scholarly journals Are the Kinetics and Kinematics of the Surf Pop-Up Related to the Anthropometric Characteristics of the Surfer?

Sensors ◽  
2021 ◽  
Vol 21 (5) ◽  
pp. 1783
Author(s):  
Márcio Borgonovo-Santos ◽  
Thiago Telles ◽  
Jeff Nessler ◽  
Marcelo Peduzzi de Castro ◽  
Ricardo J. Fernandes ◽  
...  
Keyword(s):  
Total Duration ◽  
Peak Force ◽  
Performance Variables ◽  
Arm Span ◽  
Anthropometric Characteristics ◽  
Reaction Forces ◽  
The Impact ◽  
Force Profiles ◽  
3D Motion Capture ◽  
Push Up

The surf pop-up is a unique and challenging skill, critical to successful surfing. Hypothesizing that anthropometric characteristics of surfers influence the pop-up performance, we aimed to measure kinematics and ground-reaction forces (GRF) during a simulated pop-up motion, and to relate these variables with anthropometric characteristics. Twenty-three male surfers (age: 28.4 ± 10.1 years old; body mass: 68.3 ± 10.8 kg; height: 1.73 ± 0.07 m; time of practice: 12.4 ± 8.9 years; arm-span: 1.75 ± 8.9 m) perform a simulated pop-up in the laboratory, while GRF and 3D motion-capture data were acquired. The duration of the pop-up was 1.20 ± 0.19 s (60% push-up and 40% reaching/landing phase). During the push-up, the hands were placed 0.46 ± 0.05 m apart and generated a relative total peak-force of 0.99 ± 0.10 N/Weight, with symmetrical impulse of 0.30 ± 0.05 N·s/Weight for the dominant and 0.29 ± 0.07 N·s/Weight for the nondominant hand. Elbow angles were not different during the peak force application (110 ± 18° vs. 112 ± 18°, respectively) of the push-up phase. During the landing phase, the feet were placed 0.63 ± 0.10 m apart and generated a relative peak force of 1.63 ± 0.18 N/Weight. The impact force during landing was applied unevenly between the rear foot (28%) and the front foot (72%). In conclusion, most anthropometric-related variables showed no relationship with performance variables, with the exception of an inverse relationship between muscle mass and pop-up total duration. We also observed no differences in upper- and lower-body kinematics between the dominant vs. nondominant hands and among surfers who preferred a regular vs. “goofy-foot” stance. Finally, the force profiles between hands were similar and symmetric, while the lower extremities during the reaching phase were different, with the front foot applying greater force than that of the rear foot.

Footwear and Elevated Heel Influence On Barbell Back Squat: a Review

2021 ◽  
Author(s):  
Aaron Michael Pangan ◽  
Matthew J Leineweber
Keyword(s):  
Ground Reaction Forces ◽  
Specific Effects ◽  
Back Squat ◽  
Running Shoes ◽  
Different Types ◽  
Reaction Forces ◽  
Joint Loads ◽  
The Impact ◽  
Kinematics And Kinetics ◽  
Full Body

Abstract The back squat is one of the most effective exercises in strengthening the muscles of the lower extremity. Understanding the impact of footwear has on the biomechanics is imperative for maximizing the exercise training potential, preventing injury, and rehabilitating from injury. This review focuses on how different types of footwear affect the full-body kinematics, joint loads, muscle activity, and ground reaction forces in athletes of varying experience performing the weighted back squat. The literature search was conducted using three databases, and fourteen full-text articles were ultimately included in the review. The majority of these studies demonstrated that the choice of footwear directly impacts kinematics and kinetics. Weightlifting shoes were shown to decrease trunk lean and generate more plantarflexion relative to running shoes and barefoot lifting. Elevating the heel through the use of external squat wedges is popular clinical exercise during rehabilitation and was shown to provide similar effects to WLS. Additional research with a broader array of populations, particularly novice and female weightlifters, should be conducted to generalize the research results to non-athlete populations. Further work is also needed to characterize the specific effects of sole stiffness and heel elevation height on squatting mechanics.

