scholarly journals Validity of a Local Positioning System during Outdoor and Indoor Conditions for Team Sports

Sensors ◽  
2020 ◽  
Vol 20 (20) ◽  
pp. 5733
Author(s):  
Prisca S. Alt ◽  
Christian Baumgart ◽  
Olaf Ueberschär ◽  
Jürgen Freiwald ◽  
Matthias W. Hoppe
Keyword(s):  
Team Sports ◽  
Team Sport ◽  
Positioning System ◽  
Typical Error ◽  
Local Positioning System ◽  
Filtering Technique ◽  
Indoor Conditions ◽  
The Impact ◽  
And Training ◽  
Tracking Technology

This study aimed to compare the validity of a local positioning system (LPS) during outdoor and indoor conditions for team sports. The impact of different filtering techniques was also investigated. Five male team sport athletes (age: 27 ± 2 years; maximum oxygen uptake: 48.4 ± 5.1 mL/min/kg) performed 10 trials on a team sport-specific circuit on an artificial turf and in a sports hall. During the circuit, athletes wore two devices of a recent 20-Hz LPS. From the reported raw and differently filtered velocity data, distances covered during different walking, jogging, and sprinting sections within the circuit were computed for which the circuit was equipped with double-light timing gates as criterion measures. The validity was determined by comparing the known and measured distances via the relative typical error of estimate (TEE). The LPS validity for measuring distances covered was good to moderate during both environments (TEE: 0.9–7.1%), whereby the outdoor validity (TEE: 0.9–6.4%) was superior than indoor validity (TEE: 1.2–7.1%). During both environments, validity outcomes of an unknown manufacturer filter were superior (TEE: 0.9–6.2%) compared to those of a standard Butterworth filter (TEE: 0.9–6.4%) and to unprocessed raw data (TEE: 1.0–7.1%). Our findings show that the evaluated LPS can be considered as a good to moderately valid tracking technology to assess running-based movement patterns in team sports during outdoor and indoor conditions. However, outdoor was superior to indoor validity, and also impacted by the applied filtering technique. Our outcomes should be considered for practical purposes like match and training analyses in team sport environments.

scholarly journals Validation of Player and Ball Tracking with a Local Positioning System

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1465
Author(s):  
Patrick Blauberger ◽  
Robert Marzilger ◽  
Martin Lames
Keyword(s):  
Reference System ◽  
Team Sports ◽  
Infrared Camera ◽  
Positioning System ◽  
Tracking Errors ◽  
Position Errors ◽  
Position Detection ◽  
Player Tracking ◽  
Local Positioning System ◽  
Ball Tracking

The aim of this study was the validation of player and ball position measurements of Kinexon’s local positioning system (LPS) in handball and football. Eight athletes conducted a sport-specific course (SSC) and small sided football games (SSG), simultaneously tracked by the LPS and an infrared camera-based motion capture system as reference system. Furthermore, football shots and handball throws were performed to evaluate ball tracking. The position root mean square error (RMSE) for player tracking was 9 cm for SSCs, the instantaneous peak speed showed a percentage deviation from the reference system of 0.7–1.7% for different exercises. The RMSE for SSGs was 8 cm. Covered distance was overestimated by 0.6% in SSCs and 1.0% in SSGs. The 2D RMSE of ball tracking was 15 cm in SSGs, 3D position errors of shot and throw impact locations were 17 cm and 21 cm. The methodology for the validation of a system’s accuracy in sports tracking requires extensive attention, especially in settings covering both, player and ball measurements. Most tracking errors for player tracking were smaller or in line with errors found for comparable systems in the literature. Ball tracking showed a larger error than player tracking. Here, the influence of the positioning of the sensor must be further reviewed. In total, the accuracy of Kinexon’s LPS has proven to represent the current state of the art for player and ball position detection in team sports.

scholarly journals Is It High Time to Increase Elite Soccer Substitutions Permanently?

