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Gaz, Daniel V.

Mayo Clinic

Mayo Clinic

Citations 7

1005 Comparison of Commercially-Available Sleep Tracking Devices With Sleep Diary and Actigraphy
Rieck, Thomas , Gaz, Daniel V., Peterson, Nolan W., Jenkins, Sarah M. , Rosedahl, Jordan K., Krzoska, Ashley A, Clark, Matthew M. , Hagen, Philip T., Mansukhani, Meghna P. , Kolla, Bhanu Prakash , Morgenthaler, Timothy I.

Sleep | April 13, 2019 | Volume: 42 | Issue: Supplement_1 | Pages: A404-A405

10.1093/sleep/zsz067.1002 Get It

Determining the Validity and Accuracy of Multiple Activity-Tracking Devices in Controlled and Free-Walking Conditions
Gaz, Daniel V., Rieck, Thomas , Peterson, Nolan W., Ferguson, Jennifer A., Schroeder, Darrell R. , Dunfee, Heather A., Henderzahs-Mason, Jill M., Hagen, Philip T., Rieck, Thomas M, Schroeder, Darrell

American Journal of Health Promotion | March 21, 2018 | Volume: 32 | Issue: 8 | Pages: 1671-1678

10.1177/0890117118763273 Get It

Purpose: Clinicians and fitness professionals are increasingly recommending the use of activity trackers. This study compares commercially available activity tracking devices for step and distance accuracy in common exercise settings. Design: Cross sectional. Setting: Rochester, Minnesota. Participants: Thirty-two men (n = 10) and women (n = 22) participated in the study. Measures: Researchers manually counted steps and measured distance for all trials, while participants wore 6 activity tracking devices that measured steps and distance. Analysis: We computed the difference between the number of steps measured by the device and the actual number of steps recorded by the observers, as well as the distance displayed by the device and the actual distance measured. Results: The analyses showed that both the device and walking trials affected the accuracy of the results (steps or distance, P < .001). Hip-based devices were more accurate and consistent for measuring step count. No significant differences were found among devices or locations for the distance measured. Conclusions: Hip-based activity tracking devices varied in accuracy but performed better than their wrist-based counterparts for step accuracy. Distance measurements for both types of devices were more consistent but lacked accuracy.
Interpreting oblique impact data from an accelerometer-instrumented ice hockey helmet
Jorgensen, Janelle, Thoreson, Andrew R. , Stuart, Michael, Loyd, Andre M., Smith, Aynsley M., Twardowski, Casey P., Gaz, Daniel V., Hollman, John H. , An, Kai , Krause, David A. , An, Kai Nan, Stuart, Michael J. , Hollman, John

Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology | April 7, 2017 | Volume: 231 | Issue: 4 | Pages: 307-316

10.1177/1754337117700549 Get It

The purpose of this study was to assess the correlations of acceleration measurements between an instrumented hockey helmet and the Hybrid III headform and to determine whether collision with a broad surface affects the correlations between these data. A CCM Vector hockey helmet, instrumented with the Head Impact Telemetry System, was fitted onto an instrumented Hybrid III headform and dropped onto an inclined plate to simulate impacts in hockey. The helmet and headform were dropped from 0.15, 0.30, and 0.60 m at different orientations to create impacts to the vertex, occipital, right, left, and forehead surfaces. Peak linear and rotational acceleration magnitudes and head injury criteria were assessed for each system. Correlations were assessed with the Pearson correlation coefficient, and linear regression models were generated. Relative error was assessed, and results were compared with the Wilcoxon signed rank test. Peak acceleration magnitudes generally had strong mathematical correlations, although a 1:1 linear relationship for rotational acceleration data was not observed. Differences between helmet and head peak acceleration magnitudes were significant. The linear relationship varied according to the impact direction. Instrumented helmet and head data demonstrated a strong mathematical correlation, but measures of linear acceleration generally had better 1:1 agreement than rotational acceleration measures. There is some dependence in the relationship between the helmet and head data on the impact direction, with vertex strikes showing the weakest correlation. Although data generated from the helmet may be useful for interpreting head accelerations experienced by on-ice players, additional analysis of the time-series data should be performed to understand its full utility.
Does fair play reduce concussions? A prospective, comparative analysis of competitive youth hockey tournaments
Smith, Aynsley M., Gaz, Daniel V., Jorgensen, Janelle, Eickhoff, Chad, Fenske, Brooke M, Aney, Katie, Hansen, Ashley, Nanos, Stephanie , Larson, Dirk, Jorgensen, Janelle K, Hansen, Ashley A, Nanos, Stephanie M, Larson, Dirk R. , Krause, David A. , Fenske, BM, Stuart, Michael J.