Hydrodynamic Сonditions of the Bakalskaya Spit Degradation (Western Crimea) over the Past 30 Years

2021 ◽  
Vol 37 (3) ◽  
Author(s):  
B. V. Divinsky ◽  
R. D. Kosyan ◽  
◽  
Keyword(s):  
Discriminant Analysis ◽  
Coastal Zone ◽  
Satellite Images ◽  
Wind Waves ◽  
Total Duration ◽  
Wave Model ◽  
Statistical Characteristics ◽  
Wave Impact ◽  
Annual Variability ◽  
The Impact

Purpose. The paper is aimed at studying the morphodynamic features of the Bakalskaya Spit evolution being influenced by the sea wind waves and swell, namely assessment of inter-annual variations in the alluvial (erosion) areas of the Bakalskaya Spit coastline, analysis of inter-annual variability of the wind wave parameters, determination of the surface wave characteristics (or a combination of a few ones) responsible for the processes of the bottom material erosion or accumulation in the coastal zone. Methods and Results. Based on the analysis of satellite images for 1984–2016, the areas of the bottom material accumulation or erosion of the Bakalskaya Spit coastline were determined. Application of the spectral wave model permitted to obtain time series of the main parameters of wind waves and swell (significant wave heights and propagation directions) in the Bakalskaya Spit coastal zone with the 1 hr time resolution for the period from 1984 to 2016. The characteristics of surface waves responsible for the coastline deformation were revealed using the discriminant analysis. Conclusions. Analysis of satellite images of the spit made it possible to distinguish three periods in the history of the Bakalskaya Spit evolution: 1985–1997, 1998–2007 and 2007–2016. The first period was characterized by relative stability. The strongest erosion took place in 1998; after that the alluvial and erosion cases alternated for 10 years weakly tending to general erosion that constituted the second period. The third one that began in 2007 can be defined as the period of spit degradation accompanied by the irreversible loss of beach material. The basic parameters conditioning hydrodynamics of the Bakalskaya Spit water area are: total duration of storms; average and maximum values of significant heights of wind waves and swell. Statistical characteristics of the wind waves’ parameters are of a fairly strong inter-annual variability. According to the average and maximum indices, the wind waves directed close to the normal to the coastline (WSW and WNW) are the most developed. The applied discriminant analysis permitted to draw a statistically reliable conclusion that the direction of the final (average annual) wave impact on the coastal zone, conditioning the processes of sand accumulation or erosion was set by the waves directed to NNW, at that the swell contribution was dominant. The impact degree is conditioned by strong storms with the directions close to the normal to the coastline, namely, the WSW ones

Characteristics of Eight Irish Dance LandingsConsiderations for Training and Overuse Injury Prevention

2021 ◽  
Vol 25 (1) ◽  
pp. 30-37
Author(s):  
Sarah Klopp Christensen ◽  
Aaron Wayne Johnson ◽  
Natalie Van Wagoner ◽  
Taryn E. Corey ◽  
Matthew S. McClung ◽  
...  
Keyword(s):  
Large Range ◽  
Force Plate ◽  
Three Dimensional ◽  
The Body ◽  
Peak Force ◽  
Warm Up ◽  
Dance Training ◽  
Rise Rate ◽  
Dance Movements ◽  
Reaction Forces

Irish dance has evolved in aesthetics that lead to greater physical demands on dancers' bodies. Irish dancers must land from difficult moves without letting their knees bend or heels touch the ground, causing large forces to be absorbed by the body. The majority of injuries incurred by Irish dancers are due to overuse (79.6%). The purpose of this study was to determine loads on the body of female Irish dancers, including peak force, rise rate of force, and impulse, in eight common Irish hard shoe and soft shoe dance movements. It was hypothesized that these movements would produce different ground reac- tion force (GRF) characteristics. Sixteen female Irish dancers were recruited from the three highest competitive levels. Each performed a warm-up, reviewed the eight movements, and then performed each movement three times on a force plate, four in soft shoes and four in hard shoes. Ground reaction forces were measured using a three-dimensional force plate recording at 1,000 Hz. Peak force, rise rate, and vertical impulse were calculated. Peak forces normalized by each dancer's body weight for each of these variables were significantly different between move- ments and shoe types [F(15, 15)= 65.4, p < 0.01; F(15, 15) = 65.0, p < 0.01; and F(15, 15) = 67.4, p < 0.01, respectively]. The variable years of experience was not correlated with peak force, rise rate, or impulse (p > 0.40). It is concluded that there was a large range in GRF characteristics among the eight movements studied. Understanding the force of each dance step will allow instructors to develop training routines that help dancers adapt gradually to the high forces experienced in Irish dance training and competitions, thereby limiting the potential for overuse injuries.

