BIOMECHANICAL ANALYSIS OF THE PHASES OF A PENALTY CORNER IN FIELD HOCKEY

2020 ◽  
Vol 8 (4) ◽  
pp. 67-77
Author(s):  
Radivoj Vasiljev ◽  
Aida Hubbatullina ◽  
Igor Povelkin ◽  
Radik Yakupov ◽  
Irina Vasiljevа
Keyword(s):  
Pressure Distribution ◽  
Center Of Pressure ◽  
Body Motion ◽  
Biomechanical Analysis ◽  
Field Hockey ◽  
Ideal Model ◽  
Supporting Surface ◽  
Starting Position ◽  
Research Problems ◽  
The Right

The research purpose was to provide a biomechanical analysis of penalty corner striking techniques in field hockey. Research problems. 1) To identify the boundary phases of a penalty corner; 2) To determine the mechanism of pressure distribution under the feet; 3) To identify the characteristics of an ideal model of spatial-temporal motion of the projection of the center of pressure on the supporting surface when executing a penalty corner. Methods: literature review, biomechanical analysis with the use of a podometric platform, and mathematical statistics. Results. The results of a biomechanical analysis enabled us to register the parameters of pressure distribution under a foot during a penalty corner, and to identify boundary and spatial-temporal phases. We revealed 3 periods in the movement structure: preparation, implementation, and completion. We revealed 5 movement phases: #1 Preparation, #2 Adjustment to a starting position, #3 Start of a stroke, #4 Stroke, and #5 Completion. We identified the values of pressure under a foot in each of the phases of penalty corner and the bio-mechanism of its change and regulation when during penalty corner execution. Therefore, for each phase, pressure changes under the right (R) and left (L) feet from the percentage of body weight were arranged. The arrangement is as follows: #1 – Preparation (R – 72; L – 28%), #2 Adjustment to a starting position (R – 93; L – 7%), #3 Start of a stroke (R – 17; L – 83%), # 4 Completion of a stroke (R – 16; L – 84%), and # 5 – Stick and body motion after a stroke (R-1: L-99%). We identified the characteristics of the ideal model of spatial-temporal motion of the projection of the center of pressure on the supporting surface when executing a penalty corner. We revealed that each phase took a certain time period during the stroke execution: #1 – Preparation (35%), #2 Adjustment to a starting position (22%), #3 Start of a stroke (26%), #4 Completion of a stroke (4%), and #5 Stick and body motion after a stroke (13%). Conclusion. The research findings can enable coaches and athletes to understand the characteristics of an ideal model of the stroke execution, and to get aware of various tools available for its technical support.

scholarly journals The Design and Simulation of a 16-Sensors Plantar Pressure Insole Layout for Different Applications: From Sports to Clinics, a Pilot Study

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1450
Author(s):  
Alfredo Ciniglio ◽  
Annamaria Guiotto ◽  
Fabiola Spolaor ◽  
Zimi Sawacha
Keyword(s):  
Pressure Distribution ◽  
Plantar Pressure ◽  
Center Of Pressure ◽  
Reaction Force ◽  
Weight Lifting ◽  
Lower Limbs ◽  
Plantar Pressure Distribution ◽  
Drop Landing ◽  
Mean Pressure ◽  
Footwear Design

The quantification of plantar pressure distribution is widely done in the diagnosis of lower limbs deformities, gait analysis, footwear design, and sport applications. To date, a number of pressure insole layouts have been proposed, with different configurations according to their applications. The goal of this study is to assess the validity of a 16-sensors (1.5 × 1.5 cm) pressure insole to detect plantar pressure distribution during different tasks in the clinic and sport domains. The data of 39 healthy adults, acquired with a Pedar-X® system (Novel GmbH, Munich, Germany) during walking, weight lifting, and drop landing, were used to simulate the insole. The sensors were distributed by considering the location of the peak pressure on all trials: 4 on the hindfoot, 3 on the midfoot, and 9 on the forefoot. The following variables were computed with both systems and compared by estimating the Root Mean Square Error (RMSE): Peak/Mean Pressure, Ground Reaction Force (GRF), Center of Pressure (COP), the distance between COP and the origin, the Contact Area. The lowest (0.61%) and highest (82.4%) RMSE values were detected during gait on the medial-lateral COP and the GRF, respectively. This approach could be used for testing different layouts on various applications prior to production.

