N.S. Vracas, D. Short, J. Banks, D. Taunton, S. Turnock
{"title":"A trajectory simulation model to analyse the factors influencing the descent of a Skeleton athlete","authors":"N.S. Vracas, D. Short, J. Banks, D. Taunton, S. Turnock","doi":"10.1177/17543371221150820","DOIUrl":"https://doi.org/10.1177/17543371221150820","url":null,"abstract":"Subtle differences in aerodynamic drag, ice friction and sprint start, all influenced by the skill and physique of athletes, determine the descent time and hence competitive success in the sport of Skeleton. A trajectory based simulation was created by parameterising the geometry of the Altenberg Ice Track in Saxony, Germany to find the physically realistic descent time that captures the physics of the aerodynamic drag, ice friction and sprint start. A sensitivity study was used to analyse the influence of each factor on the overall performance down a fixed mid-line trajectory. Comparisons are made to the actual descent times to confirm applicability for a set of male and female sliders. It was found that the combined mass of the athlete and sled should be maximised within the rules, the initial velocity from the push should be as fast as possible, the aerodynamic drag should be optimised for each athlete and the ice friction of the runners reduced to their lowest limit. If each variable is optimum, then the final race standings will depend solely on the skill of the athlete traversing the ice track by finding the ‘best’ trajectory.","PeriodicalId":20674,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology","volume":" ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2023-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46954755","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}
William D Ferriell, N. Wright, J. DesJardins, Gregory S. Batt
{"title":"Parametric design methods development for the comparison of American football faceguards using validated structural stiffness models","authors":"William D Ferriell, N. Wright, J. DesJardins, Gregory S. Batt","doi":"10.1177/17543371221140674","DOIUrl":"https://doi.org/10.1177/17543371221140674","url":null,"abstract":"Recent advances in headgear design research have sought to inform athletes’ safety related decisions by ranking headgear systems according to impact performance. These rankings have provided athletes with greater agency in their safety-related decisions. Despite these improvements, little quantitative information exists to compare faceguard performance. Using validated structural stiffness finite element models, this study sought to develop a parametric design approach that could be consistently applied to faceguards of different qualitative categories and of different helmet-compatible series. The methods presented in this study detail the objective measurement techniques and parameters of interest used to fully define three common American football faceguards. The results of this study indicate an ability to define parameters consistently for faceguards of different qualitative categories and of different helmet-compatible series. The high degree of correlation between mass and structural stiffness indicates expected model performance – providing increased confidence in results. Intuitively, the greatest effect on mass and structural stiffness was the size of the diameter of the main bars. Increases in mass were achieved with minimal changes in structural stiffness. Conversely, increases in structural stiffness were achieved with minimal changes in mass. These results have implications for manufacturers as some faceguards, such as those classified as “overbuilt,” are banned – in part – for their weight. Future work should continue to compare manufacturers’ original designs and investigate other metrics to further quantify performance and safety for athletes. This tool may be used to improve new faceguard designs by comparing new models to faceguards allowed for use.","PeriodicalId":20674,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology","volume":" ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2023-01-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42110907","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}
Kalle Kalliorinne, Gustav Hindér, J. Sandberg, R. Larsson, H. Holmberg, A. Almqvist
{"title":"The impact of cross-country skiers’ tucking position on ski-camber profile, apparent contact area and load partitioning","authors":"Kalle Kalliorinne, Gustav Hindér, J. Sandberg, R. Larsson, H. Holmberg, A. Almqvist","doi":"10.1177/17543371221141748","DOIUrl":"https://doi.org/10.1177/17543371221141748","url":null,"abstract":"In cross-country skiing races, the difference between the fastest and the second fastest time can be minuscule. As in all endurance sports, cross-country skiing requires the use of energy to overcome resistive forces, in this case primarily aerodynamic drag and friction between the skis and snow. Even a slight reduction in either of these can determine the outcome of a race. The geometry of the ski exerts a profound influence on the friction between the skis and snow. As a result of the flexible modern cross-country skis, the camber profile and gliding properties to be influenced by the skiers’ position. Here, based on the location of the normal force corresponding to the plantar pressure, we characterize the ski camber while performing three variations of the downhill tucking position. We found that when gliding on a classic ski, the risk of contact between the kick wax and snow can be reduced by tucking in a leaning backwards position (i.e. by moving the skier’s center of mass backwards). With the tucking position, the percentage of the skier’s body weight that is distributed onto the friction interface at the rear of the skis varies between 63.5% in Gear 7 (leaning forward) on a skating ski and 93.0% in Gear 7 (leaning backwards) on a classic ski.","PeriodicalId":20674,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology","volume":" ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2023-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42913891","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}
A. Gruber, L. Marotta, James McDonnell, J. Reenalda
{"title":"All devices are not created equal: Simultaneous data collection of three triaxial accelerometers sampling at different frequencies","authors":"A. Gruber, L. Marotta, James McDonnell, J. Reenalda","doi":"10.1177/17543371221140517","DOIUrl":"https://doi.org/10.1177/17543371221140517","url":null,"abstract":"The surge of wearable device technology has enabled out-of-the-lab collection of running gait data for commercial, clinical, and coaching applications. However, low sampling frequencies interfere with measuring peak acceleration magnitudes accurately, and the ability to track relative changes during a prolonged run with lower sampling devices is unknown. The purposes of this study were to compare peak resultant acceleration measured simultaneously at different sampling frequencies and evaluate if different sampling frequencies could track similar relative changes in peak acceleration over a 20-min treadmill run. Seventeen participants ran on a treadmill at a self-selected, “easy” pace for 20-min (mean ± SD = 2.6 ± 0.4 m s−1). Three research-grade, triaxial accelerometers (“HiRes” = 1200 Hz, “MedRes” = 462 Hz, and “LoRes” = 100 Hz) were secured to each of three anatomical locations (tibia, low-back, forehead). Mean peak resultant accelerations from each device during minutes 3 to 18 were compared within each location (linear mixed model, α = 0.050). No significant device by timepoint interaction was observed ( p > 0.999). A significant main effect of sampling frequency at all three locations (HiRes > MedRes > LoRes; p < 0.001) confirmed the underestimation of low sampling frequencies on peak resultant acceleration. However, the significant main effect of time indicated that peak resultant acceleration changed similarly over time between sampling frequencies at the tibia ( p = 0.010) and head ( p = 0.002), but not the low-back ( p = 0.318). Downsampling HiRes to 400 and 100 Hz reduced the underestimation of the resultant peaks within the MedRes and LoRes signals by <7.7% across anatomical locations. This study confirms sampling frequency of wearable devices significantly affects peak resultant acceleration and demonstrates these effects are greater for signals captured at lower sampling frequencies and caudal locations. Despite these effects, this study cautiously supports the use of ≥100 Hz sampling frequencies for within-individual peak resultant acceleration tracking during “easy” prolonged runs for research, clinical, and coaching applications.","PeriodicalId":20674,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology","volume":" ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2022-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48957892","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}
Masashi Ohara, N. Kawasaki, Hyunwoo Song, Ayane Shinojima, Yuma Naka, Y. Takada, Hitoshi Watanabe
{"title":"Development of a shooting machine for the selection of arrows","authors":"Masashi Ohara, N. Kawasaki, Hyunwoo Song, Ayane Shinojima, Yuma Naka, Y. Takada, Hitoshi Watanabe","doi":"10.1177/17543371221141779","DOIUrl":"https://doi.org/10.1177/17543371221141779","url":null,"abstract":"It is important to select reliable tools that archers should use in archery competitions. For this reason, we focused on the arrows among the tools and developed a shooting machine for selecting arrows. It is important to imitate the movement of the right finger to release the arrow and the forward movement of the bow after the arrow is released. Therefore, these factors were considered when designing the machine. In this study, a shooting experiment was conducted in which the shooting cycle of twelve ends of six arrows was repeated five times (one end is defined as six arrows). Next, using the data from the impact points on the target, specific arrows with a large dispersion were identified. Cluster analysis was then conducted to identify the arrows that showed a high similarity distribution. Based on the above results, we were able to identify arrows with the most flaws and select arrows that archers should use. The results indicate the effectiveness of the method of selecting reliable arrows by rejecting flawed arrows.","PeriodicalId":20674,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology","volume":" ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2022-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43977715","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}