scholarly journals The Acute Effects of Different Forms of Suspension Push‐Ups on Oxygen Consumption, Salivary Testosterone and Cortisol and Isometric Strength

2018 ◽  
Vol 64 (1) ◽  
pp. 77-85 ◽  
Author(s):  
David Bellar ◽  
Cory Etheredge ◽  
Lawrence W. Judge
Keyword(s):  
Oxygen Consumption ◽  
Repeated Measures ◽  
Bench Press ◽  
Body Height ◽  
Isometric Strength ◽  
Exercise Session ◽  
Acute Effects ◽  
Hands And Feet ◽  
The Impact ◽  
Push Up

Abstract Suspension exercise systems are being used in strength and conditioning facilities, fitness centers, rehabilitation centers and home gyms. Though some evidence exists regarding the impact of training with these systems, more work is needed for a better understanding. The purpose of the present investigation was to examine the acute effects of an exercise session with 2 (hands only) and 4 straps (hands and feet) in the push-up exercise compared to a work-matched bench press exercise session. The participants for this repeated measures, cross-over investigation were 18 healthy college-aged males (age: 24.8 ± 3.5 yrs, body mass: 81.8 ± 7.8 kg, body height: 178.9 ± 4.5 cm). The conditions were 6 sets of 10 repetitions of suspension push-ups using two straps (DUAL) for the hands, fours straps (QUAD) for hands and feet and a traditional bench press exercise matched to the average resistance during the suspension push-up. The participants performed all repetitions at a controlled cadence. Expired gases, and heart rate were monitored continuously during the exercise session. Pre and post exercise saliva samples were collected to quantify changes in testosterone and cortisol. Upper body isometric strength tests ( UBIST) were performed (Post, 1 hr, 24 hr, 48 hr) to evaluate changes in force production during recovery. Data analysis via repeated measures ANOVA revealed a significant trend for increased oxygen consumption in the QUAD condition compared to the bench press (p = 0.019). Additionally, both suspension conditions resulted in a reduced respiratory exchange ratio as compared to the bench press (p < 0.05). A significant main effect was noted for time in all conditions regarding isometric strength (p < 0.001), but no differences between conditions were revealed. Testosterone and cortisol responses did not differ between conditions. Based upon these data, it appears that when matched for work, suspension exercise results in equivalent reductions in muscle force, but greater oxygen consumption compared to isotonic exercise.

Cerebral oxygen and microdialysis monitoring during aneurysm surgery: effects of blood pressure, cerebrospinal fluid drainage, and temporary clipping on infarction

2002 ◽  
Vol 96 (6) ◽  
pp. 1013-1019 ◽  
Author(s):  
Rupert Kett-White ◽  
Peter J. Hutchinson ◽  
Pippa G. Al-Rawi ◽  
Marek Czosnyka ◽  
Arun K. Gupta ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Cerebrospinal Fluid ◽  
Brain Tissue ◽  
Total Duration ◽  
Wilcoxon Test ◽  
Fisher Exact Test ◽  
Content Type ◽  
The Impact ◽  
Temporary Clipping ◽  
Fine Print

