Pub Date : 2023-12-30DOI: 10.1177/17543371231211074
Guangwu Sun, Shiyuan Liu, Xiaona Chen, Hong Xie
Breasts can move considerably when women are active, which can sometimes be uncomfortable. Many studies have measured breast movement by a camera recording the movement of multiple markers attached to the breast. However, an excessive number of markers may hinder the subject’s movement. Additionally, camera images cannot readily distinguish closely arranged LED markers owing to interference of light from the markers. Therefore, it is necessary to develop a numerical model to minimize experimental limitations. The present numerical model was developed based on the Lagrange method to enable simultaneous prediction of the movement of multiple positions on the breast during successional vertical jumps. The modeling results revealed the nipple demonstrated a larger displacement (average displacement ≈ 52.73 mm) than other marker positions during successive jumps. The breast top showed lower displacement (average displacement ≈ 46.18 mm) than other marker positions. The model also revealed the force variation on the breast during a jump. The whole breast movement was dependent on a combination of multiple forces. The viscoelastic force provided resistance to breast deformation. The restoring force drove the breast upward, while the gravity force pulled it down. The model synchronously calculated the displacements of more than 30 positions on the breast, then exported the vertical movement path of the whole breast. The model can only predict the vertical displacement and force; it still needs to be improved in other directions.
{"title":"Female breast motion during exercise based on the Lagrange method","authors":"Guangwu Sun, Shiyuan Liu, Xiaona Chen, Hong Xie","doi":"10.1177/17543371231211074","DOIUrl":"https://doi.org/10.1177/17543371231211074","url":null,"abstract":"Breasts can move considerably when women are active, which can sometimes be uncomfortable. Many studies have measured breast movement by a camera recording the movement of multiple markers attached to the breast. However, an excessive number of markers may hinder the subject’s movement. Additionally, camera images cannot readily distinguish closely arranged LED markers owing to interference of light from the markers. Therefore, it is necessary to develop a numerical model to minimize experimental limitations. The present numerical model was developed based on the Lagrange method to enable simultaneous prediction of the movement of multiple positions on the breast during successional vertical jumps. The modeling results revealed the nipple demonstrated a larger displacement (average displacement ≈ 52.73 mm) than other marker positions during successive jumps. The breast top showed lower displacement (average displacement ≈ 46.18 mm) than other marker positions. The model also revealed the force variation on the breast during a jump. The whole breast movement was dependent on a combination of multiple forces. The viscoelastic force provided resistance to breast deformation. The restoring force drove the breast upward, while the gravity force pulled it down. The model synchronously calculated the displacements of more than 30 positions on the breast, then exported the vertical movement path of the whole breast. The model can only predict the vertical displacement and force; it still needs to be improved in other directions.","PeriodicalId":20674,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology","volume":" 15","pages":""},"PeriodicalIF":1.5,"publicationDate":"2023-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139141516","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 : 2023-12-09DOI: 10.1177/17543371231213780
Mikael Swarén, M. Fahlstedt
The purpose of this study was to investigate if the impact attenuation properties of ice hockey helmets change after being used for one season in a professional ice hockey league. Eighteen helmets from a male team and 10 helmets from a female team were compared to 13 new helmets. Every helmet was impact tested three times for two impact locations, side and front. The median peak linear acceleration for all front impacts were significantly higher ( p < 0.05) for the helmets from the female team compared to the helmets from the male team. Compared to the new helmets, both men’s and women’s helmets had significantly lower median peak angular acceleration ( p < 0.01) and peak angular velocity ( p< 0.001). For side impacts, the women’s helmets had significantly higher peak linear acceleration compared to the men’s and new helmets ( p < 0.001). Both men’s and women’s helmets had significantly higher peak angular acceleration compared to the new helmets ( p < 0.001), and women’s helmets also had significantly higher peak angular acceleration compared to men’s helmets. Compared to men’s and new helmets, the results show that women’s helmets have worse impact attenuation properties after one season. However, all used helmets satisfied the passing threshold for test standards and the differences in calculated injury risk were small. This information may assist in establishing recommendations for the expected lifetime usage for ice hockey helmets and support manufacturers to develop safer ice hockey helmets.
