Validity and reliability of an accelerometer-based player tracking device

<div><p>This study aimed to determine the intra- and inter-device accuracy and reliability of wearable athletic tracking devices, under controlled laboratory conditions. A total of nineteen portable accelerometers (Catapult OptimEye S5) were mounted to an aluminum bracket, bolted directly to an Unholtz Dickie 20K electrodynamic shaker table, and subjected to a series of oscillations in each of three orthogonal directions (front-back, side to side, and up-down), at four levels of peak acceleration (0.1g, 0.5g, 1.0g, and 3.0g), each repeated five times resulting in a total of 60 tests per unit, for a total of 1140 records. Data from each accelerometer was recorded at a sampling frequency of 100Hz. Peak accelerations recorded by the devices, Catapult PlayerLoad™, and calculated player load (using Catapult’s Cartesian formula) were used for the analysis. The devices demonstrated excellent intradevice reliability and mixed interdevice reliability. Differences were found between devices for mean peak accelerations and PlayerLoad™ for each direction and level of acceleration. Interdevice effect sizes ranged from a mean of 0.54 (95% CI: 0.34–0.74) (small) to 1.20 (95% CI: 1.08–1.30) (large) and ICCs ranged from 0.77 (95% CI: 0.62–0.89) (very large) to 1.0 (95% CI: 0.99–1.0) (nearly perfect) depending upon the magnitude and direction of the applied motion. When compared to the player load determined using the Cartesian formula, the Catapult reported PlayerLoad™ was consistently lower by approximately 15%. These results emphasize the need for industry wide standards in reporting validity, reliability and the magnitude of measurement errors. It is recommended that device reliability and accuracy are periodically quantified.</p></div

RELATIONSHIP BETWEEN KINEMATIC CHARACTERISTICS AND FREE-THROW SHOOTING PRECISION: MARKERLESS MOTION CAPTURE ANALYSIS

The search for aspects of basketball shooting that characterize successful performance is an area of focus for sports biomechanists. However, the systematic evaluation of these key elements during shooting practice is limited due to the time it takes to collect and/or process the data. Thus, the purpose of the present study was to evaluate the relationship between some of the key kinematic variables extracted from a markerless motion capture system on free-throw shot performance. Multivariable linear regression analysis indicated that shot plane alignment, trunk rotation, entry angle, and timing of elbow extension were some of the key contributors to free-throw shot precision. Overall, these kinematic variables serve as a preliminary set of outcomes that can be reported to coaches and players that decide to use markerless motion capture technology for free-throw shooting biomechanical analysis

TENA in a Telemetry Network System

ITC/USA 2008 Conference Proceedings / The Forty-Fourth Annual International Telemetering Conference and Technical Exhibition / October 27-30, 2008 / Town and Country Resort & Convention Center, San Diego, CaliforniaThe integrated Network Enhanced Telemetry (iNET) and Test and Training Enabling Architecture (TENA) projects are working to understand how TENA will perform in a Telemetry Network System. This paper discusses a demonstration prototype that is being used to investigate the use of TENA across a constrained test environment simulating iNET capabilities. Some of the key elements being evaluated are throughput, latency, memory utilization, memory footprint, and bandwidth. The results of these evaluations will be presented. Additionally, the paper briefly discusses modeling and metadata requirements for TENA and iNET.International Foundation for TelemeteringProceedings from the International Telemetering Conference are made available by the International Foundation for Telemetering and the University of Arizona Libraries. Visit http://www.telemetry.org/index.php/contact-us if you have questions about items in this collection

TENA Performance in a Telemetry Network System

ITC/USA 2009 Conference Proceedings / The Forty-Fifth Annual International Telemetering Conference and Technical Exhibition / October 26-29, 2009 / Riviera Hotel & Convention Center, Las Vegas, NevadaThe integrated Network-Enhanced Telemetry (iNET) project conducted an assessment to determine how the Test and Training Enabling Architecture (TENA) would integrate into an iNET Telemetry Network System (TmNS), particularly across constrained environments on a resource constrained platform. Some of the key elements investigated were quality of service measures (throughput, latency, and reliability) in the face of projected characteristics of iNET Data Acquisition Unit (DAU) devices including size, weight, and power (SWAP), and processing capacity such as memory size and processor speed. This paper includes recommendations for both the iNET and TENA projects.International Foundation for TelemeteringProceedings from the International Telemetering Conference are made available by the International Foundation for Telemetering and the University of Arizona Libraries. Visit http://www.telemetry.org/index.php/contact-us if you have questions about items in this collection

Technology Trades for Management of Telemetry Network Systems

ITC/USA 2008 Conference Proceedings / The Forty-Fourth Annual International Telemetering Conference and Technical Exhibition / October 27-30, 2008 / Town and Country Resort & Convention Center, San Diego, CaliforniaThe Integrated Network Enhanced Telemetry (iNET) Project established a standards working group to address the integrated management of telemetry network systems and to ensure interoperability among various pieces of equipment. The group has been studying the benefits and drawbacks of various system management technologies with the goal of identifying a set of management interfaces which will provide long-range benefit to a large and diverse telemetry test system. This paper discusses control, configuration, status, performance, and fault management. It addresses these from several viewpoints such as multi-test articles, multi-ranges, and dynamic test environments.International Foundation for TelemeteringProceedings from the International Telemetering Conference are made available by the International Foundation for Telemetering and the University of Arizona Libraries. Visit http://www.telemetry.org/index.php/contact-us if you have questions about items in this collection

Mean catapult PlayerLoad™ (PL) from five repeats with 95% confidence intervals.

<p>For clarity only 5 devices are shown (3g peak acceleration, 8 Hz). Please see Supporting Information for complete data set (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0191823#pone.0191823.s001" target="_blank">S1 Data</a>).</p

Accelerometer test matrix.

<p>Accelerometer test matrix.</p

Peak acceleration interdevice effect sizes (Cohen’s d).

<p>Peak acceleration interdevice effect sizes (Cohen’s d).</p

Catapult player Load^™ interdevice effect sizes (Cohen’s d).

<p>Catapult player Load^™ interdevice effect sizes (Cohen’s d).</p

Descriptive statistics: 3.0 g, 8 Hz applied peak acceleration.

<p>Data for 0.1g, 0.5g and 1.0g applied acceleration can be found in the Supporting Information.</p