Pub Date : 2024-09-19DOI: 10.1177/17543371241279576
Vasilis Armatas
Transitions, rapid attacks after regaining possession, are a potent weapon, yet their lower frequency compared to organized attacks highlights a need for understanding factors that influence their success, particularly regarding offensive sector entry. This study investigates factors influencing the success of transitions, with a specific focus on predicting their ability to penetrate the opponent’s offensive sector. We analyzed 1911 ball recoveries from the 2018 to 2019 Greek SuperLeague. Chi-squared tests and binary logistic regression were employed to examine the influence of recovery type, number of defenders, passing patterns (including penetrative passes), and other variables on successful transitions. Our findings reveal that the likelihood of entering the offensive sector significantly increased when the ball was recovered in advanced areas, against fewer defenders, involved a high proportion of penetrative passes, and had a longer offensive sequence duration. This model provides a framework for predicting offensive sector entry during transitions, offering valuable insights for coaches seeking to optimize training drills and maximize transitional effectiveness.
{"title":"Predicting offensive sector entry during transition moments in soccer","authors":"Vasilis Armatas","doi":"10.1177/17543371241279576","DOIUrl":"https://doi.org/10.1177/17543371241279576","url":null,"abstract":"Transitions, rapid attacks after regaining possession, are a potent weapon, yet their lower frequency compared to organized attacks highlights a need for understanding factors that influence their success, particularly regarding offensive sector entry. This study investigates factors influencing the success of transitions, with a specific focus on predicting their ability to penetrate the opponent’s offensive sector. We analyzed 1911 ball recoveries from the 2018 to 2019 Greek SuperLeague. Chi-squared tests and binary logistic regression were employed to examine the influence of recovery type, number of defenders, passing patterns (including penetrative passes), and other variables on successful transitions. Our findings reveal that the likelihood of entering the offensive sector significantly increased when the ball was recovered in advanced areas, against fewer defenders, involved a high proportion of penetrative passes, and had a longer offensive sequence duration. This model provides a framework for predicting offensive sector entry during transitions, offering valuable insights for coaches seeking to optimize training drills and maximize transitional effectiveness.","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":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142266590","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}
This study aimed to classify the movements of female soccer players during matches using raw data measured by inertial measurement units (IMUs). Twelve collegiate female soccer players were equipped with IMUs (100 Hz), and raw triaxial acceleration data from eight official matches were analyzed. The measurement data were separated every 3 s, and a Fast Fourier Transform (FFT) was performed. After FFT, the Euclidean distances between the data when the players were in the stationary state and other states were calculated to classify the movements of the players using the k-means method. The data of the clustering numbers classified as the stationary state were eliminated after analyzing the movements of players by video filming the matches. After classification, the average Euclidean distances between the stationary state and other movements were calculated. Consequently, the results showed that the upward and downward directions of the raw data affected the classification. Using the methods of this study, it was also shown that the distribution of Euclidean distances differed from player to player. Our findings indicate that the method used in this study can be used to classify and characterize the movements of female collegiate soccer players.
