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Journal of New Studies in Sport Management     Open Access   (Followers: 9)

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Proceedings of the Institution of Mechanical Engineers Part P: Journal of Sports Engineering and Technology
Number of Followers: 4  
 
  Hybrid Journal Hybrid journal (It can contain Open Access articles)
ISSN (Print) 1754-3371 - ISSN (Online) 1754-338X
Published by Sage Publications Homepage  [1176 journals]
  • A comparative evaluation of Elo ratings- and machine learning-based
           methods for tennis match result prediction

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      Authors: Rory Bunker, Calvin Yeung, Teo Susnjak, Chester Espie, Keisuke Fujii
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology, Ahead of Print.
      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.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology
      PubDate: 2023-11-11T07:17:23Z
      DOI: 10.1177/17543371231212235
       
  • SALUTRACK: A smartphone application to evaluate and monitor injuries and
           health problems in athletes from the Balearic Islands

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      Authors: Andreu Sastre-Munar, Natalia Romero-Franco
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology, Ahead of Print.
      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.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology
      PubDate: 2023-11-07T01:15:07Z
      DOI: 10.1177/17543371231208847
       
  • Principal components approach of physiological and physical metrics
           collected through GPS technology in soccer referees

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      Authors: Alfonso Castillo-Rodríguez, Wanesa Onetti-Onetti, Filipe Manuel Clemente, Francisco Tomás González-Fernández
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology, Ahead of Print.
      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.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology
      PubDate: 2023-11-04T11:13:50Z
      DOI: 10.1177/17543371231208401
       
  • Tribological devices in cycling: A review

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      Authors: Rémi Aubert, Xavier Roizard, Frédéric Grappe, Fabrice Lallemand
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology, Ahead of Print.
      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 (Ft). Ft 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 Ft, 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.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology
      PubDate: 2023-11-04T11:09:03Z
      DOI: 10.1177/17543371231202562
       
  • 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

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      Authors: Rohit K Thapa, Bhargav Sarmah, Tanvi Singh, Gaurav S Kushwah, Zeki Akyildiz, Rodrigo Ramirez-Campillo
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology, Ahead of Print.
      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.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology
      PubDate: 2023-09-30T08:58:34Z
      DOI: 10.1177/17543371231203440
       
  • Determining critical power and W′ in running: Accuracy of different
           two-point models using the power metric

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      Authors: Santiago A Ruiz-Alias, Alberto A Ñancupil-Andrade, Alejandro Pérez-Castilla, Felipe García-Pinillos
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology, Ahead of Print.
      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) ( 0.81. The CP presented an acceptable SEE for CPwork (1.3 ± 0.5%) and CP1/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 CPwork (14.1 ± 5.2%) and CP1/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′.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology
      PubDate: 2023-09-27T10:46:03Z
      DOI: 10.1177/17543371231200295
       
  • Technology and digital transformation for the structural reform of the
           sports industry: Building the roadmap

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      Authors: Ana María Magaz-González, Marta García-Tascón, César Sahelices-Pinto, Ana María Gallardo, Juan Carlos Guevara Pérez
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology, Ahead of Print.
      The COVID-19 pandemic in 2020, has accelerated technological immersion into society, economy and public administrations. The sports organisations are no strangers to this digitisation and must carry out their own digital transformation. However, investment in digital technology must be preceded by a diagnosis of the technological needs of each sports entity. Said mapping will help organisations know the most appropriate technological tools for their core businesses so they can properly design their digital transformation strategies. The objectives of this study were to design and create a tool to understand the digital structure of Spanish sports. The result has been the configuration of an instrument that includes the description of different technologies and different digital competencies specific to the sports industry, and which allows individuals to know the use, importance, perceived difficulty of use and economic accessibility of available technologies, as well as the degree of developed competency in the different sports organisations. It is concluded that the creation and application of a consultation instrument on digitalisation is the first and necessary step to carry out relevant, in-depth, valid and replicable research, which allows information to be gathered on the digitalisation needs of sports organisations to design their digital transformation roadmap and that the aids for digital transformation is distributed efficiently.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology
      PubDate: 2023-09-26T09:31:18Z
      DOI: 10.1177/17543371231197323
       
  • The use of mobile solutions for biomechanical assessment in combat sports:
           A narrative review

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      Authors: Jader Sant’ Ana, Rafael Lima Kons, Daniele Detanico, Fernando Diefenthaeler
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology, Ahead of Print.
      New technologies have amplified the possibilities for processing and incorporating data and scientific methods in algorithms through the integration of the use of mobile technology and a wide range of wearables that allow acquisition metrics in real-time. These technologies arise as a possible alternative to supply market demand and to present practical solutions to problems that coaches and athletes face in their daily routines. Concerning biomechanical assessment in combat sports (i.e. reaction time, velocity, and force), the literature is scarce regarding studies that carried out surveys of new assessments and monitoring technologies, with solutions for coaches and athletes. Therefore, the current study aimed to investigate, through a literature review, mobile technologies available on the market for biomechanical analyses in combat sports modalities. Significant growth has been observed in the number of studies involving mobile technologies with practical tools for biomechanical assessment in combat sports athletes. However, only seven technological proposals presented scientific reliability studies, and six assessed validity, showing the necessity of more original articles to investigate scientific validation. As a suggestion, a flowchart is presented with operational guidelines for the research and development of new technologies for biomechanical assessment and monitoring in combat sports in real-time.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology
      PubDate: 2023-09-26T09:28:28Z
      DOI: 10.1177/17543371231199810
       
  • Using machine learning to determine the positions of professional soccer
           players in terms of biomechanical variables

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      Authors: Fatma Hilal Yagin, Uday CH Hasan, Filipe Manuel Clemente, Ozgur Eken, Georgian Badicu, Mehmet Gulu
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology, Ahead of Print.
      This study aimed to predict professional soccer players’ positions with machine learning according to certain locomotor demands. Data from 20 male professional soccer players (five defenders, eight midfielders, and seven attackers) from the same team were tracked daily with a global navigation satellite system. A total of 1910 individual training sessions were recorded. The 10-fold cross-validation method was used. Soccer player positions were predicted using predictive models created with random forest (RF), gradient boosting tree, bagging classification, and regression trees algorithms, and the results were evaluated with comprehensive performance measures. Ratios and an importance plot were used to analyze the importance of the variables according to their contributions to the estimation. The findings show that the RF model achieved 100% accuracy, which means that RF can predict all player positions (100%). Running distance (26.5%), total distance (17.2%), and player load (15.8%) were the three variables that contributed the most to the estimation of the RF model and were the most important factor in distinguishing player positions. Consequently, our proposed machine learning approach (RF model) can reduce false alarms and player mispositioning.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology
      PubDate: 2023-09-15T10:36:33Z
      DOI: 10.1177/17543371231199814
       
