Pub Date : 2024-04-12DOI: 10.1177/17543371241246439
Deniz Şentürk, Oğuzhan Yüksel, Zeki Akyildiz
The present study had two main objectives: (i) to assess the concurrent validity and agreement of real-time measurement of counter-movement jump (CMJ) height using the My Jump Lab (MJL) mobile application in comparison to a force plate and (ii) to evaluate the intra-session reliability and agreement of the force plate and the MJL application. This cross-sectional investigation involved 36 recreationally active, healthy men (mean age = 22.2 ± 2.9 years) who performed five CMJ repetitions on the force plate with a 2-min rest period. Their jump heights were concurrently recorded using both the force plate and the MJL application. The high validity between the two methods intraclass correlation coefficient >0.984) was observed for all cases. There was a nearly perfect correlation ( r = 0.968, p = 0.001, in all cases) between the force plate and MJL application, with very good agreement and a mean difference of 1.016 cm (95% confidence interval: −1.229 to −0.803 cm). High intra-session reliability was observed in the force platform (SEM, 0.42 cm; CV, 1.21%; MDC, 1.5; SWC, 1.12), and MJL (SEM, 0.43 cm; CV, 1.23%; MDC, 1.20; SWC, 1.17). The results demonstrate that the MJL application is a valid and reliable tool for measuring jump performance in real-time and assessing CMJ height.
{"title":"The concurrent validity and reliability of the My Jump Lab smartphone app for the real-time measurement of vertical jump performance","authors":"Deniz Şentürk, Oğuzhan Yüksel, Zeki Akyildiz","doi":"10.1177/17543371241246439","DOIUrl":"https://doi.org/10.1177/17543371241246439","url":null,"abstract":"The present study had two main objectives: (i) to assess the concurrent validity and agreement of real-time measurement of counter-movement jump (CMJ) height using the My Jump Lab (MJL) mobile application in comparison to a force plate and (ii) to evaluate the intra-session reliability and agreement of the force plate and the MJL application. This cross-sectional investigation involved 36 recreationally active, healthy men (mean age = 22.2 ± 2.9 years) who performed five CMJ repetitions on the force plate with a 2-min rest period. Their jump heights were concurrently recorded using both the force plate and the MJL application. The high validity between the two methods intraclass correlation coefficient >0.984) was observed for all cases. There was a nearly perfect correlation ( r = 0.968, p = 0.001, in all cases) between the force plate and MJL application, with very good agreement and a mean difference of 1.016 cm (95% confidence interval: −1.229 to −0.803 cm). High intra-session reliability was observed in the force platform (SEM, 0.42 cm; CV, 1.21%; MDC, 1.5; SWC, 1.12), and MJL (SEM, 0.43 cm; CV, 1.23%; MDC, 1.20; SWC, 1.17). The results demonstrate that the MJL application is a valid and reliable tool for measuring jump performance in real-time and assessing CMJ height.","PeriodicalId":20674,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology","volume":"42 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140577925","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-09DOI: 10.1177/17543371241239725
Cengiz Akarçeşme, Elif Cengizel, Sümer Alvurdu, Emre Bağcı, Emre Altundağ, Çağdaş Özgür Cengizel, Ömer Şenel
The aim of this study is to determine the reliability and validity of the IVMES H-Bord eccentric hamstring strength measurement device. Thirty-eight healthy male athletes (age: 20.9 ± 2.11 years, height: 1.79 ± 0.03 m, body weight: 76.6 kg, body mass index: 22.6 ± 0.69 kg/m2) participated in this study. Each test protocol was applied in eccentric mode and isometric mode respectively. Between-session test-retest reliability of the IVMES H-Bord was analyzed for the intraclass correlation coefficient (ICC) with 95% coefficient intervals (CI). Validity of the IVMES H-Bord was examined for eccentric mode (NHTecc), and isometric mode (NHTiso) using Pearson’s correlation coefficient with 95% CI and limits of agreement. Bland-Altman plots were also created to provide a representation of the agreement between two test devices. Strong correlations, good ICC values and acceptable typical errors of the estimate were observed between the NHT and isokinetic strength testing (IST) during both limbs with no proportional bias for validity analysis. In conclusion, the “IVMES H-Bord” is a reliable and valid measurement device for eccentric hamstring muscle strength and it provides important advantages for medical staff, fitness coaches and practitioners because it is portable, low cost, and field-based assessment.