{"title":"Classification of movements of collegiate female soccer players using inertial measurement units","authors":"Yuki Masui, Nobuyoshi Hirotsu, Yu Shimasaki, Masafumi Yoshimura","doi":"10.1177/17543371241278032","DOIUrl":"https://doi.org/10.1177/17543371241278032","url":null,"abstract":"This study aimed to classify the movements of female soccer players during matches using raw data measured by inertial measurement units (IMUs). Twelve collegiate female soccer players were equipped with IMUs (100 Hz), and raw triaxial acceleration data from eight official matches were analyzed. The measurement data were separated every 3 s, and a Fast Fourier Transform (FFT) was performed. After FFT, the Euclidean distances between the data when the players were in the stationary state and other states were calculated to classify the movements of the players using the k-means method. The data of the clustering numbers classified as the stationary state were eliminated after analyzing the movements of players by video filming the matches. After classification, the average Euclidean distances between the stationary state and other movements were calculated. Consequently, the results showed that the upward and downward directions of the raw data affected the classification. Using the methods of this study, it was also shown that the distribution of Euclidean distances differed from player to player. Our findings indicate that the method used in this study can be used to classify and characterize the movements of female collegiate soccer players.","PeriodicalId":20674,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology","volume":"49 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142266588","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 : 2024-09-19DOI: 10.1177/17543371241272843
Kazi Zahir Uddin, Hai Anh Nguyen, Thanh T Nguyen, Mitja Trkov, George Youssef, Behrad Koohbor
Midsoles are important components in footwear as they provide shock absorption and stability, thereby improving comfort and effectively preventing certain foot injuries. A strategically engineered midsole designed to mitigate plantar pressure can enhance athletic performance and comfort levels. Despite the importance of midsole design, the potential of using in-plane density gradation (deliberate variation of material density across the horizontal plane) in midsoles has been rarely explored. The present work investigated the effectiveness of in-plane density gradation in shoe midsoles using novel polyurea foams as the material candidate. Different polyurea foam densities, ranging from 95 to 350 kg/m2 were examined and tested to construct density-dependent correlative mathematical relations required for optimizing the midsole design for enhanced cushioning and reduced weight. This study combined mechanical testing and plantar pressure measurements to validate the efficacy of density-graded midsoles. The methodology introduced here is relevant to realistic walking conditions, ensured by biomechanical tests supplemented by digital image correlation analyses. An optimization framework was then created to allocate foam densities at certain plantar zones based on the required cushioning performance constrained by the local pressure. The optimization algorithm was specifically tailored to accommodate varying local pressures experienced by different areas of the foot. The optimization strategy in this study aimed at reducing the overall weight of the midsole while ensuring there were no compromises in cushioning efficacy or distribution of plantar pressure. The approach presented herein has the potential to be applied to a wide range of gait speeds and user-specific plantar pressure patterns.
{"title":"In-plane density gradation of shoe midsoles for optimal energy absorption performance","authors":"Kazi Zahir Uddin, Hai Anh Nguyen, Thanh T Nguyen, Mitja Trkov, George Youssef, Behrad Koohbor","doi":"10.1177/17543371241272843","DOIUrl":"https://doi.org/10.1177/17543371241272843","url":null,"abstract":"Midsoles are important components in footwear as they provide shock absorption and stability, thereby improving comfort and effectively preventing certain foot injuries. A strategically engineered midsole designed to mitigate plantar pressure can enhance athletic performance and comfort levels. Despite the importance of midsole design, the potential of using in-plane density gradation (deliberate variation of material density across the horizontal plane) in midsoles has been rarely explored. The present work investigated the effectiveness of in-plane density gradation in shoe midsoles using novel polyurea foams as the material candidate. Different polyurea foam densities, ranging from 95 to 350 kg/m<jats:sup>2</jats:sup> were examined and tested to construct density-dependent correlative mathematical relations required for optimizing the midsole design for enhanced cushioning and reduced weight. This study combined mechanical testing and plantar pressure measurements to validate the efficacy of density-graded midsoles. The methodology introduced here is relevant to realistic walking conditions, ensured by biomechanical tests supplemented by digital image correlation analyses. An optimization framework was then created to allocate foam densities at certain plantar zones based on the required cushioning performance constrained by the local pressure. The optimization algorithm was specifically tailored to accommodate varying local pressures experienced by different areas of the foot. The optimization strategy in this study aimed at reducing the overall weight of the midsole while ensuring there were no compromises in cushioning efficacy or distribution of plantar pressure. The approach presented herein has the potential to be applied to a wide range of gait speeds and user-specific plantar pressure patterns.","PeriodicalId":20674,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology","volume":"16 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142266585","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 : 2024-09-19DOI: 10.1177/17543371241272903
Benjamin P Clarke, Katherine Tomlinson, Amitha Karunakaran, Ahranee Canden, Janet Slatter, Tom Slatter, Matt Carré, Roger Lewis
The application of chalk (magnesium carbonate) in rock climbing is common practice as climbers attempt to improve their grip by removing moisture from their hands with the aim of increasing friction at the finger pad-rock interface. This novel work investigated the effectiveness of chalk as a friction modifier on four different rocks (sandstone, granite, dark limestone and light limestone) typically found in areas of the UK where the sport of climbing is undertaken, with varying surface roughness. The static coefficient of friction was measured for dry and wet fingertip conditions with and without chalk, under normal (‘grip’) forces of 5, 10 and 15 N. Results showed that the effectiveness of chalk as a friction modifier is dependent on a number of factors such as moisture level and the gradient of the asperity at the rock surface, however, in general chalk applied to dry fingertips had a more positive effect on the static coefficient of friction than in simulated sweaty conditions. During lab tests, chalk was also seen to be beneficial by making the static coefficient of friction more consistent across most test conditions. The results of this study, and the explanation of friction mechanisms involved, provides guidance for the use of chalk with consideration of the type of rock which is being climbed.
