Riders’ perception of symmetrical pressure on their ischial tuberosities and rein contact tension whilst sitting on a static object

2017 ◽  
Vol 13 (1) ◽  
pp. 7-12 ◽  
Author(s):  
R. Guire ◽  
H. Mathie ◽  
M. Fisher ◽  
D. Fisher

The horse-rider system is of great interest in understanding the mechanics involved in optimising locomotor function and performance in the ridden horse. Adult riders (n=30) attending a rider conference volunteered to take part in the study. Riders were asked to mimic riding position by positioning themselves symmetrically on their seat bones (ischial tuberosities) sitting on a (Pliance) pressure mat which was placed on a static platform. Riders were also asked to mimic even rein contact using reins with gauges which were attached to a solid wall. When satisfied that they were sitting symmetrically and had an even rein contact, pressure and rein measurements were captured for 5 s and repeated three times. A paired T Test was carried out to determine differences between left and right ischial tuberosities and rein pressures. Using a static model, this study found that the riders had significantly more pressure beneath the left ischial tuberosity (mean ± standard deviation, 3.22±1.43 N/cm2) compared to the right (2.65±1.49 N/cm2) (P=0.04) and no significant differences were observed between left (6.37±2.42 N) and right rein pressure (6.38±2.66 N) (P=0.95). Whilst sitting on a static platform, differences in ischial tuberosity pressure in adult riders were observed despite these riders’ perception that their seat was symmetrically weighted. These differences observed need to be investigated further, dynamically, to determine if there is a similar trend in the ridden situation.

2021 ◽  
Vol 29 (1) ◽  
pp. 20-33
Author(s):  
Aleksandr V. Kolsanov ◽  
Sergey N. Chemidronov ◽  
Vadim D. Kornilov ◽  
Galina N. Suvorova

In modern specialized literature, there is practically no information about the shape, size and topography of one of the most important formations of the perineum - of the perineal body. Knowledge of the anatomical aspects of the structure and location of the perineal center would allow in the future to reduce the postoperative complications associated with unintentional damage. The question of the morphology of the perineal body and associated muscles in clinical practice in obstetric traumatism remains relevant. The aim of the study was to study the morphometric parameters and features of the topography of the human perineal body. The objects of the study were 50 autopsy cases of people aged 60-87 years, 25 of each sex, who died from causes not related to the pathology of the pelvic organs. In each case, the perineal body, location of its center and associated muscles were identified. Methods of classical anatomical preparation, description and statistical analysis were used in the work. As a result of the work, five forms of the perineal body were identified: cruciform, «hourglass», triangular, round, polygonal. There were also cases where it was not possible to determine the shape of the intersection of the fibers. For men, the most common triangular shape, for women - the shape of an «hourglass». In most cases in which the shape of the intersection of the fibers was determined, there were clearly identifiable tendon fibers, that is, the tendinal center of the perineal body was present. The average area of ​​the tendinal center of the perineal body in women was 0.99±0.47 cm², and in men 0.94±0.32 cm². The ratio of cases of displacement of the tendinal center towards the right or left ischial tuberosities is almost equal to 10 cases towards the right ischial tuberosity and 11 cases towards the left. When evaluating the pubo-coccygeal asymmetry, in most cases with a triangular shape, there is a sharp displacement towards the apex of the coccyx. Also, the authors found that the average area of ​​the tendinal center of the perineal body is larger in women than in men. Thus, the human perineal body has a variety of forms, according to the authors, associated not only with the embryological features of the development of the muscles of the perineum, but also with the lifestyle, a history of diseases and surgical interventions in the area of ​​the tendinal center of the perineal body.


Author(s):  
Despina Vasileva ◽  

A study about perception of a page from a textbook of Bulgarian is presented in the article. Participants in the experiment are 30 students of age 15 to 19 from high schools in Sofia. The study is realized through an eye tracking system. For the purposes of the study 8 stimuli (textbook pages) were constructed, containing the components as follows: “text”, “image”, and “diagram”. In each stimulus the quantity of the components differs. All possible pairs in a combination in the left and in the right field of view are presented in the stimuli. The goal of the research is to be examined the fixation of the gaze on each elements of a textbook page. To assess the characteristic of the gaze was calculated the number of saccades in the left and right visual field of the slides. The data are organized in spreadsheets. Statistical analysis is performed in two-group t-test (two samples with different variances). Mean number of saccades, standard deviation, standard error, critical ratio are calculated.


