American Journal of Sports Science and Medicine最新文献

{"title":"Soccer Passing Accuracy Differentiates Between High and Low Digit Ratio (2D:4D) Soccer Players","authors":"Muhammad Shahidul Islam, Brajanath Kundu","doi":"10.11648/J.AJSS.20200803.11","DOIUrl":"https://doi.org/10.11648/J.AJSS.20200803.11","url":null,"abstract":"The purpose of the present study was to know soccer passing accuracy performances between the national youth level soccer players possessing high digit ratio and low digit ratio (2D:4D). The study was carried out in 108 male soccer players of Bangladesh aged between 16 to 19 years for measured the digit ratio. To find out the high and low digit ratio groups of participant quartile deviation has been used. Participants belonged to 0.973 and above (N=28) were categorized into high digit ratio group and 0.942 and below (N=28) were categorized into low digit ratio group. Soccer passing accuracy performance was assessed (N=56) by using Loughborough Soccer Passing Test (LSPT). Digit ratio (2D:4D) was measured by digital vernier caliper, Mitutoyo Corporation, Japan measuring to 0.01 mm. The length of the index finger (2D) and ring finger (4D) measured in millimeters from the second metacarpophalangeal crease of the finger to the fingertip. The mean digit ratio was calculated as dividing the length of the 2D by the length of the 4D for the left and right hand one by one and then computes the mean of these two ratios. To find out the significance of differences of soccer passing accuracy between the high digit ratio and the low digit ratio groups independent t-test was used. It was observed that the mean score in soccer passing accuracy performance, i.e., LSPT Total performance (TP) of the lower digit ratio, group was a significantly better performer than that of the high digit ratio group. A higher level of fetal testosterone, characterized by lower values of the digit finger ratio (2D:4D), may be associated with a higher performance of soccer passing accuracy in multifaceted aspects including passing, dribbling, controlling, turning, decision-making, and cognition.","PeriodicalId":261831,"journal":{"name":"American Journal of Sports Science and Medicine","volume":"75 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116357545","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Alterations in Team Physical Performance and Possession in Elite Gaelic Football Competition","authors":"D. Gamble, N. Moyna, Richard McCann, D. Martin, G. McMahon, Lee Rooney, Matt Spencer, J. Bradley, A. Mccarren","doi":"10.11648/J.AJSS.20200802.13","DOIUrl":"https://doi.org/10.11648/J.AJSS.20200802.13","url":null,"abstract":"Differences in performance between winning and losing were examined in 1 elite Gaelic football team in 20 games across 2 complete competitive seasons. Possession was codified using Dartfish TeamPro software and distance covered; walking, jogging, running, and running at high and maximum speeds, was evaluated using Catapult OptimEye S5 player tracking devices. Distance covered in low intensity activity (LIA, ˂4.0 m.s-1), high intensity running (HIR, ≥4.0 m•s-1) and very high intensity running (VHIR, ≥5.5 m•s-1) was also examined along with PlayerLoad™, which represented a composite of all accelerations. Data from 53 players (n=405 files) was collated into specific match periods to facilitate a temporal analysis between the first and second halves and from quarter 1 (Q1) to quarter 4 (Q4), with significance accepted at p ≤ 0.05. Total distance and running was higher in games lost, whereas total distance, walking and LIA was higher in halves lost. Only walking was higher in quarters lost. The percentage of possession declined in halves and quarters lost. In games lost, high speed running declined in the second half. From Q1 to Q4; PlayerLoad™, total distance, jogging, high speed running, HIR and VHIR, decreased in all games combined and in games lost. Possession frequency declined in Q4 in all games and in games won. Overall, total distance was higher in games lost and physical performance declines were more pronounced when examined by match quarter compared to half and were only apparent in games lost. Similarly, reductions in possession frequency and percentage were more evident when examined by quarter or period lost, respectively. These findings can inform the prescription of conditioning and field-training strategies to mitigate the reductions in performance observed in losing and towards the end of games.","PeriodicalId":261831,"journal":{"name":"American Journal of Sports Science and Medicine","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129243749","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Biomechanical Analysis Hammer Throw: The Influence of Kinematic Parameters on the Results of Finalists World Championships","authors":"R. Pavlović","doi":"10.12691/AJSSM-8-2-1","DOIUrl":"https://doi.org/10.12691/AJSSM-8-2-1","url":null,"abstract":"Background: Hammer throw is the most complex athletic throwing discipline with a rotational trajectory and the