{"title":"How are the impact attenuation properties of men’s and women’s helmets affected after one season in professional ice hockey?","authors":"Mikael Swarén, M. Fahlstedt","doi":"10.1177/17543371231213780","DOIUrl":"https://doi.org/10.1177/17543371231213780","url":null,"abstract":"The purpose of this study was to investigate if the impact attenuation properties of ice hockey helmets change after being used for one season in a professional ice hockey league. Eighteen helmets from a male team and 10 helmets from a female team were compared to 13 new helmets. Every helmet was impact tested three times for two impact locations, side and front. The median peak linear acceleration for all front impacts were significantly higher ( p < 0.05) for the helmets from the female team compared to the helmets from the male team. Compared to the new helmets, both men’s and women’s helmets had significantly lower median peak angular acceleration ( p < 0.01) and peak angular velocity ( p< 0.001). For side impacts, the women’s helmets had significantly higher peak linear acceleration compared to the men’s and new helmets ( p < 0.001). Both men’s and women’s helmets had significantly higher peak angular acceleration compared to the new helmets ( p < 0.001), and women’s helmets also had significantly higher peak angular acceleration compared to men’s helmets. Compared to men’s and new helmets, the results show that women’s helmets have worse impact attenuation properties after one season. However, all used helmets satisfied the passing threshold for test standards and the differences in calculated injury risk were small. This information may assist in establishing recommendations for the expected lifetime usage for ice hockey helmets and support manufacturers to develop safer ice hockey helmets.","PeriodicalId":20674,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology","volume":"2 7","pages":""},"PeriodicalIF":1.5,"publicationDate":"2023-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138585661","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 : 2023-12-04DOI: 10.1177/17543371231213904
A. Gentilin
Prediction of maximal oxygen consumption (VO2max) and maximal workload capacity (MWC) through submaximal exercise tests is an important topic for sports sciences. Numerous studies highlighted the predictive power of submaximal heart rate (HR) and oxygen consumption (VO2) in predicting VO2max and MWC. The challenge is achieving the best possible precision and accuracy by identifying the best predictors and regression models. This project assessed the performance of different indexes along with machine learning regression models to estimate VO2max and MWC. Predictors consisted of biodata (age, weight, and height) along with different combinations of change-scores of HR and VO2 between 0–50 Watts, 50–65 Watts, and 65–80 Watts (Δ0–50, Δ50–65, and Δ65–80, respectively). The use of biodata + HR Δ50–65 + HR Δ65-80 via a Squared Exponential Gaussian Process Regression model resulted in the best performance in predicting VO2max, while the use of biodata + HR Δ0–50 via a Robust Linear Regression model resulted in the best performance in predicting MWC. These results suggest that information provided by HR only during submaximal exercise offers the best predictive mean for estimating VO2max and MWC, while the use of VO2 changes or its addition along with HR changes does not improve predictions. Moreover, different predictors need to be selected for the best estimation of VO2max and MWC. Change-scores refer to absolute value changes, providing information to develop athlete assessment protocols through standardized workloads. These results show practical applicability for sports assessments to be performed indirectly, rapidly, sub-maximally, and through the simple measurement of HR.