2020 ◽  
Vol 17 (19) ◽  
pp. 7008
Author(s):  
Gustavo R. Mota ◽  
Izabela Aparecida dos Santos ◽  
Rhaí André Arriel ◽  
Moacir Marocolo
Keyword(s):  
Substitution Rate ◽  
Team Sports ◽  
Injury Rate ◽  
Higher Dimensions ◽  
Team Sport ◽  
High Time ◽  
Injury Incidence ◽  
Physical Demands ◽  
The Impact

Rules determine how team sport matches occur. Match-induced fatigue is specific to each sport, and may be associated with injury incidence. For example, the injury rate in soccer is distinctly higher during matches than in training sessions. Understanding the differences between team sports rules might be useful for enhancing rules (e.g., safer sport). Therefore, this study aimed to evaluate the impact of the rule-induced physical demands between soccer, futsal, basketball, and handball, focusing on substitution rules. Data from the elite team sports’ rules (e.g., absolute and relative court dimensions; the number of players, substitutions allowed, total game time, time-outs) were collected, including the changes due to the coronavirus disease (COVID-19) pandemic in soccer substitutions, and comparisons were performed. The data showed that soccer has higher rule-induced physical demands: e.g., substantially lower substitution rate, higher dimensions in absolute (eight to fifteen times), and relative (four to eight times) values. Simulations also showed that soccer has extremely large differences, even considering COVID-19 substitution changes (from three to up to five). We conclude that elite soccer has remarkably higher overall rule-induced physical demands than elite futsal, basketball and handball, and increasing soccer substitutions permanently (e.g., unlimited) might mitigate overall soccer demands.

scholarly journals A Signal Recovery Method Based on Bayesian Compressive Sensing

2019 ◽  
Vol 2019 ◽  
pp. 1-13
Author(s):  
Hao Zhanjun ◽  
Li Beibei ◽  
Dang Xiaochao
Keyword(s):  
Compressive Sensing ◽  
Human Body ◽  
Positioning System ◽  
Complex Environments ◽  
Positioning Accuracy ◽  
Recovery Method ◽  
Positioning Systems ◽  
Local Positioning System ◽  
Crawling Waves ◽  
The Impact

In a precise positioning system, weak signal errors caused by the influence of a human body on signal transmission in complex environments are a main cause of the reduced reliability of communication and positioning accuracy. Therefore, eliminating the influence of interference from human crawling waves on signal transmissions in complex environments is an important task in improving positioning systems. To conclude, an experimental environment is designed in this paper and a method using the Ultra-Wideband (UWB) Local Positioning System II (UWB LPS), called Bayesian Compressed Sensing-Crawling Waves (BCS-CW), is proposed to eliminate the impact of crawling waves using Bayesian compressive sensing. First, analyse the transmission law for crawling waves on the human body. Second, Bayesian compressive sensing is used to recover the UWB crawling wave signal. Then, the algorithm is combined with the maximum likelihood estimation and iterative approximation algorithms to determine the label position. Finally, through experimental verification, the positioning accuracy of this method is shown to be greatly improved compared to that of other algorithms.

scholarly journals The Research Doesn’t Always Apply: Practical Solutions to Evidence-Based Training-Load Monitoring in Elite Team Sports

2017 ◽  
Vol 12 (s2) ◽  
pp. S2-136-S2-141 ◽  
Author(s):  
Darren J. Burgess
Keyword(s):  
External Load ◽  
Team Sports ◽  
Reliability And Validity ◽  
Team Sport ◽  
Evidence Based ◽  
Internal Load ◽  
Professional Team Sports ◽  
Load Monitoring ◽  
Player Performance ◽  
The Impact