strong action of several different forces that try to disable the projected throwing trajectory. Kinematic parameters are an important segment in the analysis of athletic disciplines, including hammer throw. Aim study: The aim of the study was to determine the influence of spatial and temporal biomechanical parameters on hammer throw results. Methods: The study was conducted on a sample of 56 male and female World Championship finalists (Berlin, 2009, Daegu, 2011, London, 2017). Multiple regression analysis was applied to determine the influence of defined kinematic parameters on the result performance of the throw. Result: The results of the male finalists confirmed the direct correlation between the starting speed (r=0.64 p=0.001), the first turn speed (r=0.47 p=0.017), the release velocity (r=0.86 p=0.000), the release of angle (r=0.37 p=0.049), and the inverse effect of the duration of the first (r=-0.40 p=0.046) and third turn (-0.46 p=0.020). The regression function of the male sample also confirmed the influence of starting speed, release of velocity (p=0.01 p<0.05) and angle of release (p=0.04 p<0.05). In the female finalists, the direct correlation is between the release of velocity (r=0.90 p=0.000), the angle of release (r=-0.62 p=0.000) and the fourth turn speed (r=0.50 p=0.002). The regression function for the female sample confirmed a high negative influence of the starting speed, while the direct influence was recorded at the release of velocity (p=0.02 p<0.05) at the given level of statistical significance of the regression function. Conclusion: The defined set of kinematic parameters had a significant impact on the result performance of male and female hammer throw finalists.","PeriodicalId":261831,"journal":{"name":"American Journal of Sports Science and Medicine","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121944682","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"OpenButterfly: Multimodal Rehabilitation Analysis of Immersive Virtual Reality for Physical Therapy","authors":"Michael Powell, Aviv Elor, M. Teodorescu, S. Kurniawan","doi":"10.12691/AJSSM-8-1-5","DOIUrl":"https://doi.org/10.12691/AJSSM-8-1-5","url":null,"abstract":"Upper limb injury often requires repetitive and long-term physical rehabilitation which can result in low adherence due to the repetitive and internally motivated nature of the exercises. Immersive Virtual Reality (iVR) systems enhanced with games can address these challenges. These systems provide a platform for adaptable sensing and analytical tools to track progress, personalize therapy, and increase long term engagement. This paper explores such a system, through an iVR-based experience for upper-extremity rehabilitation called “OpenButterfly,” where users follow movements to protect a virtual butterfly. OpenButterfly enables a dynamically controllable environment for individual exercise by utilizing motion capture, a biomechanical model of torque and angular momentum, and a biometric pipeline for brainwave, heartrate, and skin conductance analysis. We examine this experience for five adult users with varying degrees of injury over the course of eight weeks. Our results suggest that experiences like OpenButterfly provide strong platforms for long-term physical therapy engagement, analysis, and recovery. Lastly, this paper concludes with considerations for future research into adaptive iVR physio-rehabilitation.","PeriodicalId":261831,"journal":{"name":"American Journal of Sports Science and Medicine","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114615955","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Recent Trends in Physique and Motor Ability of Preschool Children-Trends After 2000 in Japan","authors":"K. Fujii, Nozomi Tanaka, Toshiro Sakai, Yuki Takeyama","doi":"10.11648/J.AJSS.20200802.12","DOIUrl":"https://doi.org/10.11648/J.AJSS.20200802.12","url":null,"abstract":"The purpose of this study was to clarify the trends since 2000 in body shape, physical strength, and motor ability in early childhood in Japan. The study subjects were kindergarten and nursery school girls (age 3–5 years old) in Aichi Prefecture, Japan. Physique (height and weight), quantitative motor ability (20 m dash, standing long jump, tennis ball throw, side step, one-leg hop, hanging from a horizontal bar, and general motor ability (jump over and under) were compared in the 1999 and 2009 school years. The results revealed that, compared with ten years earlier, height was approximately 0.9 cm shorter in 4-year-old girls and weight was approximately 0.3 kg lighter in 3- and 4-year-old girls in 2009. In physical strength and motor ability, the time for jump over and under was shorter in 3-year-olds, the number of times a rope was jumped was higher and the time hanging from a horizontal bar was longer, and the time for jump over and under was shorter in 4-year-olds. In 5-year-olds, only an increase in the number of times a rope was jumped increased. The tennis ball throw and side steps were not significantly different from 10 years