{"title":"The informative power of heart rate along with machine learning regression models to predict maximal oxygen consumption and maximal workload capacity","authors":"A. Gentilin","doi":"10.1177/17543371231213904","DOIUrl":"https://doi.org/10.1177/17543371231213904","url":null,"abstract":"Prediction of maximal oxygen consumption (VO2max) and maximal workload capacity (MWC) through submaximal exercise tests is an important topic for sports sciences. Numerous studies highlighted the predictive power of submaximal heart rate (HR) and oxygen consumption (VO2) in predicting VO2max and MWC. The challenge is achieving the best possible precision and accuracy by identifying the best predictors and regression models. This project assessed the performance of different indexes along with machine learning regression models to estimate VO2max and MWC. Predictors consisted of biodata (age, weight, and height) along with different combinations of change-scores of HR and VO2 between 0–50 Watts, 50–65 Watts, and 65–80 Watts (Δ0–50, Δ50–65, and Δ65–80, respectively). The use of biodata + HR Δ50–65 + HR Δ65-80 via a Squared Exponential Gaussian Process Regression model resulted in the best performance in predicting VO2max, while the use of biodata + HR Δ0–50 via a Robust Linear Regression model resulted in the best performance in predicting MWC. These results suggest that information provided by HR only during submaximal exercise offers the best predictive mean for estimating VO2max and MWC, while the use of VO2 changes or its addition along with HR changes does not improve predictions. Moreover, different predictors need to be selected for the best estimation of VO2max and MWC. Change-scores refer to absolute value changes, providing information to develop athlete assessment protocols through standardized workloads. These results show practical applicability for sports assessments to be performed indirectly, rapidly, sub-maximally, and through the simple measurement of HR.","PeriodicalId":20674,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology","volume":"31 12","pages":""},"PeriodicalIF":1.5,"publicationDate":"2023-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138602483","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 : 2023-12-04DOI: 10.1177/17543371231213772
Wei-Han Chen, Chi-Hsien Chen, Wen-Wen Yang, Gin-Yun Lin, Wei-Chun Hsu, T. Shiang, Chiang Liu
This study compared the ground reaction force (GRF), GRF ratio, and contact time between badminton shoes without and with a lateral forefoot wedge sole during lunges in three directions. Fifteen collegiate athletes wore forefoot wedge shoes (5° incline) and control shoes without a lateral forefoot wedge sole (in random order) and performed three typical badminton lunge movements (forward, lateral, and backward directions). A total of nine GRF, GRF ratio, and contact time parameters were analyzed. A paired t test was performed to assess the differences between two shoes. The significance level was set at p < 0.0056 (0.05/9) based on Bonferroni correction to avoid chances of type 1 errors. In the forward lunge, the forefoot wedge shoes resulted in a significantly higher average vertical ground reaction force (GRFv, 3.9%), average horizontal GRF (GRFh, 7.8%) in the braking phase and higher average GRFh (3.9%) in the propulsion phase than the control shoes. In the lateral lunge, the forefoot wedge shoes resulted in a significantly shorter total contact time (−4.6%) than the control shoes in the backward lunge, the forefoot wedge shoes resulted in a significantly higher GRFh to GRFv ratio (6.4%) in the braking phase compared with the control shoes. Thus, shoes with a lateral forefoot wedge sole can effectively enhance mechanical performance in direction changes during forward and backward badminton lunges, and shorter the contact time during lateral badminton lunges. Shoes with a lateral forefoot wedge sole can be considered when designing athletic footwear.