Research describing load-monitoring techniques for team sport is plentiful. Much of this research is conducted retrospectively and typically involves recreational or semielite teams. Load-monitoring research conducted on professional team sports is largely observational. Challenges exist for the practitioner in implementing peer-reviewed research into the applied setting. These challenges include match scheduling, player adherence, manager/coach buy-in, sport traditions, and staff availability. External-load monitoring often attracts questions surrounding technology reliability and validity, while internal-load monitoring makes some assumptions about player adherence, as well as having some uncertainty around the impact these measures have on player performance This commentary outlines examples of load-monitoring research, discusses the issues associated with the application of this research in an elite team-sport setting, and suggests practical adjustments to the existing research where necessary.

scholarly journals Development of a Simulated Round of Golf

2009 ◽  
Vol 4 (4) ◽  
pp. 506-516 ◽  
Author(s):  
Philip R. Hayes ◽  
Kjell van Paridon ◽  
Duncan N. French ◽  
Kevin Thomas ◽  
Dan A. Gordon
Keyword(s):  
Heart Rate ◽  
Global Positioning System ◽  
Physiological Responses ◽  
Gps Data ◽  
Positioning System ◽  
Typical Error ◽  
Global Positioning ◽  
The Mean ◽  
Physiological Demands ◽  
The Impact

Purpose:The aim of this study was to develop a laboratory-based treadmill simulation of the on-course physiological demands of an 18-hole round of golf and to identify the underlying physiological responses.Methods:Eight amateur golfers completed a round of golf during which heart rate (HR), steps taken, and global positioning system (GPS) data were assessed. The GPS data were used to create a simulated discontinuous round on a treadmill. Steps taken and HR were recorded during the simulated round.Results:During the on-course round, players covered a mean (±SD) of 8,251 ± 450 m, taking 12,766 ± 1,530 steps. The mean exercise intensity during the on-course round was 31.4 ± 9.3% of age-predicted heart rate reserve (%HRR) or 55.6 ± 4.4% of age-predicted maximum HR (%HRmax). There were no significant differences between the simulated round and the on-course round for %HRR (P = .537) or %HR max (P = .561) over the entire round or for each individual hole. Furthermore, there were no significant differences between the two rounds for steps taken. Typical error values for steps taken, HR, %HRmax, and %HRR were 1,083 steps, ±7.6 b·min-1, ±4.5%, and ±8.1%, respectively.Conclusion:Overall, the simulated round of golf successfully recreated the demands of an on-course round. This simulated round could be used as a research tool to assess the extent of fatigue during a round of golf or the impact of various interventions on golfers.

scholarly journals The Validity and Reliability of 1-Hz and 5-Hz Global Positioning Systems for Linear, Multidirectional, and Soccer-Specific Activities

2010 ◽  
Vol 5 (4) ◽  
pp. 448-458 ◽  
Author(s):  
Matthew D. Portas ◽  
Jamie A. Harley ◽  
Christopher A. Barnes ◽  
Christopher J. Rush
Keyword(s):  
Confidence Intervals ◽  
Global Positioning System ◽  
Team Sports ◽  
Positioning System ◽  
Validity And Reliability ◽  
Activity Data ◽  
Positioning Systems ◽  
Typical Error ◽  
Global Positioning ◽  
Measured Distance

Purpose:The study aimed to analyze the validity and reliability of commercially available nondifferential Global Positioning System (NdGPS) devices for measures of total distance during linear, multidirectional and soccer-specific motion at 1-Hz and 5-Hz sampling frequencies.Methods:Linear (32 trials), multidirectional (192 trials) and soccer-specific courses (40 trials) were created to test the validity (mean ± 90% confidence intervals), reliability (mean ± 90% confidence intervals) and bias (mean ± 90% confidence intervals) of the NdGPS devices against measured distance. Standard error of the estimate established validity, reliability was determined using typical error and percentage bias was established.Results:The 1-Hz and 5-Hz data ranged from 1.3% ± 0.76 to 3.1% ± 1.37 for validity and 2.03% ± 1.31 to 5.31% ± 1.2 for reliability for measures of linear and soccer-specific motion. For multidirectional activity, data ranged from 1.8% ± 0.8 to 6.88% ± 2.99 for validity and from 3.08% ± 1.34 to 7.71% ± 1.65 for reliability. The 1-Hz underestimated some complex courses by up to 11%.Conclusions:1-Hz and 5-Hz NdGPS could be used to quantify distance in soccer and similar field-based team sports. Both 1-Hz and 5-Hz have a threshold beyond which reliability is compromised. 1-Hz also underestimates distance and is less valid in more complex courses.