{"title":"The effectiveness of chalk as a friction modifier for finger pad contact with rocks of varying roughness","authors":"Benjamin P Clarke, Katherine Tomlinson, Amitha Karunakaran, Ahranee Canden, Janet Slatter, Tom Slatter, Matt Carré, Roger Lewis","doi":"10.1177/17543371241272903","DOIUrl":"https://doi.org/10.1177/17543371241272903","url":null,"abstract":"The application of chalk (magnesium carbonate) in rock climbing is common practice as climbers attempt to improve their grip by removing moisture from their hands with the aim of increasing friction at the finger pad-rock interface. This novel work investigated the effectiveness of chalk as a friction modifier on four different rocks (sandstone, granite, dark limestone and light limestone) typically found in areas of the UK where the sport of climbing is undertaken, with varying surface roughness. The static coefficient of friction was measured for dry and wet fingertip conditions with and without chalk, under normal (‘grip’) forces of 5, 10 and 15 N. Results showed that the effectiveness of chalk as a friction modifier is dependent on a number of factors such as moisture level and the gradient of the asperity at the rock surface, however, in general chalk applied to dry fingertips had a more positive effect on the static coefficient of friction than in simulated sweaty conditions. During lab tests, chalk was also seen to be beneficial by making the static coefficient of friction more consistent across most test conditions. The results of this study, and the explanation of friction mechanisms involved, provides guidance for the use of chalk with consideration of the type of rock which is being climbed.","PeriodicalId":20674,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology","volume":"49 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142266428","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 : 2024-09-19DOI: 10.1177/17543371241272749
Marine Dorsemaine, Catherine Masson, Serge Riveill, Nicolas Bailly, Pierre-Jean Arnoux
To protect skiers from the collisions with obstacles (CWOs), ski areas place padding on these obstacles. Padding behavior was previously experimentally investigated for few specific head impact conditions. The goal of this study is to numerically evaluate padding ability to reduce head injury risks in multiple scenarios of CWOs. A multibody model of a skier colliding with an obstacle was associated with a padding model, calibrated based on experimental tests. Different obstacle protections (unprotected, 15-, 20-, 30-cm thick padding), skier speeds, obstacle shapes and distances were investigated to model 3692 scenarios of CWOs. Head injury risks were evaluated based on HIC15 and maximal linear accelerations (Amax). Kruskal-Wallis tests were used to investigate the injury risks regarding the initial conditions, impact conditions and obstacle protection. These simulations resulted in high head impact speeds (30.4 ± 14.2 km/h). The padding modeled significantly reduced Amax (368 ± 275 g unprotected VS 215 ± 240 g with 15-cm thick padding) and severe injury risks ( p < 0.001). For low head impact speeds (<20 km/h), all pads were able to protect from severe injuries, whereas for moderate impact speeds (<40 km/h), the 30-cm thick padding offered better protection from severe injuries. However, even thick padding could not protect the skier model from high-speed impacts (>40 km/h). This study evaluated padding performances in various accident conditions and brought quantitative information for field evolutions regarding padding protection. These results constitute useful information to improve the padding standard and to design more efficient padding.