{"title":"Comparison of ground reaction force and contact time during various-direction lunges between badminton shoes without and with a lateral forefoot wedge sole","authors":"Wei-Han Chen, Chi-Hsien Chen, Wen-Wen Yang, Gin-Yun Lin, Wei-Chun Hsu, T. Shiang, Chiang Liu","doi":"10.1177/17543371231213772","DOIUrl":"https://doi.org/10.1177/17543371231213772","url":null,"abstract":"This study compared the ground reaction force (GRF), GRF ratio, and contact time between badminton shoes without and with a lateral forefoot wedge sole during lunges in three directions. Fifteen collegiate athletes wore forefoot wedge shoes (5° incline) and control shoes without a lateral forefoot wedge sole (in random order) and performed three typical badminton lunge movements (forward, lateral, and backward directions). A total of nine GRF, GRF ratio, and contact time parameters were analyzed. A paired t test was performed to assess the differences between two shoes. The significance level was set at p < 0.0056 (0.05/9) based on Bonferroni correction to avoid chances of type 1 errors. In the forward lunge, the forefoot wedge shoes resulted in a significantly higher average vertical ground reaction force (GRFv, 3.9%), average horizontal GRF (GRFh, 7.8%) in the braking phase and higher average GRFh (3.9%) in the propulsion phase than the control shoes. In the lateral lunge, the forefoot wedge shoes resulted in a significantly shorter total contact time (−4.6%) than the control shoes in the backward lunge, the forefoot wedge shoes resulted in a significantly higher GRFh to GRFv ratio (6.4%) in the braking phase compared with the control shoes. Thus, shoes with a lateral forefoot wedge sole can effectively enhance mechanical performance in direction changes during forward and backward badminton lunges, and shorter the contact time during lateral badminton lunges. Shoes with a lateral forefoot wedge sole can be considered when designing athletic footwear.","PeriodicalId":20674,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology","volume":"20 26","pages":""},"PeriodicalIF":1.5,"publicationDate":"2023-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138601654","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}
Elo ratings-based methods, including the recently proposed Weighted Elo method, have been found to perform well when forecasting tennis match results, however, whether they can outperform machine learning (ML) has not been established. In this study, a comparative evaluation of the two types of methods is conducted using the Sports Result Prediction CRISP-DM experimental framework. The first full year of mens ATP tennis data (2006), in a dataset containing matches from 2005 to 2020, was set to be the initial training set and 1 year of data was incrementally added to this set to predict 14 test years, from 2007 to 2020. Features were ranked based on their average rank across five feature selection techniques. It was found that, of the five ML models, Alternating Decision Trees (ADTrees) and Logistic Regression achieved higher accuracies than Elo ratings and similar accuracies to predictions derived from betting odds. Furthermore, ADTrees show potential in this domain, with solid performance achieved with an interpretable decision tree that allows for variation in the average betting odds difference threshold.
{"title":"A comparative evaluation of Elo ratings- and machine learning-based methods for tennis match result prediction","authors":"Rory Bunker, Calvin Yeung, Teo Susnjak, Chester Espie, Keisuke Fujii","doi":"10.1177/17543371231212235","DOIUrl":"https://doi.org/10.1177/17543371231212235","url":null,"abstract":"Elo ratings-based methods, including the recently proposed Weighted Elo method, have been found to perform well when forecasting tennis match results, however, whether they can outperform machine learning (ML) has not been established. In this study, a comparative evaluation of the two types of methods is conducted using the Sports Result Prediction CRISP-DM experimental framework. The first full year of mens ATP tennis data (2006), in a dataset containing matches from 2005 to 2020, was set to be the initial training set and 1 year of data was incrementally added to this set to predict 14 test years, from 2007 to 2020. Features were ranked based on their average rank across five feature selection techniques. It was found that, of the five ML models, Alternating Decision Trees (ADTrees) and Logistic Regression achieved higher accuracies than Elo ratings and similar accuracies to predictions derived from betting odds. Furthermore, ADTrees show potential in this domain, with solid performance achieved with an interpretable decision tree that allows for variation in the average betting odds difference threshold.","PeriodicalId":20674,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology","volume":" 638","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135186228","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 : 2023-11-07DOI: 10.1177/17543371231208847
Andreu Sastre-Munar, Natalia Romero-Franco
Athletes and coaches often normalize injuries and pain to gain sports performance. Consistent supervision of workload and psycho-physiological aspects may prevent injuries and maximize performance, mainly integrating insights from healthcare and sports. Although these aspects could be facilitated through smartphone devices, no smartphone applications (apps) have been designed to monitor these aspects of the athlete experience. This study aimed to evaluate the capability of an app to collect sports and health data and identify areas for app enhancement. An observational study was designed to test the app (named: SaluTrack). Eleven young athletes, eight males and three females, were invited to participate. During 5 weeks, all participants used the app to complete four questionnaires periodically: wellness, pain, urinary incontinence (UI), and catastrophizing. The questionnaires were completed by 90.9% of participating athletes periodically. Regarding the wellness questionnaire, athletes responded with 10.94 ± 4.37 as the average rating. Regarding pain, all athletes who completed the questionnaire affirmed to have pain (3.63 ± 1.73), the knee being the anatomical region most affected (26.67%). Also, 27.27% of athletes affirmed to have UI. Regarding catastrophizing level, athletes showed 8.91 ± 9.02 points. Regarding qualitative feedback from athletes, we received three comments, all positive aspects gained from using this tool. SaluTrack showed to be an appropriate app to easily collect sports and health data from athletes related to wellness, pain, UI, and catastrophizing. This methodology is useful for weekly monitoring of potential injury risk and to improve coaching staff’s communication with athletes.