{"title":"Reliability and validity of the new portable Nordic hamstring test device (IVMES H-Bord)","authors":"Cengiz Akarçeşme, Elif Cengizel, Sümer Alvurdu, Emre Bağcı, Emre Altundağ, Çağdaş Özgür Cengizel, Ömer Şenel","doi":"10.1177/17543371241239725","DOIUrl":"https://doi.org/10.1177/17543371241239725","url":null,"abstract":"The aim of this study is to determine the reliability and validity of the IVMES H-Bord eccentric hamstring strength measurement device. Thirty-eight healthy male athletes (age: 20.9 ± 2.11 years, height: 1.79 ± 0.03 m, body weight: 76.6 kg, body mass index: 22.6 ± 0.69 kg/m<jats:sup>2</jats:sup>) participated in this study. Each test protocol was applied in eccentric mode and isometric mode respectively. Between-session test-retest reliability of the IVMES H-Bord was analyzed for the intraclass correlation coefficient (ICC) with 95% coefficient intervals (CI). Validity of the IVMES H-Bord was examined for eccentric mode (NHT<jats:sub>ecc</jats:sub>), and isometric mode (NHT<jats:sub>iso</jats:sub>) using Pearson’s correlation coefficient with 95% CI and limits of agreement. Bland-Altman plots were also created to provide a representation of the agreement between two test devices. Strong correlations, good ICC values and acceptable typical errors of the estimate were observed between the NHT and isokinetic strength testing (IST) during both limbs with no proportional bias for validity analysis. In conclusion, the “IVMES H-Bord” is a reliable and valid measurement device for eccentric hamstring muscle strength and it provides important advantages for medical staff, fitness coaches and practitioners because it is portable, low cost, and field-based assessment.","PeriodicalId":20674,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology","volume":"263 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140578148","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-09DOI: 10.1177/17543371241242914
Mike Rogerson, Daniel Knight, Reinhold Scherer, Ben Jones, Chris McManus, Sally Waterworth, Kelly Murray, Ed Hope
Video assistant referee (VAR) has been introduced to elite football (soccer) to avoid clear and obvious mistakes, especially for goal scoring situations. Some literature has reported on VAR’s impact on the game across particular league competitions. The current study meta-analysed data across two seasons (pre-VAR and post-VAR) from 20 competitions ( n = 9076 matches; men’s domestic leagues and both men’s and women’s international tournaments) to examine the overall impact that VAR initially had on number of goals scored, and the extent of inter-competition heterogeneity. A secondary aim was to determine any VAR-associated reduction in home advantage for goals scored, mean result direction and match closeness. Findings demonstrated that there were no overall statistically significant nor meaningful differences between pre and post-VAR seasons/competitions for total number of goals scored per match. Similarly, there were no VAR-associated reductions in home advantage in terms of goals scored, mean result direction and closeness of match outcome. There was moderate heterogeneity for some comparisons, and VAR lessened inter-competition variance for number of goals scored and match score closeness. Implications of findings are discussed. As the largest VAR-focused study and the first to use meta-analytic approach, the current findings are the most comprehensive and definitive to date.