{"title":"Safety padding performances to protect from severe head injuries during alpine skiing","authors":"Marine Dorsemaine, Catherine Masson, Serge Riveill, Nicolas Bailly, Pierre-Jean Arnoux","doi":"10.1177/17543371241272749","DOIUrl":"https://doi.org/10.1177/17543371241272749","url":null,"abstract":"To protect skiers from the collisions with obstacles (CWOs), ski areas place padding on these obstacles. Padding behavior was previously experimentally investigated for few specific head impact conditions. The goal of this study is to numerically evaluate padding ability to reduce head injury risks in multiple scenarios of CWOs. A multibody model of a skier colliding with an obstacle was associated with a padding model, calibrated based on experimental tests. Different obstacle protections (unprotected, 15-, 20-, 30-cm thick padding), skier speeds, obstacle shapes and distances were investigated to model 3692 scenarios of CWOs. Head injury risks were evaluated based on HIC<jats:sub>15</jats:sub> and maximal linear accelerations (Amax). Kruskal-Wallis tests were used to investigate the injury risks regarding the initial conditions, impact conditions and obstacle protection. These simulations resulted in high head impact speeds (30.4 ± 14.2 km/h). The padding modeled significantly reduced Amax (368 ± 275 g unprotected VS 215 ± 240 g with 15-cm thick padding) and severe injury risks ( p < 0.001). For low head impact speeds (<20 km/h), all pads were able to protect from severe injuries, whereas for moderate impact speeds (<40 km/h), the 30-cm thick padding offered better protection from severe injuries. However, even thick padding could not protect the skier model from high-speed impacts (>40 km/h). This study evaluated padding performances in various accident conditions and brought quantitative information for field evolutions regarding padding protection. These results constitute useful information to improve the padding standard and to design more efficient padding.","PeriodicalId":20674,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology","volume":"12 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142266587","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 : 2024-09-19DOI: 10.1177/17543371241272860
Asier Gonzalez-Artetxe, Hugo Folgado, Asier Los Arcos
This study evaluated the consequences of repeating the same large-sided games, playing free or conditioned, during several training sessions on young footballers’ tactical and conditional performances and their variabilities. Thirty-two U14 and U16 developmental male footballers participated in the study. Both teams, divided into two balanced groups (free play and conditioned), faced each other during three eight-a-side games (seven vs seven, plus goalkeepers) during three training sessions. The free-play groups played as they pleased, while the conditioned groups played the games conditioned by tactical instructions. Tactical performance was assessed by central tendency and normalized approximate entropy measures of the distance of each player to the team centroid (m) and the distance of each player to their mean position (m), while the conditional performance was assessed by total distance (m) and walking, jogging, running, and sprinting distances traveled (m), and number of accelerations and decelerations performed. Whereas players’ average tactical and conditional responses scarcely varied between sessions, inter- and intra-player variabilities were always considerable (coefficient of variation >10%) regardless of the task conditions and the age group. In addition, all footballers’ conditional variability was substantially higher at faster speeds (jogging, running, and sprinting distances) than at slower ones (total distance and walking distance traveled), and for accelerations and decelerations performed. Implementing large-sided games with or without tactical instructions may be an appropriate training strategy to ensure stable and constant average responses for the team. Nevertheless, academy football coaches should bear in mind and manage the variability between and within players.
{"title":"Effects of training repetition on young footballers’ tactical and physical performances: free and conditioned large-sided games","authors":"Asier Gonzalez-Artetxe, Hugo Folgado, Asier Los Arcos","doi":"10.1177/17543371241272860","DOIUrl":"https://doi.org/10.1177/17543371241272860","url":null,"abstract":"This study evaluated the consequences of repeating the same large-sided games, playing free or conditioned, during several training sessions on young footballers’ tactical and conditional performances and their variabilities. Thirty-two U14 and U16 developmental male footballers participated in the study. Both teams, divided into two balanced groups (free play and conditioned), faced each other during three eight-a-side games (seven vs seven, plus goalkeepers) during three training sessions. The free-play groups played as they pleased, while the conditioned groups played the games conditioned by tactical instructions. Tactical performance was assessed by central tendency and normalized approximate entropy measures of the distance of each player to the team centroid (m) and the distance of each player to their mean position (m), while the conditional performance was assessed by total distance (m) and walking, jogging, running, and sprinting distances traveled (m), and number of accelerations and decelerations performed. Whereas players’ average tactical and conditional responses scarcely varied between sessions, inter- and intra-player variabilities were always considerable (coefficient of variation >10%) regardless of the task conditions and the age group. In addition, all footballers’ conditional variability was substantially higher at faster speeds (jogging, running, and sprinting distances) than at slower ones (total distance and walking distance traveled), and for accelerations and decelerations performed. Implementing large-sided games with or without tactical instructions may be an appropriate training strategy to ensure stable and constant average responses for the team. Nevertheless, academy football coaches should bear in mind and manage the variability between and within players.","PeriodicalId":20674,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology","volume":"16 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142266426","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 : 2024-09-19DOI: 10.1177/17543371241272889