Guido Contreras-Díaz, L. Chirosa-Ríos, D. Martínez-García, L. Intelangelo, I. Chirosa-Ríos, D. Jérez-Mayorga
{"title":"Reliability of isokinetic hip abductor and adductor strength measurements: A systematic review and meta-analysis","authors":"Guido Contreras-Díaz, L. Chirosa-Ríos, D. Martínez-García, L. Intelangelo, I. Chirosa-Ríos, D. Jérez-Mayorga","doi":"10.1177/17543371221137965","DOIUrl":"https://doi.org/10.1177/17543371221137965","url":null,"abstract":"The aims of this study were to: (I) examine the reliability of the abduction and adduction isokinetic strength measurements in healthy subjects and athletes; (II) determine which position is the most valid and reliable for strength measurement; and (III) determine the most reliable velocity to assess hip abductor and adductor strength. The databases used were Web of Science, SCOPUS, MedLine and PubMed. The metafor package of R software was used to conduct meta-analysis. A total of 767 studies were identified through a search of electronic databases, of which 10 were included in this meta-analysis. The main finding of the study revealed; (I) the reliability of isokinetic force measurement is good in abduction (ICC = 0.83) and adduction (ICC = 0.81); (II) standing position presents good reliability in abduction (ICC = 0.83) and adduction (ICC = 0.79); (III) the lateral position presents good reliability in abduction (ICC = 0.83) and adduction (ICC = 0.82); (IV) the velocity of 60°/s (ICC = 0.84), 90°/s (ICC = 0.84) and 120°/s (ICC = 0.86) show good reliability for abduction, and; (V) the velocity of 30°/s (ICC = 0.76), 60°/s (ICC = 0.83), and 120°/s (ICC = 0.89) show good reliability for adduction. Many factors influence the reliability of isokinetic assessments of the hip abductors and adductors, the best known of which are body position, isokinetic velocity, and type of muscle contraction. And although most of the researchers opt for the evaluation in lateral position, and at low velocities, our results conclude that the standing position, at a velocity of 120°/s is a better alternative to evaluate these movements (ABD-ADD), and not only because of its good reliability, but also because of the similarity of the evaluation with the gestures developed within the sport.","PeriodicalId":20674,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology","volume":" ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2022-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41733562","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}
A. E. Tümer, Zeki Akyildiz, Aytek Hikmet Güler, Esat Kaan Saka, Riccardo Ievoli, Lucio Palazzo, F. Clemente
{"title":"Prediction of soccer clubs’ league rankings by machine learning methods: The case of Turkish Super League","authors":"A. E. Tümer, Zeki Akyildiz, Aytek Hikmet Güler, Esat Kaan Saka, Riccardo Ievoli, Lucio Palazzo, F. Clemente","doi":"10.1177/17543371221140492","DOIUrl":"https://doi.org/10.1177/17543371221140492","url":null,"abstract":"The aim of this research is to predict league rankings through various machine learning models using technical and physical parameters. This study followed a longitudinal observational analytical design. The SENTIO Sports optical tracking system was used to measure the physical demands and technical practices of the players in all matches. Then, the data regarding the last three seasons of the Turkish Super League (2015–2016, 2016−2017, and 2017−2018), was collected. In this research, league rankings were estimated using three machine learning methods: Artificial Neural Networks (ANN), Radial Basis Function (RBFN), Multiple Linear Regression (MLR) with technical and physical parameters of all seasons. Performances were evaluated through R2, Root Mean Square Error (RMSE), and Mean Absolute Error (MAE). Prediction results of the models are the following: ANN Model; R2 = 0.60, RMSE = 3.7855 and MAE = 2.9139, RBFN Model; R2 = 0.26, MAE = 3.6292 and RMSE = 4.5168, MLR Model; R2 = 0.46, MAE = 3.4859 and RMSE = 4.2064. These results showed that ANN can be used as a successful tool to predict league rankings. In the light of this research, coaches and athletic trainers can organize their training in a way that affects the technical and physical parameters to change the results of the competition. Thus, it will be possible for teams to have a better place in the league-end success ranking.","PeriodicalId":20674,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology","volume":" ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2022-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43805034","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}
Rui Pacheco, João Ribeiro, M. Couceiro, K. Davids, J. Garganta, I. Marques-Aleixo, Fábio Nakamura, Filipe Casanova, S. González-Víllora