视频助理裁判（VAR）已被引入精英足球比赛（足球），以避免明显和明显的错误，尤其是在进球的情况下。一些文献报道了 VAR 对特定联赛比赛的影响。本研究对来自 20 项赛事（n = 9076 场比赛；男子国内联赛以及男子和女子国际赛事）的两个赛季（VAR 前和 VAR 后）的数据进行了元分析，以研究 VAR 最初对进球数的总体影响，以及比赛间异质性的程度。另一个目的是确定 VAR 是否会减少主场优势的进球数、平均结果方向和比赛接近程度。研究结果表明，在每场比赛的总进球数方面，VAR 前和 VAR 后的赛季/比赛在总体统计上没有显著差异，也没有意义。同样，就进球数、平均结果走向和比赛结果的接近程度而言，主场优势也没有因 VAR 而减少。在一些比较中存在中等程度的异质性，而在进球数和比赛比分接近度方面，VAR 减少了比赛间的差异。本文讨论了研究结果的意义。作为规模最大的以 VAR 为重点的研究以及首个使用元分析方法的研究，目前的研究结果是迄今为止最全面、最权威的。
{"title":"Meta-analysis of the effects of VAR on goals scored and home advantage in football","authors":"Mike Rogerson, Daniel Knight, Reinhold Scherer, Ben Jones, Chris McManus, Sally Waterworth, Kelly Murray, Ed Hope","doi":"10.1177/17543371241242914","DOIUrl":"https://doi.org/10.1177/17543371241242914","url":null,"abstract":"Video assistant referee (VAR) has been introduced to elite football (soccer) to avoid clear and obvious mistakes, especially for goal scoring situations. Some literature has reported on VAR’s impact on the game across particular league competitions. The current study meta-analysed data across two seasons (pre-VAR and post-VAR) from 20 competitions ( n = 9076 matches; men’s domestic leagues and both men’s and women’s international tournaments) to examine the overall impact that VAR initially had on number of goals scored, and the extent of inter-competition heterogeneity. A secondary aim was to determine any VAR-associated reduction in home advantage for goals scored, mean result direction and match closeness. Findings demonstrated that there were no overall statistically significant nor meaningful differences between pre and post-VAR seasons/competitions for total number of goals scored per match. Similarly, there were no VAR-associated reductions in home advantage in terms of goals scored, mean result direction and closeness of match outcome. There was moderate heterogeneity for some comparisons, and VAR lessened inter-competition variance for number of goals scored and match score closeness. Implications of findings are discussed. As the largest VAR-focused study and the first to use meta-analytic approach, the current findings are the most comprehensive and definitive to date.","PeriodicalId":20674,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology","volume":"4 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140577919","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-06DOI: 10.1177/17543371241241846
Joseph Seydel
The effect of seam orientation relative to the spin axis on the forces of a rotating baseball has been studied, and debated, for as long as baseball has existed. Early debates centered on whether a spinning baseball could even curve and eventually changed to whether the orientation of seams had any impact on the forces acting on the ball during flight. This study uses Computational Fluid Dynamics to show that the seam orientation can have a significant influence on the lift force experienced by a baseball in flight, but that influence diminishes as the rate of spin approaches the natural shedding frequency of a sphere of the same size. Oscillations in the wake caused by the passing of seams across the upper and lower surface eventually give way to larger scale instabilities and the impact of seam orientation on the forces acting on the ball is significantly reduced.
{"title":"The influence of seam orientation on the lift and drag of a rotating baseball in flight","authors":"Joseph Seydel","doi":"10.1177/17543371241241846","DOIUrl":"https://doi.org/10.1177/17543371241241846","url":null,"abstract":"The effect of seam orientation relative to the spin axis on the forces of a rotating baseball has been studied, and debated, for as long as baseball has existed. Early debates centered on whether a spinning baseball could even curve and eventually changed to whether the orientation of seams had any impact on the forces acting on the ball during flight. This study uses Computational Fluid Dynamics to show that the seam orientation can have a significant influence on the lift force experienced by a baseball in flight, but that influence diminishes as the rate of spin approaches the natural shedding frequency of a sphere of the same size. Oscillations in the wake caused by the passing of seams across the upper and lower surface eventually give way to larger scale instabilities and the impact of seam orientation on the forces acting on the ball is significantly reduced.","PeriodicalId":20674,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology","volume":"13 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140577892","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-06DOI: 10.1177/17543371241241847
Iñigo Orue-Saiz, Markel Rico-González, José Pino-Ortega, Amaia Méndez-Zorrilla
Sports data analysis can revolutionize how coaches and athletes train, leading to enhanced skills and improved team outcomes by providing valuable insights into performance metrics, enabling personalized training programs, and fostering a data-driven approach to decision-making. Sports data analysis has evolved in tandem with the increasing availability of data and the widespread adoption of data-driven practices in sports. Futsal stands out as one of the most challenging team sports to analyze, particularly in the case of female futsal, which has received limited research attention. The high-paced nature of the game, the smaller playing area, and the emphasis on close ball control necessitate a specialized approach to data collection and analysis. This situation presents a significant opportunity for in-depth exploration. By recognizing a gap in utilizing nutrition and physical activity data for female futsal players, researchers embarked on the journey to design and develop a recommendation system based on diet and training data. The study enlisted 14 talented female futsal players, and data was collected using an advanced LPS (Local Positioning System) device. Despite having limited player information, researchers successfully addressed the well-known “cold start” challenge. They created a content-based filtering recommendation system that accurately predicts the caloric expenditure of futsal players, achieving an impressive determination coefficient of 0.94. This innovative system has the potential to revolutionize the training methods of female futsal players, paving the way for advancements in sports data analysis and opportunities to enhance the visibility of women’s futsal on a broader stage.