Matic Sašek, Oskar Cvjetičanin, Nejc Šarabon
The hydraulic resistance device (HRD), a state-of-the-art device developed primarily for resisted sprint training, lacks exploration of its force-generating properties. This technical note aims to evaluate these properties in vitro. In a laboratory experiment, the HRD was pulled with a motorised winch at four speeds (1–4 m s−1) and 12 different HRD resistance levels (low, medium and high). The resistance force induced by the HRD was measured using a force plate mounted under the device, and calculated as mean horizontal force produced at a constant pulling speed. Resistance force repeatability between pulling speeds at specific resistance levels was assessed using the coefficient of variation (CV) whereas the intraclass correlation coefficient (ICC3,1) was calculated to determine the consistency. A linear regression model quantified resistance force as a function of HRD resistance level. Accuracy of the model was assessed using root mean square error (RMSE). Across 12 resistance levels, the HRD produced resistance forces ranging from 22.57 ± 4.84 to 164.57 ± 4.84 N. The CV decreased from 21.5% at the lowest resistance to 0.4% at the highest. The HRD produced resistance force with high consistency (ICC3,1 CI = 0.990–0.999). The linear regression model showed a near-perfect fit ( R2 = 0.99) and predicted resistance force more accurately at medium and high resistance (RMSE range = 0.97–4.57 N). The HRD provides favourable force-generating properties for resisted sprint training and testing, warranting further studies on its exploration in vivo.
{"title":"In vitro quantification of the resistance force properties of a hydraulic resistance device designed for sprinting","authors":"Matic Sašek, Oskar Cvjetičanin, Nejc Šarabon","doi":"10.1177/17543371241272889","DOIUrl":"https://doi.org/10.1177/17543371241272889","url":null,"abstract":"The hydraulic resistance device (HRD), a state-of-the-art device developed primarily for resisted sprint training, lacks exploration of its force-generating properties. This technical note aims to evaluate these properties in vitro. In a laboratory experiment, the HRD was pulled with a motorised winch at four speeds (1–4 m s<jats:sup>−1</jats:sup>) and 12 different HRD resistance levels (low, medium and high). The resistance force induced by the HRD was measured using a force plate mounted under the device, and calculated as mean horizontal force produced at a constant pulling speed. Resistance force repeatability between pulling speeds at specific resistance levels was assessed using the coefficient of variation (CV) whereas the intraclass correlation coefficient (ICC<jats:sub>3,1</jats:sub>) was calculated to determine the consistency. A linear regression model quantified resistance force as a function of HRD resistance level. Accuracy of the model was assessed using root mean square error (RMSE). Across 12 resistance levels, the HRD produced resistance forces ranging from 22.57 ± 4.84 to 164.57 ± 4.84 N. The CV decreased from 21.5% at the lowest resistance to 0.4% at the highest. The HRD produced resistance force with high consistency (ICC<jats:sub>3,1</jats:sub> CI = 0.990–0.999). The linear regression model showed a near-perfect fit ( R<jats:sup>2</jats:sup> = 0.99) and predicted resistance force more accurately at medium and high resistance (RMSE range = 0.97–4.57 N). The HRD provides favourable force-generating properties for resisted sprint training and testing, warranting further studies on its exploration in vivo.","PeriodicalId":20674,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology","volume":"197 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142266589","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 : 2024-09-19DOI: 10.1177/17543371241272789
Stuart M Chesher, Simon M Rosalie, Dale W Chapman, Paula C Charlton, Fleur ECA van Rens, Kevin J Netto
The objective of this research was to validate a single, trunk-mounted wearable sensor (Optimeye S5, Catapult Australia, Melbourne) to measure the cadence of swimming strokes, cycling pedals and running strides in a triathlon. While similar validations have been performed in swimming and running, it is a novel application in cycling, and thus, across a whole triathlon. Seven triathletes were recruited to participate in a sprint distance triathlon which was filmed and simultaneously measured by a single, trunk-mounted wearable sensor. To validate the wearable sensor, individual swimming strokes, cycling pedal strokes and running strides were manually counted by viewing the wearable sensor data and video footage. While analysing cycling data, changes in cycling subtask performances were noticed, thus, a secondary analysis in cycling was conducted to investigate. The 95% limits of agreement analysis indicated the sensor validly measured swimming strokes (mean bias = −0.034 strokes), cycling pedal strokes (mean bias = −0.09 strokes) and running strides (mean bias = 0.00 strides) with minimal to no bias ( p > 0.05). Further analysis of cycling revealed the wearable sensor is an acceptably valid tool to measure the duration of out of saddle riding (mean bias = 0.08 s), however, significant differences in the duration of in saddle riding (mean bias = −0.5 s) and coasting were identified (mean bias = 0.39 s). A single trunk mounted wearable sensor is a valid tool to measure movement cadence in a triathlon, however, further validation is required to generate a full understanding of cycling subtask performances.