earlier in any of the ages. Physique, physical strength, and motor ability improved with growth, but compared with 10 years earlier many of the items were found to decrease or remain the same in all ages.","PeriodicalId":261831,"journal":{"name":"American Journal of Sports Science and Medicine","volume":"0 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128544684","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Stem Cells: A Reformist Therapeutic Approach to Orthopaedic Sports Medicine","authors":"O. Oral, G. Nomikos, N. Nomikos","doi":"10.12691/AJSSM-8-1-3","DOIUrl":"https://doi.org/10.12691/AJSSM-8-1-3","url":null,"abstract":"Background: The aim of the research is to identify, study the effects of stem cell therapies on sports injuries and examine how stem cell therapies may benefit the healing process and improve the athletes' physical state. With an extensive literature review, the purpose of this article to investigate the true potentials of regenerative stem cell therapy and shed light on innovative ways of treatment for sports injuries. It is theorized that stem cell therapy is an efficient and effective treatment method for sports injuries. Stem cell therapy is an innovative way of treating musculoskeletal injuries to provide faster and safer treatment to athletes. As sports injuries are one of the major concerns of the athletes, stem cell therapies are quite promising with effective and safe results. It is possible to fully heal certain injuries, regain functions, and reduce symptoms. Stem cell therapy is a method that should be popularised and preferred particularly by athletes.","PeriodicalId":261831,"journal":{"name":"American Journal of Sports Science and Medicine","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132036969","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rapid Identification of Saber Steel Flexibility, Microhardness, and Chemical Composition by Analyzing Electromagnetic Signatures","authors":"L. Chen","doi":"10.11648/J.AJSS.20200802.11","DOIUrl":"https://doi.org/10.11648/J.AJSS.20200802.11","url":null,"abstract":"Modern fencing sabers are made of composite steel alloys. Although there are regulations standardizing blade dimensions and stiffness, fencers often find blades having variable flexibility and tensile strength from vendor to vendor and, occasionally, from batch to batch of production. Due to the absence of an objective test to assess blade quality, fencers often resort to testing blades with simple visual or physical whip tests. These manual blade assessments, however, are unsatisfactory due to subjective inconsistencies as well as unreliability due to similar blade weights, colors, and appearances. The ability to properly and accurately test blade quality is of utmost importance, not only for competition, but more importantly, to prevent injuries which have occurred as a result of broken blades. Traditional industrial methods of steel alloy identification involve spectrometry or machine tensile strength assessments, which are both destructive to the blade and impractical in a competition arena. We previously reported a method to use the smartphone magnetometer to differentiate fencing steel alloys. This manuscript now demonstrates the correlation between electromagnetic signatures to the flexibility, microhardness and chemical composition of steel blades.","PeriodicalId":261831,"journal":{"name":"American Journal of Sports Science and Medicine","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129132855","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Regenerative Biological Effects of Platelet-Rich Plasma (PRP) Therapy in Orthopaedic Sports Medicine","authors":"O. Oral, G. Nomikos, N. Nomikos","doi":"10.12691/AJSSM-8-1-4","DOIUrl":"https://doi.org/10.12691/AJSSM-8-1-4","url":null,"abstract":"Sports injuries may lead to severe consequences for athletes. Many athletes suffer from injuries of skeletal muscle. While these injuries may be minor, they may be quite serious [1]. An athlete needs to train on a regular basis. An injury causes her/his time to be wasted. Similarly, if the athlete is a member of a certain team, the injury affects multiple people. Platelet-rich plasma (PRP) is a quite promising technique with significant potentials. PRP is an autologous blood product used in terms of sports medicine to treat acute and chronic tendon, ligament, and muscle injuries in over 86,000 athletes in the United States on annual basis [2]. PRP is a quite promising technique with significant potentials. It is expected to accelerate the healing process of tendon and ligament related injuries. This is particularly advantageous for athletes [3].","PeriodicalId":261831,"journal":{"name":"American Journal of Sports Science and Medicine","volume":"123 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121509186","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Kinematic Analysis of Support Phase Characteristics in Women Race Walking","authors":"Dibendu Kr. Bej","doi":"10.11648/J.AJSS.20200801.14","DOIUrl":"https://doi.org/10.11648/J.AJSS.20200801.14","url":null,"abstract":"Race