Feet Plantar Pressure Distribution Among Female School Teachers

2020 ◽  
Author(s):  
Ayuni Nabilah Alias ◽  
Karmegam Karuppiah ◽  
Vivien How ◽  
Velu Perumal
Keyword(s):  
Pressure Distribution ◽  
Pressure Measurement ◽  
Plantar Pressure ◽  
Significant Finding ◽  
School Teachers ◽  
Plantar Pressure Distribution ◽  
Starting Point ◽  
The Right

Abstract Background: Plantar pressure distribution has been recognized as a significant finding to associate with various feet conditions. Objectives: To determine the feet plantar pressure distribution among female school teachers; Methods: This research consisted of 124 female school teachers. Respondents was asked to walk at a regular pace for 10 seconds from a fixed starting point while using footwear pressure insole device and pressure measurement was recorded.; Results: The findings show that lateral heel exerted the most pressure in the right and left foot (94 kPa vs 85 kPa). The second highest average of plantar pressure distribution for right foot among female school teachers was medial forefoot (67 kPa), followed by central forefoot (55 kPa), lateral forefoot (52 kPa) and lateral midfoot with 49 kPa. For the left foot, the second highest for average of plantar pressure distribution was medial forefoot (58 kPa), followed by lateral forefoot (48 kPa), and central forefoot (47 kPa) and lateral midfoot (33 kPa). The result was significant differences as the right foot often exerted greater pressure on any part of the foot than the left foot; Conclusions: The pressure plantar distribution of foot reflects the conditions of school teachers with various posture and movement.

scholarly journals Solving regularized equations in the form of polynomials

2020 ◽  
Vol 164 ◽  
pp. 02014
Author(s):  
Vera Petelina
Keyword(s):  
Differential Equations ◽  
Entire Functions ◽  
The Body ◽  
Body Motion ◽  
System Of Differential Equations ◽  
Rectangular Coordinates ◽  
Unified Algorithm ◽  
Special Points ◽  
The Right ◽  
Approximating Polynomials

The article is devoted to the determination of second-order perturbations in rectangular coordinates and components of the body motion to be under study. The main difficulty in solving this problem was the choice of a system of differential equations of perturbed motion, the coefficients of the projections of the perturbing acceleration are entire functions with respect to the independent regularizing variable. This circumstance allows constructing a unified algorithm for determining perturbations of the second and higher order in the form of finite polynomials with respect to some regularizing variables that are selected at each stage of approximation. The number of approximations is determined by the given accuracy. It is rigorously proven that the introduction of a new regularizing variable provides a representation of the right-hand sides of the system of differential equations of perturbed motion by finite polynomials. Special points are used to reduce the degree of approximating polynomials, as well as to choose regularizing variables.

Plantar Static Pressure Distribution in Healthy Individuals

2014 ◽  
Vol 7 (4) ◽  
pp. 293-297 ◽  
Author(s):  
David Pomarino ◽  
Andrea Pomarino
Keyword(s):  
Pressure Distribution ◽  
Static Pressure ◽  
Age Groups ◽  
Case Series ◽  
Load Sharing ◽  
Standing Position ◽  
Healthy Individuals ◽  
Static Pressure Distribution ◽  
Standard Values ◽  
The Right

In literature, one finds little scientific statements regarding plantar static pressure distribution in healthy individuals. Miscellaneous studies, however, characterize pathologies of feet and associate those with abnormal static or dynamic plantar load sharing. Our study reveals that healthy individuals show significant age-dependent differences in forefoot and rear foot load measured in standing position. The forefoot and rear foot load of 238 female and 193 male individuals aged between 2 and 69 years were measured. Using a pressure distribution measurement platform, the measurements were taken barefooted in standing position. Those measurements are presented as percentage of the overall load. The measurements within the age groups A1 (2-6 years), A2 (7-10 years), and A3 (11-69 years) showed significantly different forefoot loading means of the left foot (A1, 19.9%; A2, 28.2%; A3, 39.7%) and the right foot (A1, 22.6%; A2, 29.7%; A3, 39.6%). The forefoot loadings are graphically displayed as a function of the percentiles 5, 10, 25, 50, 75, 90, and 95. Forefoot loadings are referred to as “prominent” if the measured values lie off the interquartile range; if either below the percentile 10 or above 90 the loadings are referred to as “very prominent.” Our study contains significant data regarding the extent of the static load sharing of the forefoot and rear foot of healthy individuals; the data are suited for being standard values to evaluate plantar load sharing. Levels of Evidence: Diagnostic Level IV: Case series

Modulation of Spatial Orientation Processing by Mental Imagery Instructions: A MEG Study of Representational Momentum

