniformly. Additionally, burrow entrances corresponded to the larger cheliped of the resident individual and is probably a self-defense-related behavior. We conclude that cheliped laterality in O. saratan populations should be considered as a bimodal trait, where left- and right-handedness is not under natural selection pressure.

Postnatal Development of a Left-Right Atrial Pressure Gradient

1956 ◽  
Vol 186 (3) ◽  
pp. 521-524 ◽  
Author(s):  
A. van Harreveld ◽  
F. E. Russell
Keyword(s):  
Left Ventricle ◽  
Pressure Gradient ◽  
Left Atrium ◽  
Postnatal Development ◽  
Right Atrial ◽  
Left And Right ◽  
The Mean ◽  
The Right ◽  
The Relationship ◽  
Equal Thickness

The mean left and right atrial pressures were measured in six groups of 10 kittens each. One group was examined between the 12th and 24th hour after birth, one group after 3 days, after 1 week, 2 weeks, 1 month and 2 months. The left and right atrial pressures were almost equal in the first group. With age an increasing left to right pressure gradient developed. In the oldest group the pressure in the left atrium was almost twice as great as in the right. Parallel with the pressure gradient a difference developed in the wall thicknesses of the left and right ventricles. At birth the ventricular walls were of about equal thickness; at age 2 months the left ventricle wall was more than twice as thick as the right. The relationship between ventricle wall thicknesses and atrial pressures is discussed.

scholarly journals Drawing with the Non-dominant Hand: Implications for the Study of Construction

1998 ◽  
Vol 25 (4) ◽  
pp. 306-309 ◽  
Author(s):  
Sherma Zacharias ◽  
Andrew Kirk
Keyword(s):  
Neurological Disease ◽  
Right Hemisphere ◽  
Normal Subjects ◽  
Elderly Subjects ◽  
Dominant Hand ◽  
Left Hand ◽  
Right Hand ◽  
Left And Right ◽  
The Right ◽  
Right And Left Hand

ABSTRACT:Background:Constructional impairment following left vs. right hemisphere damage has been extensively studied using drawing tasks. A confounding factor in these studies is that right-handed patients with left hemisphere damage (LHD) are often forced by weakness to use their non-dominant (left) hand or hemiparetic dominant hand. Qualitative differences in the drawing characteristics of left and right hand drawings by normal subjects have not previously been characterized. The present study was undertaken to determine the qualitative differences between left and right hand drawings of normal subjects.Methods:Thirty right-handed, elderly subjects without a history of neurological disease were asked to draw, from memory, seven objects using the right and left hand. Half of the subjects were randomly assigned to draw with the left hand first, and half the right hand first. Right and left hand drawings were compared using a standardized scoring system utilized in several previous studies of drawing in focal and diffuse neurological disease. Each drawing was scored on eighteen criteria. Right and left hand drawing scores were then compared using the t-test for paired samples or the Wilcoxon matched-pairs testResults:Drawings made using the left hand were found to be significantly simpler, more tremulous and of poorer overall quality than drawings made by the same subjects using the right hand.Conclusions:The deficits found in left versus right hand drawings of normals are similar to those found in patients with LHD, suggesting that much of the drawing impairment seen following LHD is due to an elementary motor disturbance related to use of the non-dominant hand.

scholarly journals Handedness and gender influence blood pressure in young healthy men and women: A pilot study

2016 ◽  
Vol 50 (1) ◽  
pp. 10-15 ◽  
Author(s):  
I Rueda ◽  
I Banegas ◽  
I Prieto ◽  
R Wangensteen ◽  
AB Segarra ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Sex Hormones ◽  
Sex Steroids ◽  
Menstrual Phase ◽  
Men And Women ◽  
Left Handed ◽  
Gender Influence ◽  
Left And Right ◽  
And Gender ◽  
The Right

AbstractObjective. The type and level of sex steroids influence blood pressure (BP). It has been suggested that functional brain asymmetries may be influenced by sex hormones. In addition, there are inter-arm differences in BP not yet related with handedness. In this study, we hypothesize a possible association between sex hormones, handedness, and inter-arm differences in blood pressure.Methods. To analyze this hypothesis, we measured BP in the left and right arm of the left and right handed adult young men and women in menstrual and ovulatory phase and calculated their mean arterial pressure (MAP).Results. Significant differences depending on sex, arm, handedness or phase of the cycle were observed. MAP was mostly higher in men than in women. Remarkably, in women, the highest levels were observed in the left handed in menstrual phase. Interestingly, the level of handedness correlated negatively with MAP measured in the left arm of right-handed women in the ovulatory phase but positively with the MAP measured in the right arm of right-handed women in the menstrual phase.Conclusions. These results may reflect an asymmetrical modulatory influence of sex hormones in BP control.

scholarly journals Growth-Related Differences in Maximum Laterotrusion and Retrusion between Children and Adults

2009 ◽  
Vol 79 (2) ◽  
pp. 265-270 ◽  
Author(s):  
Claudia A. Reicheneder ◽  
Peter Proff ◽  
Uwe Baumert ◽  
Tomas Gedrange
Keyword(s):  
Temporomandibular Joint ◽  
Null Hypothesis ◽  
Population Based ◽  
Adult Group ◽  
Population Based Study ◽  
Significant Difference ◽  
Left And Right ◽  
The Mean ◽  
The Right