  • Horse gait analysis using wearable inertial sensors and machine learning

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      Authors: Manju Rana, Vikas Mittal
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology, Ahead of Print.
      Equestrian sports require horses to possess physical and mental attributes such as agility, strength, balance, and gymnastic skills. Performance analysis is critical in evaluating a horse’s performance, which involves assessing athleticism, gait quality, jumping ability, and general health. Assessing the kinematics of horses is crucial for selecting, training, and managing sports horses. Understanding a horse’s gait pattern and detecting Ground Reaction Forces (GRF) help diagnose lameness in the horse. Traditional gait analysis methods are performed visually, which can be biased due to subjectivity and human error. Optical motion capture (OMC) technology for equine gait analysis is expensive and ideal for indoor use. Wearable inertial measurement units (IMUs) offer a cost-effective alternative for analyzing kinematic parameters. This study has devised novel wearable sensor devices for horses and riders to measure forces acting on the legs and body of the horse and the orientation of their legs during field performance. Ground Reaction Forces (GRF) were measured using 100g accelerometer data from each leg to assist owners and riders in analyzing the magnitude of forces and detecting any anomalies. Machine-learning models were developed to classify horse movements, such as jumps, stands, gallops, and trots, using features extracted from the data collected by wearable sensor devices. These models were compared to identify the most effective model for accurately classifying horse movements. This approach provides a valuable tool for recognizing patterns and trends in the data, enabling owners and riders to make informed decisions about training and management strategies.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology
      PubDate: 2023-09-15T10:34:00Z
      DOI: 10.1177/17543371231196814
       
  • A Random Forest clustering to explore the influence of physical fitness
           level of youth basketball players on match-related physical performance

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      Authors: Diego Marqués-Jiménez, Javier Raya-González, Silvia Sánchez-Díaz, Daniel Castillo
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology, Ahead of Print.
      This study aimed to analyse the influence of different physical fitness levels of youth basketball players on match-related physical performance, using Random Forest clustering to distinguish between high-fitness level players and low-fitness level players. Twenty male youth basketball players completed the following physical performance tests in two separate sessions: bilateral and unilateral countermovement jumps, bilateral and unilateral horizontal jumps, single leg lateral jumps, the 20 m linear straight sprint test, the 505 test and a repeated sprint ability test. 1 week after the second testing day, players completed a simulated match while external loads were monitored using an ultra-wide band-based Local Positioning System. A Random Forest clustering was used to create two different clusters composed of players with similar physical fitness attributes (high- and low-fitness level players). Results indicate that the Random Forest clustering adequately discriminated among the players in different groups according to their physical fitness attributes. High-fitness level players covered more distance per min in all intensity thresholds and reached higher maximal speed and acceleration intensity during the simulated matches (p 
      Citation: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology
      PubDate: 2023-09-15T04:41:22Z
      DOI: 10.1177/17543371231200056
       
  • The use of technology in the assessment and monitorization of a season in
           a professional padel player: A case study

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      Authors: Angel Carnero-Diaz, Javier Pecci, Gonzalo Reverte-Pagola, Marzo Edir Da Silva-Grigoletto
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology, Ahead of Print.
      Training process in elite padel players is influenced by travels and competitions density. The irregularity in the workloads, as well as demands of the season, could affect the musculoskeletal structures. Strength training has a protective role against the injury incidence, but the competitive context does not always allow adequate periodization of training and thus achieve adaptations. The aim of this study is to analyze, using technological tools, if improvements in player’s fitness are accompanied by improvements in sport performance through a case study. An elite padel player was analyzed during the 2021 season. Physical fitness was evaluated using different technological tools. Athlete monitoring was carried out using self-reported forms and sport performance was assessed through the results obtained in the World Padel Tour ranking at the end of the season. During the training process, multidimensional training was carried out in order to achieve the maximum availability of specific loads through coadjuvant training. Results of the assessment show slight improvements in all fitness tests. Assessment of sport performance reports an increased number of victories and a better position in the professional ranking. Musculoskeletal improvements helped the athlete’s workload tolerance, allowing overall improvement in padel performance. The training approach from this study has shown to be effective in maintaining or even improving force-producing capacity in lower and upper limbs, force-velocity relationship, agility and sport performance, despite the high competitive density. This work provides coaches with a practical approach to assess, monitor and design a competitive season for an elite padel player.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology
      PubDate: 2023-09-15T04:38:11Z
      DOI: 10.1177/17543371231199812
       
  • The effects of a 12-week yoga program on the CoP of military pilots before
           and after a flight emergency simulation using Biosignals Plux force
           platform

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      Authors: Sara Santos, José Alberto Parraca, Joana Alegrete, Carolina Alexandra Cabo, Filipe Melo, Orlando Fernandes
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology, Ahead of Print.
      This study examined the effects of Ashtanga Vinyasa Yoga Supta on Center of Pressure (CoP) displacement in healthy student pilots, using the Biosignals Plux force platform, under the premise that yoga would lead to improvements in postural control responses. CoP response was analyzed by the Plux (Portugal) one-dimensional force platform. A total of 18 military pilots participated in this study. The pilots were in their Portuguese Air Force Academy course “Masters in Military Aeronautics: Aviator Pilot Specialist,” also called Tirocinium. Participants were randomly assigned to yoga classes (intervention group) or a waiting list (control group) and completed a flight emergency protocol in a flight simulator. CoP displacement was collected before and after all these maneuvers had been completed and both measures occurred before (baseline values) and after a 12-week yoga program. Although the differences observed between groups are not significant, after calculating the effect size, we can theorize that the intervention group maintains CoP displacement before and after flight and the control group has a higher CoP displacement after flight simulation. CoP information collected through noninvasive portable devices such as the Biosignals Plux force platform can relay important information quickly and easily. Knowing under what circumstances pilots are affected can then lead to development or enhancement of training strategies to improve those psychophysiological responses. In this study the effects, while not significant, are present, so it may be necessary to add more weeks of training to make the yoga program effective.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology
      PubDate: 2023-09-08T12:24:40Z
      DOI: 10.1177/17543371231196340
       
  • Novel tactical insights from Men’s 2022 FIFA World Cup: Which
           performance indicators explain the teams’ goal difference'

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      Authors: Gibson Moreira Praça, Leandro Henrique Albuquerque Brandão, Cristóvão de Oliveira Abreu, Pedro Henrique de Almeida Oliveira, André Gustavo Pereira de Andrade
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology, Ahead of Print.
      This study examined positional and event-based tactical variables during the Men’s 2022 FIFA World Cup to detect differences between winning and losing teams and to verify which variables would better predict the goal difference between the teams. All 64 matches played during the competition were initially considered. Due to the purpose of the current article, draw matches were excluded from the sample. The data were compared between the match statuses using a MANOVA. A stepwise multiple linear regression was used to detect which variables predict the outcome of the matches. Results indicated differences between winning and losing in Line Breaks per Pass (p = 0.011), Defensive Line Break per Pass (p = 0.004), Final Third Phase Height (p = 0.023), and Width (p 
      Citation: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology
      PubDate: 2023-09-08T12:05:16Z
      DOI: 10.1177/17543371231194291
       