{"title":"A single trunk-mounted wearable sensor to measure motor performance in triathletes during competition","authors":"Stuart M Chesher, Simon M Rosalie, Dale W Chapman, Paula C Charlton, Fleur ECA van Rens, Kevin J Netto","doi":"10.1177/17543371241272789","DOIUrl":"https://doi.org/10.1177/17543371241272789","url":null,"abstract":"The objective of this research was to validate a single, trunk-mounted wearable sensor (Optimeye S5, Catapult Australia, Melbourne) to measure the cadence of swimming strokes, cycling pedals and running strides in a triathlon. While similar validations have been performed in swimming and running, it is a novel application in cycling, and thus, across a whole triathlon. Seven triathletes were recruited to participate in a sprint distance triathlon which was filmed and simultaneously measured by a single, trunk-mounted wearable sensor. To validate the wearable sensor, individual swimming strokes, cycling pedal strokes and running strides were manually counted by viewing the wearable sensor data and video footage. While analysing cycling data, changes in cycling subtask performances were noticed, thus, a secondary analysis in cycling was conducted to investigate. The 95% limits of agreement analysis indicated the sensor validly measured swimming strokes (mean bias = −0.034 strokes), cycling pedal strokes (mean bias = −0.09 strokes) and running strides (mean bias = 0.00 strides) with minimal to no bias ( p > 0.05). Further analysis of cycling revealed the wearable sensor is an acceptably valid tool to measure the duration of out of saddle riding (mean bias = 0.08 s), however, significant differences in the duration of in saddle riding (mean bias = −0.5 s) and coasting were identified (mean bias = 0.39 s). A single trunk mounted wearable sensor is a valid tool to measure movement cadence in a triathlon, however, further validation is required to generate a full understanding of cycling subtask performances.","PeriodicalId":20674,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology","volume":"7 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142266427","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 : 2024-09-19DOI: 10.1177/17543371241277017
Recep Fatih Kayhan, Ali Kizile, Tuba Kizilet
The aim of this study was to develop a valid and reliable video-based test to analyze the decision-making performance of Turkish football referees. Twenty-two divisional and fifteen local football referees affiliated to the Turkish Football Federation participated in the study. Using SuperLab 5 software and a Cedrus response pad, a test consisting of 20 video clips to be answered as yellow card, red card, and no card was designed. The referees watched the video clips in sequence and made a decision by pressing the button assigned for the decision of their choice. After each decision, the next video automatically appeared on the screen. The protocol was repeated at 10-day intervals for validity and reliability analyses. Content validity and construct validity were used for validity. Cohen’s kappa statistic and intraclass correlation coefficient were used for reliability. Expert referees confirmed content validity by assessing the degree to which the video clips reflected actual match conditions (CVR > 0.80). Difference analysis results showed that the test was able to discriminate the performance of the referees according to their level of performance, thus establishing construct validity ( p < 0.05). High Cohen kappa values indicated that the video clips were reliable ( K = 0.84). High ICC values indicated that the scoring scale was reliable and consistently assessed the decision-making performance of the referees (ICC = between 0.81 and 0.95; CV = between 0.74 and 4.49; MDC = between 0.02 and 1.45; SEM = between 0.01 and 0.52). In conclusion, the fact that the video-based decision-making test meets the validity and reliability criteria shows that the decision-making performance of the referees can be measured accurately and consistently.