{"title":"Development of an innovative method for evaluating a network of collective defensive interactions in football","authors":"Rui Pacheco, João Ribeiro, M. Couceiro, K. Davids, J. Garganta, I. Marques-Aleixo, Fábio Nakamura, Filipe Casanova, S. González-Víllora","doi":"10.1177/17543371221141584","DOIUrl":"https://doi.org/10.1177/17543371221141584","url":null,"abstract":"Social network analysis (SNA) has been increasingly applied to performance analytics in team sports, seeking to better understand the dynamic properties of competitive interactions. Despite considerable potential to analyze individual (micro) and team (macro) behavioral patterns of play, there are important limitations that can undermine the potential applicability of SNA. One important limitation in existing research is the lack of network analyses of defensive interactions, curtailing understanding of the functionality and adaptability of teams during competitive performance. This study developed an innovative network method for assessing interactions between players in defensive phases of play in football. The networking method was evaluated using a small-sided and conditioned game (SSCG; GK+7v7+GK) of 20 min duration (two halves of 10 min each, interspersed by 5 min intervals of active recovery). The method traced interactions between groups of three players (effective defensive triangulations) as network nodes, weighted according to the number of passes performed by the attacking players. Results showed how this social network analysis method may provide researchers, coaches and performance analysts with relevant information regarding the functional properties of teams in the defensive phase of the game. For instance, coaches and performance analysts can evaluate the geometry of a team’s defense, with players engaged in effective triangular-shaped positioning, that allowed them to provide defensive cover and balance, to protect the goal and recover ball possession.","PeriodicalId":20674,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology","volume":" ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2022-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41524904","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}
{"title":"A comparison of protocols for measuring forces during landing on competition mats in gymnastics","authors":"Emma L Buxton, M. Hiley, M. Yeadon","doi":"10.1177/17543371221140495","DOIUrl":"https://doi.org/10.1177/17543371221140495","url":null,"abstract":"During apparatus dismounts gymnasts land from up to 4 m above the landing surface. The gymnast needs to withstand high impact forces and the use of landing mats allows gymnasts to attenuate the forces with their landing strategy and interaction with the landing mats. Competition landings from various gymnastics apparatus involve the use of a 200 mm thick landing mat, with an additional 100 mm thick mat placed on top. The purpose of this research was to investigate the experimental protocols for measuring forces using force platforms during landings on competition mats. Three experimental protocols were compared, each of which used a force platform underneath landing mats in various set-ups. In Protocol 1 the mats were placed directly onto the force platform; in Protocol 2 the mats were placed on an enlarged raised extension; in Protocol 3 smaller mats were used with the extension. Differences between the vertical landing velocities calculated from kinematic data and from force platform data were used to assess how much impulse was transferred to the force platform in each of the protocols. Protocol 3 was the preferred method for collecting landing forces and resulted in a mean percentage velocity absolute difference of less than 2% for both one-mat and two-mat conditions. This study demonstrates the importance of keeping the landing mats clear of the force platform surroundings during the whole of the landing phase.","PeriodicalId":20674,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology","volume":" ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2022-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46981302","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}
{"title":"Aerodynamic comparisons between Al Rihla and recent World Cup soccer balls","authors":"J. Goff, Sungchan Hong, T. Asai","doi":"10.1177/17543371221140497","DOIUrl":"https://doi.org/10.1177/17543371221140497","url":null,"abstract":"Wind-tunnel experiments were performed on Al Rihla, Telstar 18, Brazuca, and Jabulani, official match soccer balls used in the World Cup in 2022, 2018, 2014, and 2010, respectively. Aerodynamic coefficients extracted from wind-tunnel results were used to create computer simulations of trajectories of kicked soccer balls. The newest World Cup ball, Al Rihla, could be kicked for longer range compared to its recent predecessors. But there is also the possibility that knuckling effects at large speeds could be seen in the flights of the new ball kicked with little to no spin. Measurements were made of each soccer ball’s total seam length and seam width and depth. Two different measurement techniques were employed to assist with accuracy. Wider and deeper seams led to smaller critical speeds.","PeriodicalId":20674,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology","volume":" ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2022-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48736026","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}