  • Acute:chronic workload ratio and training monotony variations over the
           season in professional soccer: A systematic review

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      Authors: Markel Rico-González, Francisco Tomás González Fernández, Rafael Oliveira, Filipe Manuel Clemente
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology, Ahead of Print.
      Acute: chronic workload ratio (ACWR) and training monotony have been criticized as injury risk predictors. Therefore, the use of intensity measures should be oriented to understand the variations of intensity across the season. The aim of this systematic review is to summarize the main evidence about the ACWR and training monotony variations over the season in professional soccer players. The search was made in PubMed, SPORTDiscus, and FECYT according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. From the 225 studies initially identified, 27 were fully reviewed, and their outcome measures were extracted and analyzed. Existing literature revealed a variety of designs, ACWR and training monotony ranges, variables assessed and durations of the studies. Overall, the range values for ACWR were 0.4–3.39 AU, while those focused on monotony were 0.49–5.7 AU. Regarding ACWR, the ratios located around 0.85–1.25 could predict lower risk values and ratios around ≥1.50 could predict higher risk values. On the contrary, with respect to training monotony, the ratios are approximately between 0.5 and 2.00 (low values in the preseason and low competition weeks and high values when soccer players are in highly scheduled competition weeks). Nevertheless, ACWR and training monotony methods should be addressed and considered based on their real value before using this indicator to reduce injury risk. In fact, the data did not conclusively define injured and non-injured players. For this reason, utilizing standardized approaches will allow for more precise conclusions about professional soccer players.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology
      PubDate: 2023-09-08T11:59:47Z
      DOI: 10.1177/17543371231194283
       
  • Non-exercise-based racing time prediction of cross-country skiers using
           machine learning methods combined with Relief-F feature selection

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      Authors: F Abut, MF Akay, S Daneshvar, A Özcan, D Heil
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology, Ahead of Print.
      This study proposes new non-exercise models for estimating the racing time of cross-country skiers. Machine learning methods employed to build the prediction models include General Regression Neural Network (GRNN), Support Vector Machine (SVM), Multilayer Feed-Forward Artificial Neural Network (MFANN), and Radial Basis Function Neural Network (RBFNN), whereas the Relief-F algorithm combined with a ranker search has been utilized as the feature selector. The self-created data set contains samples collected from 370 cross-country skiers with inhomogeneous capabilities. Each sample in the data set contains physiological variables such as sex, age, height, weight, and body mass index (BMI) combined with an immersive set of survey data. The outcomes suggest that generally, the GRNN-based models exhibit the best prediction performance and can be used as a feasible tool for the prediction of the racing time of cross-country skiers with tolerable root mean square errors (RMSEs). It is seen that inclusion of age and assigned starting wave of cross-country skiers in models leads to much lower RMSEs, suggesting that the racing time of cross-country skiers is highly correlated to these two predictor variables. When compared with the exercise-based models, the proposed non-exercise-based models produce consistently comparable prediction performance for all evaluated machine learning methods. The non-exercise-based models have the relevant benefit of practical feasibility, as the models do not require the skiers to complete physical exercises and are also applicable to a wide range of cross-country skiers.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology
      PubDate: 2023-09-02T07:13:12Z
      DOI: 10.1177/17543371231194011
       
  • Investigating the influence of head kinematics on head injury metrics and
           factors to consider for football helmet design

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      Authors: Lillian S Chatham, Trevor S Young, Richard M Wojcik, Lyssa A Bell, Amir H Torbati, Robert Dana Carpenter, Peter E Jenkins, Sourav K Poddar, Christopher M Yakacki
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology, Ahead of Print.
      There is a need to understand the relationship between head kinematics, impact severity metrics, and overall helmet performance as sports-related concussions continue to be prevalent. This study evaluates these relationships, emphasizing newly developed severity metrics that consider both translational and rotational contributions. Impact tests were performed following the NFL testing protocol on four prominent football helmets. The resulting data was used to determine Head Acceleration Response Metric (HARM), Diffuse Axonal Multi-Axis General Evaluation (DAMAGE), and Head Injury Criterion (HIC). HARM scores, a combination of HIC and DAMAGE, were ultimately used to solve for a Helmet Performance Score. When analyzing all impacts, DAMAGE showed a stronger correlation to HARM than HIC (R2 = 0.76 vs R2 = 0.57); however, the strongest correlation existed between peak resultant angular velocity (PRAV) and HARM (R2 = 0.87). When examining impacts at only the side, side upper (SU), and oblique front (OF) locations grouped together, HIC demonstrated the strongest correlation to HARM in the study (R2 = 0.96). PRAV was the best predictor for HARM over peak resultant linear acceleration (PRLA) and peak resultant angular acceleration for four of the six impact locations (C, D, FMCO, and FMS) when analyzing the sites individually. The remaining locations (SU and OF) best predicted HARM using PRLA. These results are presented and discussed to aid in the research, design, and development of football helmets.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology
      PubDate: 2023-08-31T06:46:09Z
      DOI: 10.1177/17543371231194669
       
  • Do contextual factors influence running and accelerometry GPS based
           variables in professional women soccer players' A case study about the
           effect of match location and result

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      Authors: Rafael Oliveira, Halil İbrahim Ceylan, Renato Fernandes, Ryland Morgans, Hadi Nobari, Matilde Nalha, João Paulo Brito
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology, Ahead of Print.
      The aims of this study were to compare external match load between home and away matches as well as the result of the match (win, draw, and loss). The secondary aim was to quantify external training load that preceded the next match taking into account both match location and result. Ten elite women soccer players participated in the study (age 24.6 ± 2.3 years). Seven home and seven away matches in which four wins, three draws, and seven losses occurred. The following global positioning system (GPS) metrics were analyzed: duration, total distance, high-speed running distance (HSR, ≥15 km h−1), number of accelerations (ACC) and decelerations (DEC), average speed, and player load. There were no significant differences between match results and match locations. Regarding comparisons of training data preceding different match results, only duration and player load did not differ while HSR, number of ACC and DEC showed to be higher when the next match was a loss (p 
      Citation: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology
      PubDate: 2023-08-16T11:04:09Z
      DOI: 10.1177/17543371231194004
       
  • Transportation sand leakage and turf performance of sand-based removable
           modular turf as affected by the combined action of coir fiber and
           polyacrylamide