1981 ◽  
Vol 240 (6) ◽  
pp. H896-H900
Author(s):  
W. P. Santamore ◽  
R. Carey ◽  
D. Goodrich ◽  
A. A. Bove

To better understand biventricular mechanics, an algorithm was developed to simultaneously calculate right and left ventricular volumes from randomly placed subendocardial radiopaque markers. Mathematically, the ventricle is represented as a stack of circular discs. The radius R of each disc is calculated as the distance from the subendocardial radiopaque marker to a computer generated base-to-apex line, and the height H of each disc is determined by the projected distance between radiopaque markers along the base-to-apex line. Accordingly, the volume (V) is calculated as V = pi . sigma Hi . Ri2. The validity of this algorithm was tested on 10 canine left ventricular casts, on 10 human right ventricular casts, and in five experiments. For the left ventricle, the regression line between the casts (VT) and calculated (VC) volumes was VC = 0.55 VT + 6.6, with r = 0.95, standard error of estimate (Sy) = 1.9 ml, and the standard deviation of percent error = 12.6%. For the right ventricle, VC = 1.75 VT = 42.5, with r = 0.86, Sy = 16.2 ml, and the standard deviation of percent error = 24.8%. In five animal experiments, radiopaque markers were implanted into the endocardium of the left and right ventricles and comparisons were made between angiographic- and marker-determined ventricular volumes. For the five experiments, the mean correlation coefficient, relating the marker volumes to the angiographic volumes, were 0.92 +/- 0.01 for the left ventricle and 0.89 +/- 0.02 for the right ventricle. The results, which are similar to other volume-determination methods, indicate that this method can be applied to determine right and left ventricular volume. Once implanted, fluoroscopy of these markers provides a noninvasive means of calculating ventricular volume.


2014 ◽  
Vol 25 (05) ◽  
pp. 441-448 ◽  
Author(s):  
Defne Abur ◽  
Nicholas J. Horton ◽  
Susan E. Voss

Background: Power reflectance measurements are an active area of research related to the development of noninvasive middle-ear assessment methods. There are limited data related to test-retest measures of power reflectance. Purpose: This study investigates test-retest features of power reflectance, including comparisons of intrasubject versus intersubject variability and how ear-canal measurement location affects measurements. Research Design: Repeated measurements of power reflectance were made at about weekly intervals. The subjects returned for four to eight sessions. Measurements were made at three ear-canal locations: a deep insertion depth (with a foam plug flush at the entrance to the ear canal) and both 3 and 6 mm more lateral to this deep insertion. Study Sample: Repeated measurements on seven subjects are reported. All subjects were female, between 19 and 22 yr old, and enrolled at an undergraduate women’s college. Data Collection and Analysis: Measurements on both the right and left ears were made at three ear-canal locations during each of four to eight measurement sessions. Random-effects regression models were used for the analysis to account for repeated measures within subjects. The mean power reflectance for each position over all sessions was calculated for each subject. Results: The comparison of power reflectance from the left and right ears of an individual subject varied greatly over the seven subjects; the difference between the power reflectance measured on the left and that measured on the right was compared at 248 frequencies, and depending on the subject, the percentage of tested frequencies for which the left and right ears differed significantly ranged from 10% to 93% (some with left values greater than right values and others with the opposite pattern). Although the individual subjects showed left-right differences, the overall population generally did not show significant differences between the left and right ears. The mean power reflectance for each measurement position over all sessions depended on the location of the probe in the ear for frequencies of less than 1000 Hz. The standard deviation between subjects' mean power reflectance after controlling for ear (left or right) was found to be greater than the standard deviation within the individual subject’s mean power reflectance. The intrasubject standard deviation in power reflectance was smallest at the deepest insertion depths. Conclusions: All subjects had differences in power reflectance between their left and right ears at some frequencies; the percentage of frequencies at which differences occurred varied greatly across subjects. The intrasubject standard deviations were smallest for the deepest probe insertion depths, suggesting clinical measurements should be made with as deep an insertion as practically possible to minimize variability. This deep insertion will reduce both acoustic leaks and the effect of low-frequency ear-canal losses. The within-subject standard deviations were about half the magnitude of the overall standard deviations, quantifying the extent of intrasubject versus intersubject variability.


2020 ◽  
Vol 5 (1) ◽  
pp. 14-19
Author(s):  
K Ramkumar ◽  
◽  
S. Sripriya ◽  
C. Sabarigirinathan ◽  
◽  
...  

Aim: To find sites in human temporal bone for placing longer implant Materials & Methods: Dry human skull were procured from the anatomy department. External acoustic meatus(EAM) was taken as reference point from that point five arcs of radius15mm, 20mm,25mm,30mm,35 mm were drawn over the temporal bone. The temporal bone removed from the skull and the bone is removed from the outer most point towards the EAM. The thickness of the bone at 1oClock and 4o Clock position and 8oClock and 11o Clock position over the left and right side of the temporal measured using digital Vernier calliper. The temporal bone is thicker at the 3oClock on the left and 9oClock on the right side. The thickness at the new position also measured. Result: The mean bone thickness at 15mm, 20mm, 25mm ranges from 3.92 to 12.08mm. The mean bone Thickness at the 3oclock and 9 o clock position at the distance of 20mm from EAM ranges from 8.21 to 8.50mm.The Statistical significance within the group were analysed using paired t test and found to be statistical significant at P value less than. 05. Conclusion: The external surface of temporal bone at the 3oClock on the left and 9oClock on the right side denser and thicker. The bone availability is also more favours for placing longer implant.