2000 ◽  
Vol 12 (4) ◽  
pp. 569-582 ◽  
Author(s):  
Michel-Ange Amorim ◽  
Wilfried Lang ◽  
Gerald Lindinger ◽  
Dagmar Mayer ◽  
Lüder Deecke ◽  
...  
Keyword(s):  
Mental Imagery ◽  
Spatial Orientation ◽  
Visual Motion ◽  
Brain Activity ◽  
Representational Momentum ◽  
The Body ◽  
Body Motion ◽  
Body Tilt ◽  
Rotational Equilibrium ◽  
The Right

Under appropriate conditions, an observer's memory for the final position of an abruptly halted moving object is distorted in the direction of the represented motion. This phenomenon is called “representational momentum” (RM). We examined the effect of mental imagery instructions on the modulation of spatial orientation processing by testing for RM under conditions of picture versus body rotation perception and imagination. Behavioral data were gathered via classical reaction time and error measurements, whereas brain activity was recorded with the help of magnetoence-phalography (MEG). Due to the so-called inverse problem and to signal complexity, results were described at the signal level rather than with the source location modeling. Brain magnetic field strength and spatial distribution, as well as latency of P200m evoked fields were used as neurocognitive markers. A task was devised where a subject examined a rotating sea horizon as seen from a virtual boat in order to extrapolate either the picture motion or the body motion relative to the picture while the latter disappeared temporarily until a test-view was displayed as a final orientation candidate. Results suggest that perceptual interpretation and extrapolation of visual motion in the roll plane capitalize on the fronto-parietal cortical networks involving working memory processes. Extrapolation of the rotational dynamics of sea horizon revealed a RM effect simulating the role of gravity in rotational equilibrium. Modulation of the P200m component reflected spatial orientation processing and a non-voluntary detection of an incongruity between displayed and expected final orientations given the implied motion. Neuromagnetic properties of anticipatory (Contingent Magnetic Variation) and evoked (P200m) brain magnetic fields suggest, respectively, differential allocation of attentional resources by mental imagery instructions (picture vs. body tilt), and a communality of neural structures (in the right centro-parietal region) for the control of both RM and mental rotation processes. Finally, the RM of the body motion is less prone to forward shifts than that of picture motion evidencing an internalization of the implied mass of the virtual body of the observer.

scholarly journals The Effect of Uphill and Downhill Slopes on Weight Transfer, Alignment, and Shot Outcome in Golf

2018 ◽  
Vol 34 (5) ◽  
pp. 361-368 ◽  
Author(s):  
Glen M. Blenkinsop ◽  
Ying Liang ◽  
Nicholas J. Gallimore ◽  
Michael J. Hiley
Keyword(s):  
Center Of Pressure ◽  
Performance Outcomes ◽  
Computer Assisted ◽  
Ball Speed ◽  
Transfer Alignment ◽  
3 Dimensional ◽  
The Right ◽  
Weight Transfer ◽  
Kinetics Of ◽  
Kinematics And Kinetics

The aim of the study was to examine changes in weight transfer, alignment, and shot outcome during golf shots from flat, uphill, and downhill slopes. Twelve elite male golfers hit 30 shots with a 6-iron from a computer-assisted rehabilitation environment used to create 5° slopes while collecting 3-dimensional kinematics and kinetics of the swing. A launch monitor measured performance outcomes. A shift in the center of pressure was found throughout the swing when performed on a slope, with the mean position moving approximately 9% closer to the lower foot. The golfers attempted to remain perpendicular to the slope, resulting in weight transfer toward the lower foot. The golfers adopted a wider stance in the sloped conditions and moved the ball toward the higher foot at address. Ball speed was not significantly affected by the slope, but launch angle and ball spin were. As the coaching literature predicted, golfers were more likely to hit shots to the left from an uphill slope and to the right from a downhill slope. No consistent compensatory adjustments in alignment at address or azimuth were found, with the change in final shot dispersion resulting from the lateral spin of the ball.

Morphometric Characterization and Finite Element Modeling of the Physiological Tricuspid Valve

2009 ◽  
Author(s):  
Marco Stevanella ◽  
Emiliano Votta ◽  
Massimo Lemma ◽  
Carlo Antona ◽  
Alberto Redaelli
Keyword(s):  
Finite Element ◽  
Tricuspid Valve ◽  
Heart Valves ◽  
Heart Surgery ◽  
Biomechanical Analysis ◽  
Left Heart ◽  
Mortality And Morbidity ◽  
Functional Tricuspid Regurgitation ◽  
Underlying Mechanisms ◽  
The Right

The tricuspid valve (TV) is the right atrio-ventricular valve. The most common TV disease is secondary or functional tricuspid regurgitation (FTR), an important complication of left-sided valvular heart lesions, which frequently persists after mitral and aortic valve operations. FTR is associated with high mortality and morbidity and requires surgical intervention, the preferential solution being TV repair through techniques such as annuloplasty performed during left heart surgery. However, significant residual regurgitation persists or recurs in 10% to 20% after annuloplasty, thus highlighting the incomplete understanding of the underlying mechanisms and the need for deeper insight into TV pathophysiology. At this purpose finite element models (FEMs) could be adopted, as suggested by their effective application to the biomechanical analysis of left heart valves. However, while for those several data are available regarding morphology and tissue mechanical properties, such information is missing for the TV, making it difficult to implement a FEM of the TV.