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      Authors: Chen Yufeng, Zhang Peng, Han Liebao, Qian Yongqiang, Song Guilong, Yang Xiaohui
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology, Ahead of Print.
      Removable modular turf with a sand-based rootzone is a solution for high-end stadiums which can organize various events on the turf. However, the low stability of sand leads to serious sand leakage during the transportation of modular turf, which reduces the evenness and safety of the turf. Previous studies have shown that adding coir fibers (CF) and polyacrylamide (PAM) will improve soil stability. In this study, we evaluated the combined effects of CF and different amounts of PAM on soil properties, turfgrass growth, shear strength, and sand leakage during simulated transport vibrations in a sand-based modular turf planted with tall fescue (Festuca elata Keng ex E. Alexeev). Each treatment comprised a mixture of 0.4% (weight material/weight soil) CF and six concentrations of PAM (0%, 0.025%, 0.050%, 0.075%, 0.100%, 0.125%, w/w) in the sand-based rootzone, with no addition of CF or PAM as the control. The results show that, in the sand-based rootzone, CF could improve tall fescue growth, shear strength, and resistance to sand leakage owing to transport vibration due to the physical properties of the coir fiber. However, the combined effect of CF and 0.100% PAM was better for tall fescue growth, shear strength, and resistance to sand leakage. However, owing to the lubricating effect of PAM, adding a low (≤0.025%) or a high rate (≥0.125%) amount of PAM would reduce the effect of CF and PAM. Therefore, the combined effect of CF + 0.100% PAM in this study had the best effect on the turf module and can be used as an application scheme for the removable modular turf.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology
      PubDate: 2023-08-16T11:01:04Z
      DOI: 10.1177/17543371231193268
       
  • Consequences of field obstacles on tactical, conditional, and emotional
           dimensions in young female soccer players during small-sided games

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      Authors: Asier Los Arcos, Asier Gonzalez-Artetxe, Uxue Bayer-Perez, Hugo Folgado
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology, Ahead of Print.
      This study aims to compare tactical, conditional, and emotional responses of young female soccer players with two small-sided games (SSG) conditions – with and without field obstacles. Twelve Spanish under-12 female soccer players (age: 12.5 ± 0.7 years) played two different 6-a-side SSGs (i.e. 5 vs 5 plus goalkeepers): one with field obstacles (SSGobstacles) and the other without these (SSGfree). Positional data were gathered using a GPS to measure tactical (distance between players, stretch-index [SI], spatial exploration index [SEI] and their normalized approximate entropy measures [ApEn norm], and longitudinal and lateral synchronizations) and conditional performances (total and walking, jogging, running, and high-speed running distances). Participants assessed the intensity of their emotional experience using the BECS scale of perceived enjoyment and competence. SSGobstacles reduced the SEI values (p = 0.038, Cohen’s d = −0.40 [−0.77; −0.02]), impaired lateral synchronization (p 
      Citation: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology
      PubDate: 2023-08-09T11:59:56Z
      DOI: 10.1177/17543371231191845
       
  • Aerodynamic drag study of speed skaters using CFD simulations

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      Authors: Yuju Wei, Yanqing Wang, You Nie, Ding Weng, Lei Chen, Yuan Ma, Zuobo Pang, Jiadao Wang
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology, Ahead of Print.
      The aerodynamic drag of speed skaters was analyzed numerically at different posture angles of head, back and arm as well as team formation. Computational Fluid Dynamics (CFD) method was used to investigate the optimized posture of the skater and the drag law of the team formation. Detached Eddy Simulation (DES) was used as the numerical technique. CFD results showed that the drag area of the skater increased with the increasing angle of the head, back, and arms due to the increased high-pressure areas on the windward side and the increased low-pressure areas on the leeward side of the skater. CFD results also showed that all three skaters had lower drag area in the team pursuit competition compared with an isolated skater. The drag area of the latter two skaters was significantly smaller than that of the first skater, and the drag area of the foremost skater increased sharply when the axial spacing was more than 0.6 m. The drag area for all three skaters increased as the lateral offset increased. Moreover, the research in this paper presented an important reference for the drag reducing optimization of speed suits and helmets, and the method could be expanded to other sports.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology
      PubDate: 2023-08-05T10:21:33Z
      DOI: 10.1177/17543371231188558
       
  • Development of prototypes in sport: A systematic review

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      Authors: Júlio César Gomes da Silva, Kalinne Fernandes Silva, Carlos Eduardo Coelho Freire Batista, Gabriel Teixeira Patrício, Gilmário Ricarte Batista
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology, Ahead of Print.
      This study systematically reviewed the available scientific evidence pertaining to the different types of prototypes available, discussed their current use, and present and future applications in sports science. The electronic databases National Library of Medicine (PubMed), Web of Science™ and Scopus were searched from January 2016 to September 2021. Of the 750 articles identified, 714 articles were excluded based on title and abstract and/or for duplicates. Moreover, of the 36 articles selected, 11 articles (30.5%) were related to the development of prototypes for carrying out tactical-technical or physical performance analyzes of athletes in different sports, 22 articles (61.1%) were related to the creation of “equipment or clothing” prototypes used in sports activities and three articles (8.3%) were related to the creation of prototypes that aim to improve the technical performance of athletes. It was concluded that the development of prototypes in sport had a significant impact on the monitoring of athletes in the field of sport sciences. The prototypes provide coaches and technical professionals with the monitoring of physiological, tactical-technical, and physical parameters in real time during training and sports competitions. These parameters can be used for recognition of movement patterns and prevention of potential injuries, such as concussion and fatigue.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology
      PubDate: 2023-08-02T06:19:25Z
      DOI: 10.1177/17543371231189920
       
  • Validity of a wearable device for measuring vertical displacement and jump
           count in young artistic roller skating athletes

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      Authors: André Rebelo, Diogo Santos Teixeira, João Valente-dos-Santos, Ricardo Franco Lima
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology, Ahead of Print.
      The present study aimed to investigate the validity of a small inertial sensor (Vert IMU) for measuring vertical displacement and jump count in young female artistic roller skating athletes. Two separate investigations were completed. In the first, 12 subjects were asked to perform 24 jumps each, and jump heights were simultaneously assessed by the Optojump photocells (criterion instrument) and by the Vert IMU and compared to evaluate concurrent validity of this latter system. The second investigation evaluated the capacity of the Vert to correctly identify jumps during training sessions. The correlation between the Vert device and the Optojump was strong for all jump types (r = 0.84–0.95), except for the double Salchow which had a moderate correlation (r = 0.55). All 288 jumps in Investigation One had a significant (p 
      Citation: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology
      PubDate: 2023-07-21T09:56:39Z
      DOI: 10.1177/17543371231188400
       
  • Experimental characterization of artificial turf infill mixtures and
           implementation in smoothed particle hydrodynamics numerical model