2020 ◽  
Vol 16 (1) ◽  
pp. 75-85 ◽  
Author(s):  
T.L. Bye ◽  
V. Lewis

Studies into horse-saddle-rider interaction demonstrate that increased vertical forces on the horse’s back are potentially damaging to the musculoskeletal system, and any practice that could lead to this warrants investigation. The contribution of the stirrups in stabilising the bodyweight of the rider, and the effect of riding without stirrups on force distribution to the horse, has yet to be fully described in the literature. The current study therefore aimed to compare saddle and stirrup forces in three conditions; sitting trot, rising trot, and sitting trot without stirrups on the riding simulator. Fourteen amateur female riders of mean age 34.6±10 years participated in the study and 20 s of data were collected for saddle and stirrup force across the three conditions. Mean and peak forces were extracted from the data for total force under the whole saddle, left and right sides of the saddle separately, left and right stirrups, and both stirrups combined. Peak vertical saddle forces were significantly higher in sitting trot without stirrups than with (P=0.011). Higher mean and peak saddle forces were seen on the right-hand side in all conditions (P<0.001) and there was an overall tendency for higher left stirrup forces in both sitting and rising trot with this being significant for peak force in sitting trot (P=0.039). The higher forces recorded when trotting without stirrups indicate that the stirrups play an important role in controlling the vertical acceleration of the rider in relation to the horse, however further studies are needed on live horses before any specific recommendations can be made regarding training practices. Asymmetrical saddle forces have a potentially negative effect on the horse and future research should also aim to identify the underlying causes of these patterns of rider asymmetry to improve both horse welfare and performance.


2020 ◽  
Vol 10 (1) ◽  
pp. 63-71
Author(s):  
Nurhaeda Abbas ◽  
Anggraini Sukmawati ◽  
Muhammad Syamsun

Today the performance measurement of Muhammadiyah Luwuk uUniversity’s performance has not formulated yet based on University’s vision and mission. It will affect the strategic steps needed and performance improvement efforts in the future.  Human resource scorecard is the right system to be applied in Muhammadiyah Luwuk University. The purpose of this study is to designed a performance measurement system at Muhammadiyah Luwuk University using the Human Resource Scorecard with four perspectives: stakeholder, academic management and kemuhammadiyaan, operational and innovation, as well as and learning. Data was analyzed by analytical hierarchy process method. This research was conducted by distributing questionnaires, focus group discussions and in-depth interview with stakeholders at Muhammadiyah Luwuk University. The results showed that there were 14 strategic objectives and 33 key performance indicators to be achieved by the priority objectives, which are: empowerment and development of faculty, increased administrative process quality, improved sound budget performance and, improvement of the relationship with stakeholders.


Author(s):  
O. I. Admakin ◽  
I. A. Solop ◽  
A. D. Oksentyuk

Relevance. The narrowing of the maxilla is one of the most common pathologies in orthodontics. Recent studies show that the narrowing is always asymmetric which is connected to the rotation of the maxilla. To choose the treatment correctly one need a calculation that reveals the asymmetry, which is impossible with using standard indexes.Purpose – to compare efficiency of indexes of Pont and Korkhause with the Kernott's method in patients with narrowing of the maxilla.Materials and methods. The study involved 35 children aged from 8 to 12 years old undergoing dental treatment in the University Children's Clinical Hospital of the First Moscow State Medical University with no comorbidities. For every patient a gypsum model was prepared and after that to carry out the biometrical calculation. In this study two indexes were used: Pont's index and Korkhause's; using this standard analysis the narrowing of the maxilla was revealed. After using Pont's Index and Korkhaus analysis all the models were calculated by the method of Kernott with Kernott's dynamic pentagon.Results. As a result of the analysis of the control diagnostic models a narrowing of the maxilla in 69% of cases (n = 24) was revealed in all cases, the deviation of the size of the dentition was asymmetric. Thus, 65% of the surveyed models showed a narrowing on the right. This narrowing was of a different severity and averaged 15 control models.Conclusions. This shows that for the biometrics of diagnostic models it is necessary to use methods that allow to estimate the width of the dentition rows on the left and on the right separately. To correct the asymmetric narrowing of the dentition, it is preferable to use non-classical expanding devices that act equally on the left and right sides separetly.


Author(s):  
Emanuela Gualdi-Russo ◽  
Natascia Rinaldo ◽  
Alba Pasini ◽  
Luciana Zaccagni

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.


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