walking requires a great deal of effort to compete successfully which includes a unique combination of technique, extreme physical exertion and mental focus. Unlike running, race walking is composed by support phase (heel strike, mid-stance and toe off) and swing phase. The aim of this study was to analyze the association between different kinematic characteristics of support phase during race walking and walking velocity. The rules of race walking demand that no visible flight time should occur and the stance leg must be straightened from initial contact to midstance. Previous research has not examined whether these rules also have an effect on walking performance and what consequences might arise. Top ten (U-20 Girls) finishers of 10000m race walk discipline, 33rd National Junior Athletic Championships, 2017 held at Acharya Nagarjuna University, Vijaywada, A. P. India were recorded by using two Nikon digital 4K camcorders (60 Hz) mounted on rigid tripods were placed alongside of the course at approximately 90° to the plane of motion. The junior athletes were analyzed by using motion analysis software (KINOVEA 0.8.27). Descriptive statistics and Pearson Product Moment Correlation coefficient (p<0.05) were employed for statistical calculation. The tabulation of data was done by using the IBM SPSS 25 software. The result of the study revealed that, women athlete’s performance were affected by the long contact phase duration (Mean=0.33 s (±) 0.05). This factor relativity creates hindrances in propulsive phase. A negative association (r= -0.49) found between contact time and average speed. As expected, due to the technical rules of this discipline knee angel at heel contact is significantly correlated with velocity as the calculated r value was 0.709* (Critical value at 8 df r = 0.632). Whereas, at mid stance phase a negative correlation found between knee angle and walking performance that sketch a hyper extended knee. However, a positive linear relationship found in variables like, hip angle, elbow angle at heel contact and mid stance phase with walking velocity. But, a less economical technique observed in toe off phase for almost every variable as those were negatively associated with mean speed, and so a balance between those fundamental techniques of support phase variables is advisable. The race walkers had shorter swing times, longer contact times, and smaller maximum knee flexion angles (152° ± 7.32) than the distance runners. The smaller knee flexion angles in race walkers meant they experienced greater swing leg moment of inertia than the distance runners.","PeriodicalId":261831,"journal":{"name":"American Journal of Sports Science and Medicine","volume":"71 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124858656","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Differences of Kinematic Parameters Javelin throw between Male and Female Finalists World Championship (Berlin, 2009-Daegu, 2011)","authors":"R. Pavlović, K. Idrizovic, Vladan Savić, Mensur Vrcić, Nikola Radulović, A. Simeonov","doi":"10.12691/AJSSM-8-1-2","DOIUrl":"https://doi.org/10.12691/AJSSM-8-1-2","url":null,"abstract":"Background: Kinematic parameters are an indispensable segment in the analysis of all throwing disciplines, including javelin throw. They are also an indicator of possible differences between competitors of different or the same rank of the competition and are an important factor for achieving a good result. The aim of the study was to determine the spatial and temporal differences of kinematic parameters in the javelin throw between the male and female finalists of the World Championships. Methods: The study was conducted on a sample of finalists in the World Athletics Championships (Berlin 2009-Daegu 2011) with the aim of determining the differences between the kinematic parameters of the male and between the female javelin throwers. The sample included a total of 32 competitors in both categories. To obtain the necessary results, a t-test for independent samples was applied. Result: statistically significant differences were confirmed between male finalists in 60% of kinematic parameters: release velocity (t=3,504; pConclusion: Generally speaking, this research showed that significant differences were observed between male finalists and between female finalists. Mostly, these are kinematic parameters that have proven to be paramount in the resultant performance of these championship throwers. One should not forget the influence of exogenous factors, above all air currents and javelin behavior as an aerodynamic device. An ideal biomechanical model of the thrower can be made based on the differences in the kinematic parameters of the top medal winners at the Berlin WCh in 2009 and the Daegu WCh in 2011.","PeriodicalId":261831,"journal":{"name":"American Journal of Sports Science and Medicine","volume":"53 ","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"113992719","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}