{"title":"SALUTRACK: A smartphone application to evaluate and monitor injuries and health problems in athletes from the Balearic Islands","authors":"Andreu Sastre-Munar, Natalia Romero-Franco","doi":"10.1177/17543371231208847","DOIUrl":"https://doi.org/10.1177/17543371231208847","url":null,"abstract":"Athletes and coaches often normalize injuries and pain to gain sports performance. Consistent supervision of workload and psycho-physiological aspects may prevent injuries and maximize performance, mainly integrating insights from healthcare and sports. Although these aspects could be facilitated through smartphone devices, no smartphone applications (apps) have been designed to monitor these aspects of the athlete experience. This study aimed to evaluate the capability of an app to collect sports and health data and identify areas for app enhancement. An observational study was designed to test the app (named: SaluTrack). Eleven young athletes, eight males and three females, were invited to participate. During 5 weeks, all participants used the app to complete four questionnaires periodically: wellness, pain, urinary incontinence (UI), and catastrophizing. The questionnaires were completed by 90.9% of participating athletes periodically. Regarding the wellness questionnaire, athletes responded with 10.94 ± 4.37 as the average rating. Regarding pain, all athletes who completed the questionnaire affirmed to have pain (3.63 ± 1.73), the knee being the anatomical region most affected (26.67%). Also, 27.27% of athletes affirmed to have UI. Regarding catastrophizing level, athletes showed 8.91 ± 9.02 points. Regarding qualitative feedback from athletes, we received three comments, all positive aspects gained from using this tool. SaluTrack showed to be an appropriate app to easily collect sports and health data from athletes related to wellness, pain, UI, and catastrophizing. This methodology is useful for weekly monitoring of potential injury risk and to improve coaching staff’s communication with athletes.","PeriodicalId":20674,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology","volume":"299 8","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135475201","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 review, focussed on transmission efficiency and wear in cycling, presents existing friction measuring devices. It discusses their pros and cons and compares the lubrication regime they are in to the ones determined for elite cycling. Finally, it addresses technical guidelines for measuring friction forces from the transmission ( F t ). F t depend on normal load and coefficient of friction (µ). Indeed, these factors are influenced by chain tension, alignment and velocity, sprocket size, lubricants and contamination. Such parameters also have an impact on lubrication regime which influences µ. To characterise F t , measuring devices were developed. Forty devices were classified in five categories, ranging from those closest to ecological conditions to the most specific ones. Full transmission (FTR) and single speed rigs (SSR) results can be extrapolated into real cycling, although they are less accurate as they involve more elements. Dedicated rigs engender high precision measurements on precise phenomena. All lubrication regimes are encountered in elite cycling, which is in good accordance with most of the testing conditions presented in this review, especially FTR and SSR. If Boundary and Mixed regimes are unavoidable due to the reciprocating movements of the chain elements, they should be limited. The Elasto-Hydrodynamic regime is on target as it provides low µ and wear. In conclusion, the closer the measure is to real cycling, the higher the variability. Inversely, dedicated rigs are accurate but less representative of complete transmissions. Technology improvements now make FTR and SSR reliable enough to measure small differences, along with a strong protocol.