{"title":"Development of a video-based test for assessing decision-making proficiency in football referees","authors":"Recep Fatih Kayhan, Ali Kizile, Tuba Kizilet","doi":"10.1177/17543371241277017","DOIUrl":"https://doi.org/10.1177/17543371241277017","url":null,"abstract":"The aim of this study was to develop a valid and reliable video-based test to analyze the decision-making performance of Turkish football referees. Twenty-two divisional and fifteen local football referees affiliated to the Turkish Football Federation participated in the study. Using SuperLab 5 software and a Cedrus response pad, a test consisting of 20 video clips to be answered as yellow card, red card, and no card was designed. The referees watched the video clips in sequence and made a decision by pressing the button assigned for the decision of their choice. After each decision, the next video automatically appeared on the screen. The protocol was repeated at 10-day intervals for validity and reliability analyses. Content validity and construct validity were used for validity. Cohen’s kappa statistic and intraclass correlation coefficient were used for reliability. Expert referees confirmed content validity by assessing the degree to which the video clips reflected actual match conditions (CVR > 0.80). Difference analysis results showed that the test was able to discriminate the performance of the referees according to their level of performance, thus establishing construct validity ( p < 0.05). High Cohen kappa values indicated that the video clips were reliable ( K = 0.84). High ICC values indicated that the scoring scale was reliable and consistently assessed the decision-making performance of the referees (ICC = between 0.81 and 0.95; CV = between 0.74 and 4.49; MDC = between 0.02 and 1.45; SEM = between 0.01 and 0.52). In conclusion, the fact that the video-based decision-making test meets the validity and reliability criteria shows that the decision-making performance of the referees can be measured accurately and consistently.","PeriodicalId":20674,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology","volume":"99 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142266586","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 : 2024-08-29DOI: 10.1177/17543371241276249
Gibson Moreira Praça, Leandro Henrique Albuquerque Brandão, Guilherme de Oliveira Santos Silva, Pedro Henrique de Almeida Oliveira, Varley Teoldo da Costa, Guilherme Sousa Pinheiro
This study aimed to compare position-based variables between winning, losing, and drawing teams and to identify which among these variables would better predict the goal difference in the 2021–2022 German Bundesliga. The dataset comprised 275 official games, monitored through a semi-automatic camera system. For each game, players’ and ball’s positions were captured and exported in 10 Hz. Position-based variables comprised teams’ length, width, length per width ratio (LPWratio), stretching index, and near-the-ball space control in both offensive and defensive phases, as well as in the first and the second halves. Data were compared between the game outcomes using a Generalized Linear Model. Results indicated that winning teams in the Bundesliga tend to approach the first half of the game by expanding the field during the offensive phase (evidenced by a higher offensive width and stretching index), pressing high during the defensive phase (manifested through a greater defensive length), and exerting control over the space in the second half by concentrating players near the ball (indicated by higher near-the-ball space control). Differences between halves indicate that teams must be able to adapt their tactics during the game to succeed in the competition.
{"title":"Positioning to win: Key position-based performance indicators in elite soccer","authors":"Gibson Moreira Praça, Leandro Henrique Albuquerque Brandão, Guilherme de Oliveira Santos Silva, Pedro Henrique de Almeida Oliveira, Varley Teoldo da Costa, Guilherme Sousa Pinheiro","doi":"10.1177/17543371241276249","DOIUrl":"https://doi.org/10.1177/17543371241276249","url":null,"abstract":"This study aimed to compare position-based variables between winning, losing, and drawing teams and to identify which among these variables would better predict the goal difference in the 2021–2022 German Bundesliga. The dataset comprised 275 official games, monitored through a semi-automatic camera system. For each game, players’ and ball’s positions were captured and exported in 10 Hz. Position-based variables comprised teams’ length, width, length per width ratio (LPWratio), stretching index, and near-the-ball space control in both offensive and defensive phases, as well as in the first and the second halves. Data were compared between the game outcomes using a Generalized Linear Model. Results indicated that winning teams in the Bundesliga tend to approach the first half of the game by expanding the field during the offensive phase (evidenced by a higher offensive width and stretching index), pressing high during the defensive phase (manifested through a greater defensive length), and exerting control over the space in the second half by concentrating players near the ball (indicated by higher near-the-ball space control). Differences between halves indicate that teams must be able to adapt their tactics during the game to succeed in the competition.","PeriodicalId":20674,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology","volume":"60 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142221040","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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