BMJ Open Sport & Exercise Medicine | November 22, 2016 | Volume: 2 | Issue: 1 | Pages: e000074

10.1136/bmjsem-2015-000074 Get It

Background/aim To determine if Boys Bantam and Peewee and Girls U14 sustain fewer concussions, head hits, ‘other injuries’ and penalties in hockey tournaments governed by intensified fair play (IFP) than non-intensified fair play (NIFP). Methods A prospective comparison of IFP, a behaviour modification programme that promotes sportsmanship, versus control (non-intensified, NIFP) effects on numbers of diagnosed concussions, head hits without diagnosed concussion (HHWDC), ‘other injuries’, number of penalties and fair play points (FPPs). 1514 players, ages 11–14 years, in 6 IFP (N=950) and 5 NIFP (N=564) tournaments were studied. Results Two diagnosed concussions, four HHWDC, and six ‘other injuries’ occurred in IFP tournaments compared to one concussion, eight HHWDC and five ‘other injuries’ in NIFP. There were significantly fewer HHWDC in IFP than NIFP (p=0.018). However, diagnosed concussions, ‘other injuries’, penalties and FPPs did not differ significantly between conditions. In IFP, a minority of teams forfeited the majority of FPPs. Most diagnosed concussions, HHWDC, and other injuries occurred to Bantam B players and usually in penalised teams that forfeited their FPPs. Conclusions In response to significant differences in HHWDC between IFP and NIFP tournaments, the following considerations are encouraged: mandatory implementation of fair play in regular season and tournaments, empowering tournament directors to not accept heavily penalised teams, and introducing ‘no body checking’ in Bantam.
Hockey Education Program: Fair Play Implementation Issues and a Feasible Solution
Smith, Aynsley M., Twardowski, Casey P., Gaz, Daniel V., Margenau, Dave, Stuart, Michael J.

Mechanism of Concussion in Sports | April 11, 2014 | Volume: No volume available | Issue: No issue available | Pages: 234-245

10.1520/stp155220120185 Get It

The Minnesota Hockey Education Program (HEP) has three components: skill development, coaching excellence, and Fair Play. The purpose of this paper, however, is to discuss Fair Play, its implementation, success, challenges, and propose a feasible solution. The data collected on Fair Play points earned and decreases in specific penalties suggests positive outcomes attributable to Fair Play, an evidence based program that emphasizes sportsmanship. Closer inspection reveals uneven implementation manifested by: (i) a failure to mandate that invitational tournaments be governed by Fair Play, (ii) not publicizing the influence Fair Play has on determining positioning for end of the season standings, and (iii) the inability to continually promote Fair Play to the continuous turnover of players, parents, and coaches. Annual attrition of a generation of hockey players, parents, and coaches involved when Fair Play was launched contributes to the current lack of awareness about the program. This situation was occurring at the same time we became aware that the prevalence of injuries, such as concussion, had escalated. The less than optimal status of the Fair Play program is not attributed to a lack of effort, but to the fact that volunteer organizations may lack the necessary infrastructure to disseminate information adequately and continuously. A potential solution to the Fair Play knowledge gap is a volunteer safety parent for each team. This parent would be responsible for safety information dissemination (CDC, HUDD, and Fair Play manuals), tracking Fair Play points, ensuring they are posted on the websites, and politely reminding coaches to introduce or review the appropriate on-ice skills training for safety zones, giving and receiving checks, and Head’s Up Don’t Duck (HUDD).
Epidemiology of Ice Hockey Injury Research Using Reliable Exposure Time Software
Twardowski, Casey P., Smith, Aynsley M., Gaz, Daniel V., Larson, Dirk R. , Stuart, Michael J.

Mechanism of Concussion in Sports | March 20, 2014 | Volume: No volume available | Issue: No issue available | Pages: 208-216

10.1520/stp155220120153 Get It

A significant issue in research on the epidemiology of injury relates not to the numerator (injury), but to the denominator: exposure time. Most hockey injury studies “assume” equivalent playing time. This assumption is not problematic for large investigations designed to establish differences in concussion rates between levels of participation. However, the assumption is a serious issue when investigators are testing differences in rules, coaching programs, skills training, and behavioral interventions. Because players are at higher risk for injuries when fatigued, individual exposure time is important. Until recently, analyzing individual playing times for ice hockey teams has been a daunting task, as it involved the hand-written recording of times using a grid and check marks. During the 2011–2012 season, a computer-based program, Time on Ice (TOI), was used to expedite the accurate recording of individual exposure, including shorthanded and power-play situations. The purpose of using TOI software in this study was to ensure that its results were in agreement with the exposure times recorded manually using a paper-and-pencil grid. Preliminary results from six games (12 records of data) showed that exposure time ranged from 6.3 to 26.4 min when using manual recording and 8.3 to 33.2 min when using TOI. These methods were concluded to be in agreement. Now that software has been developed exclusively for the task of tracking time on ice, it is recommended that exposure time be measured when injuries such as concussion are being evaluated and causation is being determined. The Sport Performance Analyzer TOI system is commercially available.
Catastrophic Ice Hockey Registry: USA Hockey and Mayo Clinic
Gaz, Daniel V., Stuart, Michael J.

Mechanism of Concussion in Sports | March 20, 2014 | Volume: No volume available | Issue: No issue available | Pages: 219-233

10.1520/stp155220120149 Get It

Catastrophic injuries in the sport of ice hockey are rare but result in life-altering conditions such as paralysis and cognitive impairment, or even death. Potentially catastrophic injuries without permanent functional disability are also a serious concern. In 2006, Mayo Clinic Sports Medicine Center and USA Hockey established a registry for catastrophic and potentially catastrophic injuries sustained by ice hockey players in the Unites States. Since data collection began in 2008, our research team has acquired 45 database entries obtained from self-reports, Google Alerts (using the term “hockey injury”), and the National Electronic Injury Surveillance System. Cervical fracture and neck laceration were the most common types of injuries, with the spine and head being the most commonly injured body parts. Steps to reduce the aforementioned injury types and locations include USA Hockey's “Heads Up, Do Not Duck” program and increased use and awareness of neck laceration protectors.