{"title":"Tribological devices in cycling: A review","authors":"Rémi Aubert, Xavier Roizard, Frédéric Grappe, Fabrice Lallemand","doi":"10.1177/17543371231202562","DOIUrl":"https://doi.org/10.1177/17543371231202562","url":null,"abstract":"This review, focussed on transmission efficiency and wear in cycling, presents existing friction measuring devices. It discusses their pros and cons and compares the lubrication regime they are in to the ones determined for elite cycling. Finally, it addresses technical guidelines for measuring friction forces from the transmission ( F t ). F t depend on normal load and coefficient of friction (µ). Indeed, these factors are influenced by chain tension, alignment and velocity, sprocket size, lubricants and contamination. Such parameters also have an impact on lubrication regime which influences µ. To characterise F t , measuring devices were developed. Forty devices were classified in five categories, ranging from those closest to ecological conditions to the most specific ones. Full transmission (FTR) and single speed rigs (SSR) results can be extrapolated into real cycling, although they are less accurate as they involve more elements. Dedicated rigs engender high precision measurements on precise phenomena. All lubrication regimes are encountered in elite cycling, which is in good accordance with most of the testing conditions presented in this review, especially FTR and SSR. If Boundary and Mixed regimes are unavoidable due to the reciprocating movements of the chain elements, they should be limited. The Elasto-Hydrodynamic regime is on target as it provides low µ and wear. In conclusion, the closer the measure is to real cycling, the higher the variability. Inversely, dedicated rigs are accurate but less representative of complete transmissions. Technology improvements now make FTR and SSR reliable enough to measure small differences, along with a strong protocol.","PeriodicalId":20674,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology","volume":"1 3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135773383","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 : 2023-11-04DOI: 10.1177/17543371231208401
Alfonso Castillo-Rodríguez, Wanesa Onetti-Onetti, Filipe Manuel Clemente, Francisco Tomás González-Fernández
The aim of this study was to define and classify the different physical and physiological performance metrics on national and non-national soccer referees (SRs) through GPS technology. Sixty SRs (age: 28.9 ± 4.9 years; weight: 70.2 ± 8.0 kg; height: 175.7 ± 5.5 cm) were tested using the 18 Hz global positioning system (GPS) (WimuPro, Realtrack, Almería, Spain). An exploratory factor analysis was performed using principal component analysis (PCA) on performance indicators with orthogonal rotation (VariMax). Thirteen metrics (total distance, distance covered at different speeds, maximum heart rate, and heart rate recorded in different zones) were integrated in three principal components, activation (PCA1), recovery (PCA2), and high intensity (PCA3). They represented 86% and 89% of total explained variance of the competition performance in national and non-national SRs, respectively. Distance covered at very high speed and heart rate between 80% and 89.9% of the maximum integrated the high-intensity principal component and were higher in non-national SRs. The main finding of this study was that it defined for the first time in the scientific literature the main components that discriminate physical performance between national and non-national referees, where high intensity metrics have greater weight in non-national referees. In addition, GPS technology together with PCA analysis were presented as useful methods to discriminate the most representative physical and physiological performance metrics in sports competition in SRs.