{"title":"Improving diet through a recommendation system using physical activity data and healthy diet indexes of female futsal players","authors":"Iñigo Orue-Saiz, Markel Rico-González, José Pino-Ortega, Amaia Méndez-Zorrilla","doi":"10.1177/17543371241241847","DOIUrl":"https://doi.org/10.1177/17543371241241847","url":null,"abstract":"Sports data analysis can revolutionize how coaches and athletes train, leading to enhanced skills and improved team outcomes by providing valuable insights into performance metrics, enabling personalized training programs, and fostering a data-driven approach to decision-making. Sports data analysis has evolved in tandem with the increasing availability of data and the widespread adoption of data-driven practices in sports. Futsal stands out as one of the most challenging team sports to analyze, particularly in the case of female futsal, which has received limited research attention. The high-paced nature of the game, the smaller playing area, and the emphasis on close ball control necessitate a specialized approach to data collection and analysis. This situation presents a significant opportunity for in-depth exploration. By recognizing a gap in utilizing nutrition and physical activity data for female futsal players, researchers embarked on the journey to design and develop a recommendation system based on diet and training data. The study enlisted 14 talented female futsal players, and data was collected using an advanced LPS (Local Positioning System) device. Despite having limited player information, researchers successfully addressed the well-known “cold start” challenge. They created a content-based filtering recommendation system that accurately predicts the caloric expenditure of futsal players, achieving an impressive determination coefficient of 0.94. This innovative system has the potential to revolutionize the training methods of female futsal players, paving the way for advancements in sports data analysis and opportunities to enhance the visibility of women’s futsal on a broader stage.","PeriodicalId":20674,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology","volume":"41 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140577697","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-28DOI: 10.1177/17543371241237588
Evan Christopher Mascitti, Andrew Scott McNitt
Baseball and softball are played primarily on the infield skin. An ideal infield surface allows players’ cleats to penetrate the soil and provide adequate traction yet impart minimal surface disruption. This ideal state has been termed the “cleat-in/cleat-out effect.” As an infield soil dries, it transitions from the cleat-in/cleat-out state to a brittle condition in which the soil readily fractures into chips or clods. . Surface irregularities formed in the brittle condition may deflect batted balls and induce a fielding error or injury. The objective of this research was to develop a laboratory test for identifying the critical water content [Formula: see text] corresponding to the cleat-in/cleat-out behavioral threshold for any soil. A pneumatically driven apparatus was fabricated to emulate an athlete’s footstrike by applying normal, shearing, and torsional stresses using baseball cleats removed from a commercially available shoe. The test produced several cleat indentations on a cylindrical soil sample. A 3D scanning technique quantified surface disruption via Dirichlet Normal Energy. Volumetric water content was measured using a combination of 3D scanning and gravimetric methods. A given soil sample was tested at several water contents. [Formula: see text] was determined by plotting Dirichlet Normal Energy against θ and fitting a curve to solve for the local minimum. The method successfully detected differences in [Formula: see text] between infield soils containing identical clay mineralogy but differing sand content (60% and 75%; p < 0.001). Reasonable correspondence was achieved across test replicates, with a coefficient of variation of 8.5%. It is envisaged that the method will find utility in future investigations of infield mix design.