Object. The aim of this study was to investigate potential episodes of cerebral ischemia during surgery for large and complicated aneurysms, by examining the effects of arterial temporary clipping and the impact of confounding variables such as blood pressure and cerebrospinal fluid (CSF) drainage. Methods. Brain tissue PO2, PCO2, and pH, as well as temperature and extracellular glucose, lactate, pyruvate, and glutamate were monitored in 46 patients by using multiparameter sensors and microdialysis. Baseline data showed that brain tissue PO2 decreased significantly, below a mean arterial pressure (MAP) threshold of 70 mm Hg. Further evidence of its relationship with cerebral perfusion pressure was shown by an increase in mean brain tissue PO2 after drainage of CSF from the basal cisterns (Wilcoxon test, p < 0.01). Temporary clipping was required in 31 patients, with a mean total duration of 14 minutes (range 3–52 minutes), causing brain tissue PO2 to decrease and brain tissue PCO2 to increase (Wilcoxon test, p < 0.01). In patients in whom no subsequent infarction developed in the monitored region, brain tissue PO2 fell to 11 mm Hg (95% confidence interval 8–14 mm Hg). A brain tissue PO2 level below 8 mm Hg for 30 minutes was associated with infarction in any region (p < 0.05 according to the Fisher exact test); other parameters were not predictive of infarction. Intermittent occlusions of less than 30 minutes in total had little effect on extracellular chemistry. Large glutamate increases were only seen in two patients, in both of whom brain tissue PO2 during occlusion was continuously lower than 8 mm Hg for longer than 38 minutes. Conclusions. The brain tissue PO2 decreases with hypotension, and, when it is below 8 mm Hg for longer than 30 minutes during temporary clipping, it is associated with increasing extracellular glutamate levels and cerebral infarction.

The Impact of Performance Variables on Industry in K-Economy

2013 ◽  
Vol 64 (2) ◽  
Author(s):  
Muhammad Jawad Iqbal ◽  
Ibn-e- Hassan
Keyword(s):  
Knowledge Economy ◽  
Structural Equation ◽  
Strong Relationship ◽  
Equation Modeling ◽  
Survey Questionnaire ◽  
Performance Variables ◽  
Complementary Resources ◽  
The Impact ◽  
Associated Variables

In the knowledge economy, companies are thought to be the experts who develop innovative product or service as per demand and then market it to generate the revenue. The role of industry in a knowledge economy is to search and to promote inter-organizational collaborations for learning and to search linkages to arrange for complementary resources. These interactions improve the performance of industry in the knowledge economy. This research has been conducted to find out the impact of industry associated variables that significantly influence the performance of knowledge economy. Important attributes have therefore, been identified from the studies conducted in the field of knowledge economy. Influence of identified attributes on industry has been measured using structural equation modeling (SEM) technique. Data has been collected using survey questionnaire. Findings of the study confirm that there exist a strong relationship among the industry and it’s identified variables that collectively influence the performance of industry in the knowledge economy.

scholarly journals Hybrid Closed-Loop System Achieves Optimal Perioperative Glycemia in a Boy With Type 1 Diabetes: A Case Report

2021 ◽  
Vol 9 ◽  
Author(s):  
Jesus Dominguez-Riscart ◽  
Nuria Buero-Fernandez ◽  
Ana Garcia-Zarzuela ◽  
Fernando A. Marmolejo-Franco ◽  
Ana C. Perez-Guerrero ◽  
...  
Keyword(s):  
Type 1 Diabetes ◽  
Blood Glucose ◽  
Insulin Infusion ◽  
Closed Loop ◽  
Total Duration ◽  
Blood Glucose Monitoring ◽  
Medical Team ◽  
The Family ◽  
The Impact