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      Authors: Brock Watson, Michael C Bustamante, Aleksander Rycman, Matheus A Correia, Duane S Cronin
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology, Ahead of Print.
      Quantifying the response of infill used to construct contemporary artificial turf is critical to the development of computational models and providing insights to reduce sports injury associated with artificial turf. In the current study, confined compression and direct shear tests were performed on typical infill materials (sand, SBR and two mixtures (33%: 67%) by-weight). The experimental tests exhibited a progression from high strength and stiffness (sand) to low strength and stiffness (SBR) with the mixtures having intermediate values. Increasing particle size, particularly sand, tended to increase the resistance of the infill to deformation. The experimental results were implemented into a soil constitutive material model and the experimental tests were simulated using a smoothed particle hydrodynamics (SPH) method to verify the implementation in a commercial explicit finite element solver. The SPH method successfully captured the initial loading up to yield, material flow and post-yield behavior, enabling large-scale particle flow that will be necessary to simulate artificial turf. The simulation results predicted the test force-displacement response well for SBR and mixture infills. The proposed methodology demonstrated the ability to measure properties of contemporary artificial turf infills in both compression and shear for pure sand, pure SBR and mixtures of the two, and use these properties to accurately represent the infill in a computational environment. The resulting model can be extended to large-scale turf models, to investigate athlete performance and injury risk when interacting with artificial turf.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology
      PubDate: 2023-07-13T11:23:11Z
      DOI: 10.1177/17543371231186861
       
  • A technology-based experience to improve badminton skills: A
           challenge-based learning application

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      Authors: Alba González-Peño, Luis Simón-Chico, Leonor Prieto, Evelia Franco
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology, Ahead of Print.
      In recent years, it has become evident that technologies are part of daily life and can be useful and helpful to improve teaching and learning processes in education. Specifically, this evidence has highlighted the positive effect of technologies on improving motor skills. This study presents a technology-based learning (TBL) proposal and analyses how the implementation of such a proposal in physical education (PE) might affect students’ academic performance (theoretical knowledge and practical competence). A quasi-experimental study was carried out with experimental and control groups. A total of 84 participants (35 males and 49 females) between 13 and 15 years of age (Mage = 13.35, SD = 0.62) took part in the experience over a period of 6 weeks (ncontrol = 49; nexperimental = 35). The teacher assessed students’ practical competence level in both the experimental and control groups to verify homogeneity. Theoretical knowledge and badminton-specific motor skill tests were performed in both groups after the intervention. Analysis showed that, after the intervention, students in the TBL group significantly increased their levels of badminton-specific motor skills (Mcontol = 7.01 vs Mexperimental = 7.73) compared with students in the control group. No significant changes were observed for theoretical knowledge. The findings of this study highlight that the integration of technologies in PE might be a valid and effective methodological approach for PE students to achieve adaptive learning outcomes and improve their academic performance.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology
      PubDate: 2023-07-05T09:39:57Z
      DOI: 10.1177/17543371231185913
       
  • Impact of a cue with a billiard ball

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      Authors: Rod Cross
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology, Ahead of Print.
      Experimental results are presented to show how the speed and spin of a billiard ball vary as the impact point of the cue is varied above and below the center of the ball. The results are compared with a simple impact model to estimate how the normal and tangential impact forces vary with impact location.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology
      PubDate: 2023-06-29T08:22:49Z
      DOI: 10.1177/17543371231184011
       
  • Three-defender versus two-defender systems in football: A comparison of
           offensive play

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      Authors: Fernando M Otero-Saborido, Sergio Torreblanca-Martinez, Victor Torreblanca-Martinez, Fabio Nevado-Garrosa, Manuel Nuñez-Campos, Jose A González-Jurado
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology, Ahead of Print.
      Scientific research on tactical formations in football is scarce and the studies that do exist focus on aspects linked to physical conditioning. Therefore, the objective of this work was to analyse offensive play differences between three-centre-back (3CB) and two-centre-back (2CB) formations. A total of 72 matches played by eight LaLiga teams (Spain) during the 2018–19 season were analysed. Four teams used a 3CB system and four teams a 2CB system. Data were obtained from the Opta sports company, and the reports were generated using Mediacoach. Three groups of variables were analysed (passes, possession and finishing). The results showed that both the number of team passes (‘passes received’, ‘passes attempted’) and their effectiveness (‘number’ and % of ‘completed’ passes) were significantly greater (p 
      Citation: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology
      PubDate: 2023-06-02T10:08:42Z
      DOI: 10.1177/17543371231178043
       
  • Application of technology for the analysis of Small-Sided Games in
           football. From complexity to chaos in training design: Reference to number
           of players, playing space, orientation, time distribution, directionality
           with goalkeepers, and feedback

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      Authors: Iván Asín-Izquierdo, Luis Gutiérrez-García, Carlos Galiano
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology, Ahead of Print.
      Small-sided games (SSGs) are frequently used in football training programs and their design has been analyzed in scientific literature. The aim of this study was to analyze differences in the mechanical and physiological demands of football SSGs with various configurations over an effective time of 6 min through the application of GPS/GNSS technology, heart rate monitoring, and player self-perceived effort. Thirty football players (21.59 ± 4.35 years, 72.74 ± 9.01 kg, and 178.16 ± 0.93 cm) completed 138 recordings during MD-3 sessions (matchday-3, 76 h pre-match) using Catapult OptimEye S5 devices, synchronized with the Polar system. The training structure was similar for all measurements. Analyses and comparisons were made using a total of ten training tasks and six study variables (dimensions, orientation, number of players, directionality, time distribution, and coaches’ feedback). SSGs played as 3 versus 3 showed higher mechanical responses with greater pitch sizes (p 
      Citation: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology
      PubDate: 2023-05-26T10:46:13Z
      DOI: 10.1177/17543371231175946
       
  • Quantifying athlete wellness: Investigating the predictive potential of
           subjective wellness reports through a player monitoring system

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      Authors: Andreas Alexandersen, Susann Dahl Pettersen, Dag Johansen
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology, Ahead of Print.
      This study investigated the potential of self-reported wellness data from a player monitoring system and its predictive power of individual match performance among a female professional football player cohort. Using longitudinal data collected from the Pm Reporter Pro mobile application and corresponding individual performance scores (InStat Index), the study investigated if pre-match perceived wellness could predict individual match performance. The results show no significant evidence for a correlation between the two. This result may suggest that other factors might have a larger impact on performance, that the data quality captured by the current version of the player monitoring system is not sufficient, or that the impact of personally perceived wellness on performance is minimal. The limitations of bias in self-reported data and relatively small sample size might have affected the results. Despite these findings, the study provides valuable insights into the use of data-driven analytics with a concrete and widely used player monitoring system and suggests recommendations for future research.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology
      PubDate: 2023-05-25T11:42:38Z
      DOI: 10.1177/17543371231176625
       