棒球和垒球主要在内野表层进行。理想的内场表面可以让球员的球鞋穿透土壤，提供足够的牵引力，同时将表面破坏降到最低。这种理想状态被称为 "球鞋穿进/穿出效应"。随着内场土壤的干燥，它会从 "鞋垫进/鞋垫出 "状态转变为脆性状态，在这种状态下，土壤很容易断裂成碎屑或泥块。在脆性状态下形成的表面不规则可能会使击球发生偏转，从而导致击球失误或受伤。本研究的目的是开发一种实验室测试方法，用于确定与任何土壤的裂入/裂出行为阈值相对应的临界含水量[公式：见正文]。我们制作了一个气动装置，通过使用从市售鞋中拆下的棒球鞋垫施加法向、剪切和扭转应力来模拟运动员的脚部击球。测试在圆柱形土壤样本上产生了多个鞋垫压痕。三维扫描技术通过 Dirichlet 法向能量对表面破坏进行量化。体积含水量的测量结合使用了三维扫描和重量测量方法。在多个含水量条件下对特定土壤样本进行测试。[公式：见正文]是通过绘制 Dirichlet Normal Energy 与 θ 的关系图并拟合曲线以求解局部最小值来确定的。该方法成功地检测出了含有相同粘土矿物性但含沙量不同（60% 和 75%；p <；0.001）的田间土壤之间[公式：见正文]的差异。各测试重复之间实现了合理的对应，变异系数为 8.5%。预计该方法将在未来的内场混合设计研究中发挥作用。
{"title":"A laboratory method to measure deformation of baseball infield soil surfaces using cleated footwear","authors":"Evan Christopher Mascitti, Andrew Scott McNitt","doi":"10.1177/17543371241237588","DOIUrl":"https://doi.org/10.1177/17543371241237588","url":null,"abstract":"Baseball and softball are played primarily on the infield skin. An ideal infield surface allows players’ cleats to penetrate the soil and provide adequate traction yet impart minimal surface disruption. This ideal state has been termed the “cleat-in/cleat-out effect.” As an infield soil dries, it transitions from the cleat-in/cleat-out state to a brittle condition in which the soil readily fractures into chips or clods. . Surface irregularities formed in the brittle condition may deflect batted balls and induce a fielding error or injury. The objective of this research was to develop a laboratory test for identifying the critical water content [Formula: see text] corresponding to the cleat-in/cleat-out behavioral threshold for any soil. A pneumatically driven apparatus was fabricated to emulate an athlete’s footstrike by applying normal, shearing, and torsional stresses using baseball cleats removed from a commercially available shoe. The test produced several cleat indentations on a cylindrical soil sample. A 3D scanning technique quantified surface disruption via Dirichlet Normal Energy. Volumetric water content was measured using a combination of 3D scanning and gravimetric methods. A given soil sample was tested at several water contents. [Formula: see text] was determined by plotting Dirichlet Normal Energy against θ and fitting a curve to solve for the local minimum. The method successfully detected differences in [Formula: see text] between infield soils containing identical clay mineralogy but differing sand content (60% and 75%; p < 0.001). Reasonable correspondence was achieved across test replicates, with a coefficient of variation of 8.5%. It is envisaged that the method will find utility in future investigations of infield mix design.","PeriodicalId":20674,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology","volume":"9 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140324284","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-26DOI: 10.1177/17543371241237589
Asım Tunçel, Nihat Özgören, Serdar Aritan
This study aimed to understand the collision characteristics of different soccer balls by determining energy dissipation (ED) during collisions. Soccer balls from five different brands were kicked towards a framed tempered glass. The kicks were performed with the balls inflated under three inner pressure conditions. The motion of each ball was recorded using two high-speed cameras at 6000 Hz. The contact surface area (CSA), ball indentation amount (IA), reaction forces (RF) and energetic coefficient of restitution (CoR) during contact were calculated via image processing methods. A new methodological approach was developed to determine the ED during the collision (EDDC). The accuracy of the estimated RF was validated using force plate data, and the CSA values validated the calculated IA. The EDDC were then reduced to a single value to compare with the CoR values obtained using the traditional formula. Differences between CoR and EDDC were statistically tested. One-way ANOVA tests were performed separately to compare the effect of the ball brand on the IA and EDDC for each inner pressure condition. The CoR and EDDC showed no significant difference, proving that the developed method is a valid measure of ED. At 1.0 bar inner pressure, IA and EDDC showed significant differences according to the brands. EDDC, depending on the ball quality, decreased at higher inner pressure values regardless of the brand. Consequently, the present study exhibited that ball quality becomes a critical factor in collision dynamics at high inner pressure values, considering that ball inner pressure may vary between 0.6 and 1.0 bar in official soccer matches.