Contribution of “Folia Turistica” Journal to the Development of Research and Popularisation of Economic Knowledge in the Scope of Tourism

2019 ◽  
Vol 50 (2) ◽  
pp. 8-8
Author(s):  
Grzegorz Gołembski
Keyword(s):  
Editorial Team ◽  
Economic Knowledge ◽  
Comprehensive Collection ◽  
Research Problems ◽  
Similar Remark ◽  
Expert Analysis ◽  
Tourist Demand ◽  
The Times ◽  
The Right ◽  
Tourism Economy

Purpose. The aim of the considerations is to evaluate the contribution of scientific articles published in the “Folia Turistica” journal in the years 1990-2018 to the development of research and popularisation of economic knowledge related to management at the micro, mesoand micro-economic level. Method. For the implementation of the presented objective, scientific articles have been singled out – of all the works published in the given journal – the issues of which form part of the scope of economic sciences. Then, qualitative (expert) analysis of the content of these articles was performed in terms of the research problems undertaken in them, the methods applied for their solution and the results obtained in this manner. Attention was particularly paid to the methodological correctness of the analysed texts and their contribution to the development of economic reflection on the tourist activity of a human being – taking the state of economic knowledge appropriate for the times in which individual articles were created into account. Findings. As a result of the above procedure, more than 40 scientific articles, strictly economic in nature, published in “Folia ...” were distinguished. These articles were grouped into 6 thematic blocks, which – in general – concerned: (1) the concept of “tourism economy”, (2) macro-economic issues, (3) tourist demand and consumption, (4) tourist region, including sustainable development, (5) the competitiveness of hotel enterprises, and (6) knowledge transfer. Analysis of the content of articles included in each of these thematic blocks revealed that the works published on the pages of “Folia ...” create a broad, yet at the same time, coherent, even comprehensive collection of considerations in the field of tourism management. It is also worth noting that the authors publishing their works in the journal often undertook issues that, at the time of their publication, were innovative; a similar remark concerns the research methods used by them. Research and conclusions limitations. The assessment of articles in the field of economic sciences published in “Folia ...” is qualitative (expert), thus the formulated conclusions are characterised by subjectivism. Practical implications. The results of the analysis presented here and the conclusions drawn from them may prove to be useful for the editorial team of the “Folia Turistica” journal - indicating the right directions for undertaking initiatives related to the publishing of thematic issues with an economic profile. Originality. The article contains an analysis of existing texts. However, due to the ordering nature and the critical view of the texts mentioned in it, it is an original study – relevant to the evaluation of one of the oldest tourist journals in Poland on the development of economic reflection on spatial mobility of people.

Electric Wheelchair Controlled by Human Body Motion -Classification of Body Motion and Improvement of Control Method-

2010 ◽  
Vol 22 (4) ◽  
pp. 439-446 ◽  
Author(s):  
Sho Yokota ◽  
◽  
Hiroshi Hashimoto ◽  
Yasuhiro Ohyama ◽  
Jinhua She ◽  
...  
Keyword(s):  
Pressure Distribution ◽  
Human Body ◽  
Control Method ◽  
Body Movement ◽  
Single Point ◽  
Movement Pattern ◽  
Body Motion ◽  
Self Organizing Map ◽  
Electric Wheelchair ◽  
Wheelchair Control

This paper classifies human body movements when an electric wheelchair was controlled using a Human Body Motion Interface (HBMI) by a Self-Organizing Map (SOM) and proposes control based on classification results. The Human Body Motion Interface (HBMI) uses body movement following voluntary motion. This study focuses on electric wheelchair control as an application of the HBMI. The viability of the HBMI was confirmed using Center Of Weight (C.O.W.) from pressure distribution information on backrest in the wheelchair to control it. If body movement concentrated on a single point at C.O.W. in pressure distribution, a problem occurred because the system would recognize even different body-movement patterns as the same movement. We call body movement taking the same C.O.W. even if it has a different body-movement pattern movement confusion. We solve the movement confusion problem and enhance wheelchair control, classifying body movement using the SOM and reflecting this classification result to improve wheelchair control. Experimental results showed that movement confusion is solved and wheelchair control improved.

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