  • Does the operating temperature of accelerometers affect data measurement
           during static and dynamic conditions in sports' A randomized-control trial
           

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      Authors: Carlos D Gómez-Carmona, Daniel Rojas-Valverde, Sergio J Ibáñez, José Pino-Ortega
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology, Ahead of Print.
      This study aimed to analyse the effect of two operating temperatures (optimal vs environmental) on IMU internal temperature and accelerometry-based data in two conditions of measurement: (a) static, no movement; and (b) dynamic, a U’16 game-based training soccer session with 14 players. Each session took a 60-min duration and followed an ecological design (no intervention in environmental conditions). Fifty-six WIMU PROTM inertial devices were randomly grouped in four conditions (two operating temperatures × two measurement conditions, 14 devices in each group) and recorded IMUs’ internal temperature, resultant acceleration vector and PlayerLoad (PLRT). Devices were placed in the manufacturer’s docking station at the static condition and in a specific harness at the interscapular level at the dynamic condition. Repeated measures t-tests were employed for between-group comparisons at 1-min average sections throughout the register. Between-group differences were found in the static and dynamic conditions in IMUs internal temperature (static: 0–31 min; dynamic: 0–20 min) and resultant acceleration vector (static: 0–29 min; dynamic: 0–19 min). Instead, no differences were found in PLRT dynamics and accumulated PLRT although values in the environmental group were overestimated. In conclusion, WIMU PROTM devices must achieve the optimal operating temperature (38–39°) to avoid measurement error, regardless of the application (short or long sessions).
      Citation: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology
      PubDate: 2023-05-17T10:19:56Z
      DOI: 10.1177/17543371231175545
       
  • Validity and reliability of a new portable and cost-effective
           photoelectric cells device for measuring vertical jump performance: “The
           ADR Jumping”

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      Authors: Victor Rodrigo-Carranza, Olga Lopez-Torres, Valentin E Fernandez-Elias, Miguel-Angel Gomez-Ruano, Amelia Guadalupe-Grau
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology, Ahead of Print.
      The vertical jump is one of the most used testing movements to assess athlete’s physical performance and fatigue status in several sports. However, low-cost, portable, field-based, and reliable methods are needed to measure jumping performance. The aim of the current investigation was to assess the validity and reliability of a new photoelectric cells device (ADR) for measuring the vertical jump height. Twenty-three trained male participants (age: 24.8 ± 5.2 years, body mass: 74.2 ± 7.3 kg; height: 1.76 ± 0.04 m) performed four maximal countermovement jumps (CMJ). Flight time-derived jump height was extracted simultaneously from three devices including a force plate (FP) (Kistler Quattro-Jump, criterion measurement) and two photoelectric cells (PC) devices (ADR and Optojump). The ADR mean CMJ height measurements demonstrated substantial validity compared to both FP and Optojump (r = 0.98 p 
      Citation: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology
      PubDate: 2023-05-16T05:54:17Z
      DOI: 10.1177/17543371231174665
       
  • A multi-view automatic table tennis umpiring framework

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      Authors: Patrick Wong, Hnin Myint, Laurence Dooley, Adrian Hopgood
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology, Ahead of Print.
      This paper presents a low-cost, portable, multi-view table tennis umpiring framework, as a viable alternative to the current expensive systems which are almost exclusively restricted to elite professional sports. Table tennis has been selected as the sport to evaluate this framework primarily because it comprises many different complex match elements, including the service, return and rally elements, which are governed by a strict set of regulations which need to be umpired. The aim is to develop novel methods to analyse and judge the legality of such key match facets, with ball detection and tracking in video frames being integral to reliably and accurately determining the ball’s position and flight path during rallies. While a low-cost option is attractive and offers several benefits, it is a technically challenging problem due to the small number and generally low-resolution cameras that are used. A novel multi-view camera setup and multi-agent system (MAS) framework is presented, which comprises computationally lightweight agents which detect and track the table tennis ball, create a 3D representation of the flight path of the ball, predict the ball’s trajectory, and identify and analyse key facets in a table tennis rally. The MAS correctly detects all state transitions in seven test table tennis sequences with minimal latency and while the processing rate of a standard computer may be unable to analyse long rallies in real time, the potential of running the MAS on a parallel architecture is a propitious alternative. The MAS is also scalable, enabling additional camera pairs to be deployed to achieve enhanced accuracy and coverage. The framework affords the potential to reform the way matches are umpired, especially for amateur players, providing an economic and objective manner of dispute resolution, while the multi-view facility is extendible to other relevant ball-based sports. The ball flight path analysis mechanism can be exploited as a valuable training tool for skill development.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology
      PubDate: 2023-04-28T07:21:37Z
      DOI: 10.1177/17543371231171433
       
  • Sight settings for archers shooting up and down hills

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      Authors: James L Park
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology, Ahead of Print.
      Field archery is conducted on an archery course similar in layout to a golf course. Archers shoot at targets placed one after another, usually involving the archers shooting up, down and across slopes. Archers need accurate sight settings if they are to obtain high scores. However, the required sight settings for slopes differ from those on flat ground. One method used by archers is to set the sight to the horizontal distance to the target (the ‘rifleman’s rule’). It has been shown that method does not provide the required precision. It has also been shown that a simple ‘percentage distance cut’ is not viable. An alternative method is provided.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology
      PubDate: 2023-04-24T12:45:25Z
      DOI: 10.1177/17543371231171194
       
  • Validity and reliability of ergonauta encoder to assess countermovement
           jump performance

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      Authors: Rodrigo G Gheller, Rafael L Kons, Wladymir Külkamp, Juliano Dal Pupo, Daniele Detanico
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology, Ahead of Print.
      This study aimed to test the reliability and criterion validity of the Ergonauta encoder to assess countermovement jump (CMJ) performance, considering jump height and mean propulsive velocity metrics. Twenty-three recreationally active men participated in this study. The participants were positioned on a force plate with the Ergonauta individually connected through a belt. Two CMJs were performed, and the jump height and mean propulsive velocity metrics were analyzed. The intraclass correlation coefficient (ICC) and typical error (TE) were used as relative and absolute reliability indicators, respectively. The Pearson correlation was used to verify the relationship between the Ergonauta and force plate derived-metrics, and the Bland-Altman plot was used to verify the agreement between the metrics (Ergonauta encoder and force plate), with the level of significance set at p 
      Citation: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology
      PubDate: 2023-04-24T12:44:05Z
      DOI: 10.1177/17543371231171192
       
  • The influence of technical performance indicators on the results of the
           Chinese Football Super League at different stages of the season-based on
           evidence from the 2010–2019 seasons