{"title":"Comparison of collision dynamics of soccer balls with energy dissipation method","authors":"Asım Tunçel, Nihat Özgören, Serdar Aritan","doi":"10.1177/17543371241237589","DOIUrl":"https://doi.org/10.1177/17543371241237589","url":null,"abstract":"This study aimed to understand the collision characteristics of different soccer balls by determining energy dissipation (ED) during collisions. Soccer balls from five different brands were kicked towards a framed tempered glass. The kicks were performed with the balls inflated under three inner pressure conditions. The motion of each ball was recorded using two high-speed cameras at 6000 Hz. The contact surface area (CSA), ball indentation amount (IA), reaction forces (RF) and energetic coefficient of restitution (CoR) during contact were calculated via image processing methods. A new methodological approach was developed to determine the ED during the collision (EDDC). The accuracy of the estimated RF was validated using force plate data, and the CSA values validated the calculated IA. The EDDC were then reduced to a single value to compare with the CoR values obtained using the traditional formula. Differences between CoR and EDDC were statistically tested. One-way ANOVA tests were performed separately to compare the effect of the ball brand on the IA and EDDC for each inner pressure condition. The CoR and EDDC showed no significant difference, proving that the developed method is a valid measure of ED. At 1.0 bar inner pressure, IA and EDDC showed significant differences according to the brands. EDDC, depending on the ball quality, decreased at higher inner pressure values regardless of the brand. Consequently, the present study exhibited that ball quality becomes a critical factor in collision dynamics at high inner pressure values, considering that ball inner pressure may vary between 0.6 and 1.0 bar in official soccer matches.","PeriodicalId":20674,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology","volume":"128 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140311412","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-22DOI: 10.1177/17543371241240627
Konstantin I Matveev
Hydrodynamic performance of windsurfing boards is greatly affected by geometrical details of their bottom surfaces. In this study, computational fluid dynamics is applied to simulate flow around boards with several bottom modifications, including deadrise, rocker, step, wedge, and wing-tail profile. These simulations are conducted in steady-state, calm-water regimes at high planing speeds. It is found that at similar board trim angles and vertical positions, the largest lift is produced by setups with the bottom wedge and the wing-tail profile that enhance the downward deflection of the incident water flow. The highest lift-drag ratio is achieved by the variants with the bottom step and wedge that enable partial air ventilation of the bottom surface, which leads to reduced wetted surface and lower frictional resistance. The center of lift is located more forward on the rocker and stepped configurations, while it is positioned more rearward for the wedge and wing-tail setups. The obtained results can be used for guiding board designs aimed at maximizing the board hydrodynamic performance in calm water.
{"title":"Hydrodynamic performance of windsurfing boards with bottom modifications at high speed in calm water","authors":"Konstantin I Matveev","doi":"10.1177/17543371241240627","DOIUrl":"https://doi.org/10.1177/17543371241240627","url":null,"abstract":"Hydrodynamic performance of windsurfing boards is greatly affected by geometrical details of their bottom surfaces. In this study, computational fluid dynamics is applied to simulate flow around boards with several bottom modifications, including deadrise, rocker, step, wedge, and wing-tail profile. These simulations are conducted in steady-state, calm-water regimes at high planing speeds. It is found that at similar board trim angles and vertical positions, the largest lift is produced by setups with the bottom wedge and the wing-tail profile that enhance the downward deflection of the incident water flow. The highest lift-drag ratio is achieved by the variants with the bottom step and wedge that enable partial air ventilation of the bottom surface, which leads to reduced wetted surface and lower frictional resistance. The center of lift is located more forward on the rocker and stepped configurations, while it is positioned more rearward for the wedge and wing-tail setups. The obtained results can be used for guiding board designs aimed at maximizing the board hydrodynamic performance in calm water.","PeriodicalId":20674,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology","volume":"26 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140203165","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-21DOI: 10.1177/17543371241237319
Tomasz Szot
Global Navigation Satellite Systems (GNSSs) have revolutionised many areas of human life by providing location, navigation, tracking, mapping and timing capabilities. The use of this technology would not be possible without receivers designed for specific applications. One of these areas is sport. The article discusses the advancements made in wearable sport devices over the past two decades (2003–2023) and uses Garmin’s Forerunner receivers as an example. Nineteen of the most advanced models were analysed chronologically and reviewed in three sections: physical properties, internal and external sensors and other functional aspects. The lists are preceded by a description of the historical background of the technology, an explanation of the general principles of operation and the identification of ground-breaking mobile devices before the year 2003. The summary identifies the most likely changes that will affect the publicly available, wearable sports GNSS receivers in the near future.