Abstract Objective: To test the null hypothesis that there are no differences between children and adults in maximum laterotrusion and maximum retrusion on the right and left sides. Materials and Methods: This population-based study included 81 randomly selected children between the ages of 6 and 10 years and 67 adults. Kinematic variables were measured with the ultrasonic JMA-System for registration. Results: The mean maximum laterotrusion of the children's group (10.6 ± 1.5 mm on the left, 11.0 ± 1.7 mm on the right) was significantly smaller than that of the adult group (11.7 ± 2.0 mm on the left, 12.2 ± 1.7 mm on the right). The maximum laterotrusion of the children's group corresponded to about 90% on the left and right sides of that of the adult group. The mean maximum retrusion of the children's group was significantly bigger than that of the adult group. There, the adult values corresponded to 66.7% on the left and 50% on the right side of the children's values. No significant difference in maximum laterotrusion and retrusion was noted on the right and left sides, and no significant differences according to gender specificities were observed in either group. Conclusions: The hypothesis is rejected. In development of the temporomandibular joint, maximum laterotrusion on the right and left sides increases significantly with age, and maximum retrusion decreases significantly with age.

scholarly journals Lateral differences in maximal grip strength in Czech male tennis players aged 11 – 12 in the context of injury prevention

2019 ◽  
Vol 13 (1) ◽  
pp. 55-62
Author(s):  
Roman Kolínský ◽  
Jiří Zháněl
Keyword(s):  
Grip Strength ◽  
Effect Size ◽  
Body Height ◽  
Statistical Characteristics ◽  
Medium Effect ◽  
Dominant Hand ◽  
Tennis Players ◽  
Left Handed ◽  
Small Effect Size ◽  
The Right

The term laterality indicates the one-sided preference or functional advantage of the stronger, more accurate and coordinated limbs or organs and the brain hemisphere of a human body. In the preference process, more accurate, precise, coordinated and stronger side is chosen from the perspective of motoric functions. Among the general population is about 10-13% of left-handers and in certain sport fields this percentage may (baseball, tennis, box etc.). The left-handed dominance in tennis is considered an advantage. Due to unilateral load, there may be an excessive side-effect in strength differences in tennis and overloading of specific muscle group could lead to an injury. The aim of the research was to identify the levels of somatic and strength characteristics and assess the lateral difference in maximal grip strength of Czech elite male tennis players. The sample consisted of male tennis players, ranging in age from 11 to 12.9 years (n=186) who participated in the regular tests for Czech Tennis Association in years 2000-2018. Base anthropometrics were measured (height, weight) and maximal grip strength of both hands using the hand-held dynamometry (Grip D, Takei). Data came from normal distribution (statistically proven – chi-square test). The basic statistical characteristics were calculated (body height, M=155.08±7.98 cm; body weight, M=43.45±7.13 kg; strength of right hand: M=24.88±4.67 kp; strength of left hand: M=21.70±4.74 kp). It was found that 87.6% of the players (n=163) were right-handed and the remaining 12.4% left-handed (n=23). The assessment of the significance (Cohen´s d) between the dominant (playing) hand for the right-handed and left-handed players showed small effect size (dominant hand right: MRHR=25.11±4.41 kp, dominant hand left: MLHL=26.62±5.65 kp; d=0.30, small) in favor of the left-handed players. The difference between the dominant and the non-dominant hand showed large effect size for the right-handed (dominant hand right vs. hand left; MRHR=25.11±4.41 kp, MRHL=21.01±4.15 kp, d=0.96, large) and medium effect size for the left-handed players (dominant hand left vs. hand right; MLHL=26.62±5.65 kp, MLHR=23.24±5.98 kp, d=0.58, medium). The results showed that the value of 15 % level of strength laterality between dominant and non-dominant hand was exceeded for the right-handed (55.83 %) and left-handed (43.48%) groups ergo the exceeded value could be a cause of injuries. Because of this signals attention should be given during training process for optimizing the required load.

Cerebral Lateralization of Global-Local Processing in Left- and Right-Handed People

2005 ◽  
Vol 100 (3) ◽  
pp. 734-742 ◽  
Author(s):  
Mohammad Ali Goodarzi ◽  
Mohammad Reza Taghavi ◽  
Mohammad Reza Zoughi
Keyword(s):  
Visual Field ◽  
Left Visual Field ◽  
Right Hemisphere ◽  
Local Processing ◽  
Cerebral Lateralization ◽  
Left Handed ◽  
Left And Right ◽  
The Right ◽  
Paradigm Analysis ◽  
Local Superiority

Cerebral lateralization of global-local processing of 70 left-handed and 70 right-handed students was compared using a computerized global-local task in a half-visual field paradigm. Analysis showed that left-handed individuals were slower than right-handed individuals in processing Globally Directed stimuli presented to the left visual field (right hemisphere). In addition, left-handed individuals showed smaller local superiority in the left hemisphere to the right-handed individuals. These findings are more consistent with Levy's prediction of spatial inferiority of left-handed individuals than Geschwind and Galaburda's or Annett's hypotheses.

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