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      Authors: Xiaoni Ma, Xiaotian Li, Tao Quan, Hongyou Liu, Tianbiao Liu
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology, Ahead of Print.
      This study explored the different influences of technical indicators on match results in different stages of football league play. Sample data from 2400 Chinese Super League matches during 2010–2019 were divided into three season stages according to round sequence: the early stage (1–10 rounds), the middle stage (11–20 rounds), and the late stage (21–30 rounds). A two-way, fixed-effect ordered logit model was then constructed and used, together with Fisher’s combination test, to compare regression results. The study results showed that: (1) when controlling for other variables, as the league progresses, an increase in goals will gradually increase the possibility of better match results, and this increase shows significant differences between the early and late stages (p 
      Citation: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology
      PubDate: 2023-04-20T06:40:04Z
      DOI: 10.1177/17543371231170065
       
  • Monitoring the external load of counter-attack drills in youth soccer
           using GPS devices: The influence of time pressure and numerical
           superiority on players’ responses

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      Authors: Marcelo Rochael, Gibson Moreira Praça
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology, Ahead of Print.
      This study aimed to analyse the impact of including time pressure on players’ physical responses related to distance covered at different speed zones and accelerations performed during balanced and unbalanced small-sided soccer games. Forty-four U-17 athletes from elite clubs were recruited. Players engaged in four formats of small-sided games: 4vs4 (with and without time pressure) and 5vs4 (with and without time pressure, plus additional floaters). Physical responses were monitored through Global Positioning System devices. A MANOVA compared data at a level of significance of 5%. There were no differences between with and without time pressure formats for both distances and accelerations. However, games played in numerically balanced conditions elicited greater physical responses regarding distance covered and distances covered in different speed zones. Specifically, the numerically balanced condition showed higher distances in the higher speed zones than the floater condition, which showed higher values in the lowest speed zone than the 4vs4 condition. This study concluded that adopting the time pressure to represent counter-attack situations does not change the players’ physical responses; adopting numerical superiority without adjusting the pitch size will reduce the physical responses.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology
      PubDate: 2023-04-15T06:16:26Z
      DOI: 10.1177/17543371231168173
       
  • Concurrent validity of the Polar Precision Prime® photoplethysmographic
           system to measure heart rate during a tennis training session

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      Authors: Emilio J Ruiz-Malagón, Santiago Castro-Infantes, Maximiliano Ritaco-Real, Victor M Soto-Hermoso
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology, Ahead of Print.
      Monitoring heart rates has always been important for coaches and athletes. Photoplet-ismographic systems (PPG) are supposed to be less capable of determining heart rate measure in activities with high upper limb movement, such as tennis. Thus, the aim of this study was to determine the concurrent validity of the Polar Precision Prime® (PPP®) system existing in the Polar Ignite® sports watch. This was accomplished by measuring averaged heart rates during a tennis training session, divided in three parts (warm-up, main-part and cool-down) and averaged per 10 s intervals by comparing data with the Polar H-10® chest strap synchronised with the Polar V800® (criterion measure). A group of 40 tennis players (32 males, 8 females) took part in the study. Mean average values and between-systems differences and Mean Absolute Percentage Error (MAPE) were obtained ( 0.96) in all session parts except the 10 s intervals where the ICC were good (0.85). The systematic bias and random error during the warm-up and 10 s intervals were greater (−0.99 ± 6.02 bpm and −2.41 ± 5.86 bpm, respectively) than the main-part and cool-down (−0.51 ± 1.16 bpm and −0.44 ± 4.02 bpm, respectively). Results suggest that the PPP® system precision is not altered despite upper limb movements during 1-h tennis training sessions. In conclusion, the Polar Ignite® PPG system is a valid tool for monitoring heart rate during a tennis training session.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology
      PubDate: 2023-03-31T10:15:48Z
      DOI: 10.1177/17543371231165102
       
  • Head Impact Exposure in Youth Soccer: Comparing across Activity Types

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      Authors: Nicholas Stewart Pritchard, Tanner M Filben, Sebastian J Haja, Logan E Miller, Mark A Espeland, Joel D Stitzel, Jillian E Urban
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology, Ahead of Print.
      Soccer is a popular youth sport in the United States, but the effect of repetitive head impacts experienced during training on neurocognitive outcomes is not well understood. Modifying practice structure may be an avenue for reducing head impact exposure and concussion risk in soccer, but research has yet to characterize head impact exposure across common soccer activities. The objective of this study was to compare head impact exposure across common training activities in soccer. Eight female soccer players practicing on an age 15 and under (U15) club team participated in this study for two soccer seasons. Players wore an instrumented mouthpiece sensor during all practice and game sessions. Research personnel recorded duration of all activities performed by each player to characterize player-specific exposure time. Film review was performed to identify head contact events during each session and classify events according to the activity and drill the player was performing. Head impact exposure for each athlete was quantified in terms of peak kinematics and impact rate. Mixed effects models were used to compare peak kinematics and generalized linear models were used to compare impact rates across drills and activity type. Drill and activity type were associated with peak kinematics and impact rate. Technical training activities accounted for the second-highest exposure time and were associated with higher impact rates and lower mean kinematics than other activity types. Team interaction activities and game play were associated with the highest rotational kinematics but the lowest impact rates. Head impact exposure in female youth soccer is influenced by the type of activity in which the athlete is engaged. Interventions designed to reduce head impact frequency in female youth soccer can benefit from targeting technical training activities; whereas, interventions designed to reduce head impact magnitude should target team interaction and game activities.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology
      PubDate: 2023-03-13T09:30:17Z
      DOI: 10.1177/17543371231158669
       
  • Acceleration spikes and attenuation response in the trunk in amateur
           tennis players during real game actions

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      Authors: Gabriel Delgado-García, Jos Vanrenterghem, Alejandro Molina-Molina, Víctor Manuel Soto-Hermoso
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology, Ahead of Print.
      Although there are numerous locomotion studies analyzing the degree of attenuation of the acceleration spikes in the lower limbs and the trunk, few of these studies relate to tennis, where a high percentage of injuries occur in these body segments. The aim of this study was to describe the acceleration spikes and the attenuation response along the trunk, in real game actions. For this purpose, accelerometers were placed on the lower trunk, the upper trunk, and the head on a sample of 19 players while playing tennis matches. An average of 530 ± 146 acceleration spikes per match were selected in the upper trunk and a clear attenuation response between the upper trunk and the head was found (acceleration spike magnitude was approximately 25 m/s2 in the upper trunk and approximately 20 m/s2 in the head; p 
      Citation: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology
      PubDate: 2023-03-07T12:37:56Z
      DOI: 10.1177/17543371231157959
       
  • Field-based upper-body motor variability as determinant of stroke
           performance in the main tennis strokes