The goal in type 1 diabetes (T1D) therapy is to maintain optimal glycemic control under any circumstance. Diabetes technology is in continuous development to achieve this goal. The most advanced Food and Drug Administration- and European Medicines Agency-approved devices are hybrid closed-loop (HCL) systems, which deliver insulin subcutaneously in response to glucose levels according to an automated algorithm. T1D is frequently encountered in the perioperative period. The latest international guidelines for the management of children with diabetes undergoing surgery include specific adjustments to the patient's insulin therapy, hourly blood glucose monitoring, and intravenous (IV) insulin infusion. However, these guidelines were published while the HCL systems were still marginal. We present a case of a 9-year-old boy with long-standing T1D, under HCL system therapy for the last 9 months, and needing surgery for an appendectomy. We agreed with the family, the surgical team, and the anesthesiologists to continue HCL insulin infusion, without further adjustments, hourly blood glucose checks or IV insulin, while monitoring closely. The HCL system was able to keep glycemia within range for the total duration of the overnight fast, the surgery, and the initial recovery, without any external intervention or correction bolus. This is, to the best of our knowledge, the first reported pediatric case to undergo major surgery using a HCL system, and the results were absolutely satisfactory for the patient, his family, and the medical team. We believe that technology is ripe enough to advocate for a “take your pump to surgery” message, minimizing the impact and our interventions. The medical team may discuss this possibility with the family and patients.

scholarly journals CONDITIONALITY OF PRODUCTIVE LONGEVITY AND LIFELONG PRODUCTIVITY OF COWS OF BLACK-WHITE BREED BY GENETIC FACTORS

2017 ◽  
Vol 53 ◽  
pp. 222-227
Author(s):  
T. M. Komendant
Keyword(s):  
Milk Yield ◽  
Milk Fat ◽  
Total Duration ◽  
Statistical Processing ◽  
Lactation Period ◽  
Milk Productivity ◽  
Holstein Breed ◽  
Long Period ◽  
The Impact ◽  
Economic Use

Objective: to study the dependence of productive longevity of cows of black and motley breed on genetically determined factors - linearity and bloodiness in Holstein breed. Methods: zootechnical, biological, statistical. The materials of the studies were pedigree cards of cows  and bulls, bull catalogs, zootechnical reports on pedigree work with the herd, the cattle base of the Grodno region, and also registers of rearing and rearing of the litter. To study the effect on the longevity of cows and their lifelong productivity of the "linear accessory" factor, all animals that were eliminated in 2006-2014 were divided into groups according to the lines: Adema 25437, Annas Adema 30587, Vis Eidial 933122, Montvik Chiftein 95679, Nico 31652 , Pabst Governera 882933, Reflection Sovering 198998, S. Sensation 1267271, Hiltes Adema 37910. Depending on the bloodiness of the Holstein breed, the animals were divided into four groups: I - up to 25% of Holstein genes, II- 25,0 – 49,9% of the genes of the Holstein genus, III - Holstein blood 50% and more, IV - purebred black-motley cows. Indicators of milk productivity (life-time milk yield (kg) and lifetime yield of milk fat (kg), milk yield for 1 day of lactation (kg), total duration of the lactation period (days) were studied in the experimental animals, and the duration of economic use (lactations). Main results. The results obtained during the statistical processing of data indicate that the cows belonging to the Pabst Governera line 882933 differed in the longest period of economic use among the abandoned animals. Duration of use in animals of this line was 8.43 lactations, which is more than for cows of other lines at 1,72-6,67 lactation. It should be noted that cows belonging to the Adem 25437 lines (6,71 lactations) and S. Sensation 1267271 (5,49 lactations) were also characterized by a rather long period of economic use. Due to the long period of use of the cow, the Pabst Governera line 882933 had the highest indicator of lifelong milk yield – 51535,58 kg of milk and the yield of milk fat – 1914,03. But as for milk for one day of lactation, here the leadership belonged to individuals belonging to the line Vis Eidial 933122 and amounted to 21,19 kg of milk per day. Also, a fairly high indicator of milk yield for one day of lactation was observed in animals belonging to the line Montvik Chiftain 95679 – 21,02 kg of milk. As a result of the research it was found that the largest term of economic use was characterized by low-breed hybrids with Holstein breed (up to 25%) – 3,63 lactations. This group of animals exceeded the individuals of the remaining groups by 0,21-0,76 lactations. It is worth noting that purebred black-motley individuals also differed by a long period of productive use – 3,42 lactations. Conclusions. Analysis of the impact on productive longevity and indicators of lifetime productivity of the "linearity" factor among abandoned animals in the "Progress-Vertelishki" made it possible to establish the existence of significant differences in the duration of economic use of cows of different linear affiliation. Cows of the Pabst Governera line 882933 – 8,43 lactations, 51535,58 kg of milk and 1914,03 kg of milk fat were distinguished by the greatest period of productive longevity, and also by the highest milk yield and milk fat content. It was established that the crossing of black and white cattle with Holstein breed positively influenced the productive longevity of animals, but on condition that the blood on the improving rock did not exceed 25%. Low-breed hybrids with Holstein breed exceeded the animals of other groups by the duration of their economic use by 0,21-0,76 lactations. Thus, we recommend breeding cows of black and motley breeds in the "Progress-Vertelishki", taking into account the impact on productive longevity and milk productivity of such factors as linearity and bloodiness in Holstein breed.