{"title":"Principal components approach of physiological and physical metrics collected through GPS technology in soccer referees","authors":"Alfonso Castillo-Rodríguez, Wanesa Onetti-Onetti, Filipe Manuel Clemente, Francisco Tomás González-Fernández","doi":"10.1177/17543371231208401","DOIUrl":"https://doi.org/10.1177/17543371231208401","url":null,"abstract":"The aim of this study was to define and classify the different physical and physiological performance metrics on national and non-national soccer referees (SRs) through GPS technology. Sixty SRs (age: 28.9 ± 4.9 years; weight: 70.2 ± 8.0 kg; height: 175.7 ± 5.5 cm) were tested using the 18 Hz global positioning system (GPS) (WimuPro, Realtrack, Almería, Spain). An exploratory factor analysis was performed using principal component analysis (PCA) on performance indicators with orthogonal rotation (VariMax). Thirteen metrics (total distance, distance covered at different speeds, maximum heart rate, and heart rate recorded in different zones) were integrated in three principal components, activation (PCA1), recovery (PCA2), and high intensity (PCA3). They represented 86% and 89% of total explained variance of the competition performance in national and non-national SRs, respectively. Distance covered at very high speed and heart rate between 80% and 89.9% of the maximum integrated the high-intensity principal component and were higher in non-national SRs. The main finding of this study was that it defined for the first time in the scientific literature the main components that discriminate physical performance between national and non-national referees, where high intensity metrics have greater weight in non-national referees. In addition, GPS technology together with PCA analysis were presented as useful methods to discriminate the most representative physical and physiological performance metrics in sports competition in SRs.","PeriodicalId":20674,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology","volume":"3 s1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135773547","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 : 2023-09-30DOI: 10.1177/17543371231203440
Rohit K Thapa, Bhargav Sarmah, Tanvi Singh, Gaurav S Kushwah, Zeki Akyildiz, Rodrigo Ramirez-Campillo
This study aimed to assess the test-retest reliability of untested single- and dual-beam timing gates and compare them with previously validated video-based applications to measure linear and change of direction sprint (CODS) times. Twenty-three participants were concurrently assessed for 30 m linear sprint and CODS time using single- and dual-beam timing gates and the MySprint and COD Timer applications. Interclass correlation coefficient (ICC), Pearson correlation, independent t-test and Bland-Altman plots were used for comparison between instruments. ICC, Cronbach’s alpha and coefficient of variation (CV) analyses were used to assess the test-retest reliability. Excellent ICC was noted for test-retest reliability (0.982–0.984 [sprint], 0.940–0.942 [CODS]), with a high Cronbach’s alpha (all 0.997 [sprints], 0.988–0.989 [CODS]) and acceptable CV (1.296–1.946%) for all the timing systems. Similarly, excellent ICC (0.989–0.994 [sprint], 0.998–0.999 [CODS]) and very high correlation ( r = 0.990–0.994 [sprints] and r = 0.998–1.000 [CODS]) were reported between the single- and dual-beam timing gates, and the MySprint and COD Timer applications, with non-significant differences between the measurements ( p = 0.754–0.960). However, the Bland-Altman plots represented that values measured with the three instruments were inconsistent with most values away from the mean of the difference between instruments. In conclusion, both photocell timing systems are reliable instruments for measuring linear sprint time and CODS time. However, the timing systems should not be used interchangeably to interpret findings. Furthermore, it is suggested that similar timing systems with an identical setup should be used for the measurement of timings for interpretations.
{"title":"Test-retest reliability and comparison of single- and dual-beam photocell timing system with video-based applications to measure linear and change of direction sprint times","authors":"Rohit K Thapa, Bhargav Sarmah, Tanvi Singh, Gaurav S Kushwah, Zeki Akyildiz, Rodrigo Ramirez-Campillo","doi":"10.1177/17543371231203440","DOIUrl":"https://doi.org/10.1177/17543371231203440","url":null,"abstract":"This study aimed to assess the test-retest reliability of untested single- and dual-beam timing gates and compare them with previously validated video-based applications to measure linear and change of direction sprint (CODS) times. Twenty-three participants were concurrently assessed for 30 m linear sprint and CODS time using single- and dual-beam timing gates and the MySprint and COD Timer applications. Interclass correlation coefficient (ICC), Pearson