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      Authors: Emilio J Ruiz-Malagón, Jos Vanrenterghem, Maximiliano Ritacco-Real, Francisco T González-Fernández, Víctor Manuel Soto-Hermoso, Gabriel Delgado-García
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology, Ahead of Print.
      Performance in tennis relies heavily on the skilful repetition of several types of tennis strokes, yet the role of motor variability has still received little scientific attention – especially at the within subject level. The present study aims to evaluate the role of motor variability depending on the strokes/body segment and the level of expertise. Thirty-five players performed a field test (including first and second serves, forehand and backhand strokes) with four synchronized gyroscopes placed on the trunk, head, upper arm and forearm. Variability was measured based on the coefficient of variation (CV) of the angular velocity peaks per stroke in each body segment. MANOVA revealed greater motor variability in the forehand and backhand than in the serve (p  15% in some cases). This result also translated to differences in variability between levels of expertise, with variability being greater among lower level players (p  1 in some cases). Summarized, groundstrokes could imply more compensatory kinematic movements to keep the result of the action stable. Motor variability must be considered to evaluate performance, as a reduced motor variability was found in players with higher level of expertise. The compensatory action of the body segments (especially in groundstrokes and in the forearm and head, where the coefficients of variation were high) should be studied in depth because it can help design motor tasks, making them more specific.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology
      PubDate: 2023-03-01T08:44:47Z
      DOI: 10.1177/17543371231156266
       
  • Analysis of preferred weight configuration for barebow shooting style

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      Authors: Francesco Pietra, Philip Loveday, Robert Reid
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology, Ahead of Print.
      The barebow archery shooting style limits the stabilisation system to weights connected to the riser, which is the central part of the bow. No scientific study is available to guide the barebow archer in the choice of the best weight configuration. In the following work, a human-centred methodology was developed to address this problem from both a scientific and user-oriented perspective. The proposed methodology is based on subjective metrics (archers’ sensations using the equipment), objective metrics (measurable quantities) and precision. The study sought a correlation between the subjective and objective metrics to provide insight into the problem of configuring a bow. Eleven weight configurations were considered. The vibration was measured at five positions on the bow and the 3D dynamic motion was measured using an inertial measurement unit. Seven archers completed a questionnaire to evaluate the subjective shooting sensations. The results show that the two best weight configurations are the 250–200 g and the 350–200 g, at the central and lower attachment points, respectively. A strong correlation exists between the vibration level of the bow and the feeling archers associated with the shooting, and between the dynamic motion of the bow and the comfort of the shooting. No correlation was found between the vibration time and the physical sensations felt by the archers. Determining the influence of the weight configuration on shooting accuracy, with statistical significance, would require an impractically large number of arrows to be shot for each weight configuration. A new methodology was developed to correlate the archers’ physical sensations to measurable parameters and this was applied to understand the barebow weight selection problem. This methodology could be further developed to correlate additional subjective and objective metrics. An understanding of these correlations would allow objective metrics, which can be simulated in the design process, to be used to ensure satisfaction of subjective metrics by the final design.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology
      PubDate: 2023-02-14T09:09:15Z
      DOI: 10.1177/17543371231155510
       
  • Energy loss in oblique collisions

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      Authors: Rod Cross
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology, Ahead of Print.
      The decrease in kinetic energy of a ball incident vertically on a rigid horizontal surface depends on the normal coefficient of restitution, [math]. It is shown in the present paper that if the ball is incident obliquely on the surface then the total decrease in kinetic energy has two independent contributions, one depending on [math], the other depending on the tangential coefficient of restitution, [math].
      Citation: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology
      PubDate: 2023-02-03T12:28:11Z
      DOI: 10.1177/17543371231151794
       
  • Bounce of a golf ball on the green

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      Authors: Rod Cross
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology, Ahead of Print.
      A ball incident on a horizontal surface with backspin can rebound forwards or backwards depending on the angle of incidence and the amount of backspin. The ball can also bounce forwards several times before it bounces backwards. The outcome depends on whether the ball slides throughout the impact or whether the ball grips the surface during the impact. The physics of the bounce of a golf ball on a green is described in the present article and estimates are given of the stopping distance after the ball first lands on the green, based on experimental bounce data.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology
      PubDate: 2023-01-26T11:37:15Z
      DOI: 10.1177/17543371221150289
       
  • Inter-system and inter-unit reliability of Polar Team Pro and WIMU PRO
           devices during external load measurements indoors

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      Authors: Alejandro Rodríguez-Fernández, David Suárez-Iglesias, Alejandro Vaquera, Anthony S Leicht, José Antonio Rodríguez-Marroyo
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology, Ahead of Print.
      The aim was to examine inter-system and inter-unit reliability of both WIMU PRO (UWB) and Polar Team Pro devices in measuring indoor sport-specific movements. Seventeen active and healthy adults (age: 21.4 ± 5.2 years; height 170.3 ± 8.2 cm; body mass: 71.2 ± 4.5 kg) completed one repetition of an indoor team sport circuit (i.e. accelerations, decelerations, change of direction, jumps and arc runs). Participants carried two 10-Hz Polar Team Pro GPS and wore two 20-Hz GPS (UWB) WIMU PRO chest- and back-mounted devices, respectively. Distance (absolute, relative and in different speed thresholds), mean and peak speed, accelerations and decelerations at different intensities and jumps were recorded. A repeated-measures two-way analysis of variance and ICC and CV were utilised. There was a significant (p ≤ 0.001) main effect of the system for all variables except the total distance, mean speed and distance covered during low- and high-intensity running. There were significant differences (p  0.05) between the two WIMU PRO units were detected. Poor inter-system reliability was ascertained, with inter-unit reliability being moderate-excellent for most variables of both systems.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology
      PubDate: 2023-01-26T10:11:44Z
      DOI: 10.1177/17543371221147857
       
  • A trajectory simulation model to analyse the factors influencing the
           descent of a Skeleton athlete

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      Authors: N.S. Vracas, D. Short, J. Banks, D.J. Taunton, S.R. Turnock
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology, Ahead of Print.
      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.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology
      PubDate: 2023-01-20T10:55:55Z
      DOI: 10.1177/17543371221150820
       
  • Parametric design methods development for the comparison of American
           football faceguards using validated structural stiffness models

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      Authors: William D Ferriell, Noah P Wright, John D DesJardins, Gregory S Batt
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology, Ahead of Print.
      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.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology
      PubDate: 2023-01-04T08:57:07Z
      DOI: 10.1177/17543371221140674
       
  • The impact of cross-country skiers’ tucking position on ski-camber
           profile, apparent contact area and load partitioning

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      Authors: Kalle Kalliorinne, Gustav Hindér, Joakim Sandberg, Roland Larsson, Hans-Christer Holmberg, Andreas Almqvist
      Abstract: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology, Ahead of Print.
      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.
      Citation: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology
      PubDate: 2023-01-03T08:55:48Z
      DOI: 10.1177/17543371221141748
       
 
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