scholarly journals Criterion Validity of Catapult ClearSky T6 Local Positioning System for Measuring Inter-Unit Distance

Sensors ◽  
2020 ◽  
Vol 20 (13) ◽  
pp. 3693 ◽  
Author(s):  
Ryan W. Hodder ◽  
Kevin A. Ball ◽  
Fabio R. Serpiello
Keyword(s):  
Root Mean Square Error ◽  
Mean Square Error ◽  
Root Mean Square ◽  
Team Sport ◽  
Positioning System ◽  
Mean Square ◽  
Unit Distance ◽  
Change Of Direction ◽  
Player Tracking ◽  
Local Positioning System

The validity of a local positioning system (LPS) to measure inter-unit distance was investigated during a team sport movement circuit. Eight recreationally active, female indoor team-sport players completed a circuit, comprising seven types of movements (walk, jog, jump, sprint, 45° change of direction and shuffle), on an indoor court. Participants wore a receiver tag (ClearSky T6, Catapult Sports) and seven reflective markers, to allow for a comparison with the reference system (©Vicon Motion Systems, Oxford Metrics, UK). Inter-unit distance was collected for each combination of participants. Validity was assessed via root mean square error, mean bias and percentage of variance accounted for, both as an overall dataset and split into distance bands. The results presented a mean root mean square error of 0.20 ± 0.05 m, and mean bias detected an overestimation for all distance bands. The LPS shows acceptable accuracy for measuring inter-unit distance, opening up opportunities to utilise player tracking for tactical variables indoors.

Voices of Distress: The Emotional Peril of Not Attaining a Dietetic Internship in Ontario

2013 ◽  
Vol 1 (3) ◽  
pp. 9
Author(s):  
Jennifer Lee Brady ◽  
Annie Hoang ◽  
Olivia Siswanto ◽  
Jordana Riesel ◽  
Jacqui Gingras
Keyword(s):  
Empirical Research ◽  
Current Model ◽  
Well Being ◽  
Structured Interview ◽  
Application Process ◽  
Dietetic Education ◽  
Dietetic Internship ◽  
The Impact ◽  
And Training ◽  
Future Growth

Obtaining dietetic licensure in Ontario requires completion of a Dietitians of Canada (DC) accredited four-year undergraduate degree in nutrition and an accredited post-graduate internship or combined Master’s degree program. Given the scarcity of internship positions in Ontario, each year approximately two-thirds of the eligible applicants who apply do not receive a position XX, XX, XX, XX, XX, XX, in press). Anecdotally, not securing an internship position is known to be a particularly disconcerting experience that has significant consequences for individuals’ personal, financial, and professional well-being. However, no known empirical research has yet explored students’ experiences of being unsuccessful in applying for internship positions. Fifteen individuals who applied between 2005 and 2009 to an Ontario-based dietetic internship program, but were unsuccessful at least once, participated in a one-on-one semi-structured interview. Findings reveal that participants’ experiences unfold successively in four phases that are characterized by increasingly heightened emotional peril: naïveté, competition, devastation, and frustration. The authors conclude that the current model of dietetic education and training in Ontario causes lasting distress to students and hinders the future growth and vitality of the dietetic profession. Further research is required to understand the impact of the current model on dietetic educators, internship coordinators, and preceptors as coincident participants in the internship application process.

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