correlation, independent t-test and Bland-Altman plots were used for comparison between instruments. ICC, Cronbach’s alpha and coefficient of variation (CV) analyses were used to assess the test-retest reliability. Excellent ICC was noted for test-retest reliability (0.982–0.984 [sprint], 0.940–0.942 [CODS]), with a high Cronbach’s alpha (all 0.997 [sprints], 0.988–0.989 [CODS]) and acceptable CV (1.296–1.946%) for all the timing systems. Similarly, excellent ICC (0.989–0.994 [sprint], 0.998–0.999 [CODS]) and very high correlation ( r = 0.990–0.994 [sprints] and r = 0.998–1.000 [CODS]) were reported between the single- and dual-beam timing gates, and the MySprint and COD Timer applications, with non-significant differences between the measurements ( p = 0.754–0.960). However, the Bland-Altman plots represented that values measured with the three instruments were inconsistent with most values away from the mean of the difference between instruments. In conclusion, both photocell timing systems are reliable instruments for measuring linear sprint time and CODS time. However, the timing systems should not be used interchangeably to interpret findings. Furthermore, it is suggested that similar timing systems with an identical setup should be used for the measurement of timings for interpretations.","PeriodicalId":20674,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136341729","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 : 2023-09-27DOI: 10.1177/17543371231200295
Santiago A Ruiz-Alias, Alberto A Ñancupil-Andrade, Alejandro Pérez-Castilla, Felipe García-Pinillos
This study aims to determine the validity of the critical power (CP) and the work capacity over CP (W′) obtained from different two-time trial combinations with respect a five-point model. In a 3-week training period, 15 athletes (age: 23 ± 5 years; height: 166 ± 6 cm; body mass: 58 ± 8 kg; 5 km season-best: 15:29 ± 00:53 mm:ss) performed five time-trials (i.e. 3, 4, 5, 10, 20 min) on a 400 m track, from which the mean power outputs were obtained through the Stryd Power Meter. An acceptable level of agreement was considered if the following criteria were met: low bias and standard error of the estimate (SEE) (<14 W [values corresponding to the ±5% of the mean CP]; W′: <2.0 kJ [values corresponding to the ±10% of the mean W′]), R 2 > 0.90, and ICC > 0.81. The CP presented an acceptable SEE for CP work (1.3 ± 0.5%) and CP 1/time (2.7 ± 1.1%) when using the five time-trials. For both CP models, the 3–10 min was the shortest valid combination, whereas the 3–20, 4–20, and 5–20 min showed the greatest level of agreement. The W′ presented a high SEE for CP work (14.1 ± 5.2%) and CP 1/time (13.8 ± 6.2%) when using the five time-trials, therefore, none of the two time-trials combinations were considered. The CP parameter can be accurately estimated from different two time-trial combinations, whereas none reached an acceptable level of accuracy for the determination of W′.
{"title":"Determining critical power and <i>W′</i> in running: Accuracy of different two-point models using the power metric","authors":"Santiago A Ruiz-Alias, Alberto A Ñancupil-Andrade, Alejandro Pérez-Castilla, Felipe García-Pinillos","doi":"10.1177/17543371231200295","DOIUrl":"https://doi.org/10.1177/17543371231200295","url":null,"abstract":"This study aims to determine the validity of the critical power (CP) and the work capacity over CP (W′) obtained from different two-time trial combinations with respect a five-point model. In a 3-week training period, 15 athletes (age: 23 ± 5 years; height: 166 ± 6 cm; body mass: 58 ± 8 kg; 5 km season-best: 15:29 ± 00:53 mm:ss) performed five time-trials (i.e. 3, 4, 5, 10, 20 min) on a 400 m track, from which the mean power outputs were obtained through the Stryd Power Meter. An acceptable level of agreement was considered if the following criteria were met: low bias and standard error of the estimate (SEE) (<14 W [values corresponding to the ±5% of the mean CP]; W′: <2.0 kJ [values corresponding to the ±10% of the mean W′]), R 2 > 0.90, and ICC > 0.81. The CP presented an acceptable SEE for CP work (1.3 ± 0.5%) and CP 1/time (2.7 ± 1.1%) when using the five time-trials. For both CP models, the 3–10 min was the shortest valid combination, whereas the 3–20, 4–20, and 5–20 min showed the greatest level of agreement. The W′ presented a high SEE for CP work (14.1 ± 5.2%) and CP 1/time (13.8 ± 6.2%) when using the five time-trials, therefore, none of the two time-trials combinations were considered. The CP parameter can be accurately estimated from different two time-trial combinations, whereas none reached an acceptable level of accuracy for the determination of W′.","PeriodicalId":20674,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135537770","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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