{"title":"Evolution of sport wearable global navigation satellite systems’ receivers: A look at the Garmin Forerunner series","authors":"Tomasz Szot","doi":"10.1177/17543371241237319","DOIUrl":"https://doi.org/10.1177/17543371241237319","url":null,"abstract":"Global Navigation Satellite Systems (GNSSs) have revolutionised many areas of human life by providing location, navigation, tracking, mapping and timing capabilities. The use of this technology would not be possible without receivers designed for specific applications. One of these areas is sport. The article discusses the advancements made in wearable sport devices over the past two decades (2003–2023) and uses Garmin’s Forerunner receivers as an example. Nineteen of the most advanced models were analysed chronologically and reviewed in three sections: physical properties, internal and external sensors and other functional aspects. The lists are preceded by a description of the historical background of the technology, an explanation of the general principles of operation and the identification of ground-breaking mobile devices before the year 2003. The summary identifies the most likely changes that will affect the publicly available, wearable sports GNSS receivers in the near future.","PeriodicalId":20674,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology","volume":"363 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140203072","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-14DOI: 10.1177/17543371241237085
Brindha Jayakumar, Nallavan Govindarajan
Recent advancements in deep learning have significantly enhanced the recognition of player activities in sports by enabling automatic feature extraction. In our proposed work, we focus on recognizing six distinct punches in the context of boxing. We incorporate the sliding window technique during the pre-processing stage to transform the time-series data obtained from Inertial Measurement Unit (IMU) sensors in a boxing punch activity recognition system. Our approach influences a sensor fusion-based Deep Convolutional Neural Network (DCNN) classification model to identify various boxing punches accurately, achieving an impressive F1 score. The system demonstrates proficiency in distinguishing similar activities, such as jab and hook punches where the existing systems made misclassifications due to subtle variations in arm flexion that differentiate the two. Through experimentation, we identify an optimal window size for boxing punch activity recognition, which falls within the range of 15–20 frames (equivalent to 0.15–0.25 s). This window size selection results in a notable reduction in inference time. To evaluate our proposed model, we conduct comparisons with a standard DCNN and an optimized DCNN model. Our proposed optimized DCNN model demonstrates enhanced recognition accuracy, achieving an impressive 99%, coupled with an improved F1 score of 87%. Furthermore, the model displays a remarkable reduction in inference time, clocking in at less than 1 ms. Overall, our research contributes to the field of sports-related player activity recognition by employing the power of deep learning. By expertly combining these techniques, we achieve remarkable accuracy, precision, and efficiency in recognizing various boxing punches.
{"title":"Multi-sensor fusion based optimized deep convolutional neural network for boxing punch activity recognition","authors":"Brindha Jayakumar, Nallavan Govindarajan","doi":"10.1177/17543371241237085","DOIUrl":"https://doi.org/10.1177/17543371241237085","url":null,"abstract":"Recent advancements in deep learning have significantly enhanced the recognition of player activities in sports by enabling automatic feature extraction. In our proposed work, we focus on recognizing six distinct punches in the context of boxing. We incorporate the sliding window technique during the pre-processing stage to transform the time-series data obtained from Inertial Measurement Unit (IMU) sensors in a boxing punch activity recognition system. Our approach influences a sensor fusion-based Deep Convolutional Neural Network (DCNN) classification model to identify various boxing punches accurately, achieving an impressive F1 score. The system demonstrates proficiency in distinguishing similar activities, such as jab and hook punches where the existing systems made misclassifications due to subtle variations in arm flexion that differentiate the two. Through experimentation, we identify an optimal window size for boxing punch activity recognition, which falls within the range of 15–20 frames (equivalent to 0.15–0.25 s). This window size selection results in a notable reduction in inference time. To evaluate our proposed model, we conduct comparisons with a standard DCNN and an optimized DCNN model. Our proposed optimized DCNN model demonstrates enhanced recognition accuracy, achieving an impressive 99%, coupled with an improved F1 score of 87%. Furthermore, the model displays a remarkable reduction in inference time, clocking in at less than 1 ms. Overall, our research contributes to the field of sports-related player activity recognition by employing the power of deep learning. By expertly combining these techniques, we achieve remarkable accuracy, precision, and efficiency in recognizing various boxing punches.","PeriodicalId":20674,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology","volume":"27 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140152243","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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