scholarly journals The impact of some morphological and motor characteristics in short distance running

2021 ◽  
Vol 11 (6) ◽  
pp. 109-119
Author(s):  
Q. Ramabaja ◽  
N. Rashiti ◽  
M. Shkodra ◽  
L. Ramadani
Keyword(s):  
Physical Education ◽  
Motor Skills ◽  
Short Distance ◽  
Morphological Development ◽  
Strong Impact ◽  
Distance Running ◽  
Anthropometric Parameters ◽  
Long Distance ◽  
Anthropometric Characteristics ◽  
The Impact

The knowledge of morphological development and their impact on motor skills in short-distance athletes should be one of the main concerns of athletics coaches, because any scientific research in the field of physical culture and sports is about proving the development and evaluation of anthropological characteristics which are responsible for achieving success in athletics. The purpose of this paper is to confirm the impact of some anthropometric characteristics in the execution of running speeds on short distances, specifically in running at 100, 200 and 400 meters to students aged 18 ± 6 years of the Faculty of Physical Education and Sports in Prishtina. The sample of this research has included a total of 60 students aged 18 years of the Faculty of Physical Education and Sports in Prishtina. The measurements were executed during September in the hall of the Faculty, while the 100, 200, and 400 meter runs in the stadium "Fadil Vokrri" Prishtina. The only condition that was used during the determination of the sample was: that the students are involved in regular physical education classes (and on the day of the measurement be healthy, without the flu, cold or other symptoms). The variables which are applied in this research have been 8 anthropometric variables and 3 motor-specific variables. The results obtained after their processing indicate that the impact of anthropometric variables is higher in running at 100, 200 and 400 meters. Short distance running and long distance running reduces the impact of anthropometric parameters whereas the influence of metabolic factors of energy production is increased.  These results were also confirmed using regression analysis, so that groups of predictors of anthropometric characteristics, specific motor skills that statistically significantly influenced each variable of individual criteria. The world records below the 10-second limit, in the 100 m, near the 9-meter limit, show not only the high level of sports, but also the strong impact on the growth, especially of strength indicators, speed-strength, explosive force, as main and applied motor skills in sports and athlete’s everyday life.

The Effect of Corporate Sustainability Practices on Financial Performance

2019 ◽  
pp. 52-70 ◽  
Author(s):  
Ibrahim Yasar Gok ◽  
Ozan Ozdemir ◽  
Bugra Unlu
Keyword(s):  
Financial Performance ◽  
Manufacturing Industry ◽  
Corporate Sustainability ◽  
Control Sample ◽  
Corporate Financial Performance ◽  
Performance Variables ◽  
Sustainability Practices ◽  
The Impact ◽  
Positive Effect ◽  
Better Than

In this chapter, the impact of corporate sustainability practices (CSP) on corporate financial performance (CFP) is investigated in terms of Turkish manufacturing industry. In this context, 16 sustainable companies vs. 21 control companies in 2016 and 16 sustainable companies vs. 24 control companies in 2017 are examined. Thirty-seven financial performance variables within seven groups are used, and non-parametric Mann-Whitney U test is applied. In 2016, four out of seven significant variables point out that sustainable companies perform better than control sample; however, in 2017, three out of four significant variables indicate the opposite. Therefore, the results are mixed, and it is concluded that implementing environmental, social, and governance (ESG) criteria do not have a noticeable positive effect on financial performances of manufacturing industry companies, at least in the short-term.

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