An assessment of the utility and functionality of wearable head impact sensors in Australian Football
- Authors: McIntosh, Andrew , Willmott, Catherine , Patton, Declan , Mitra, Biswadev , Brennan, James , Dimech-Betancourt, Bleydy , Howard, Teresa , Rosenfeld, Jeffrey
- Date: 2019
- Type: Text , Journal article
- Relation: Journal of Science and Medicine in Sport Vol. 22, no. 7 (2019), p. 784-789
- Full Text: false
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- Description: Objectives: To assess the utility and functionality of the X-Patch® as a measurement tool to study head impact exposure in Australian Football. Accuracy, precision, reliability and validity were examined. Designs: Laboratory tests and prospective observational study. Methods: Laboratory tests on X-Patch® were undertaken using an instrumented Hybrid III head and neck and linear impactor. Differences between X-Patch® and reference data were analysed. Australian Football players wore the X-Patch® devices and games were video-recorded. Video recordings were analysed qualitatively for head impact events and these were correlated with X-Patch® head acceleration events. Wearability of the X-Patch® was assessed using the Comfort Rating Scale for Wearable Computers. Results: Laboratory head impacts, performed at multiple impact sites and velocities, identified significant correlations between headform-measured and device-measured kinematic parameters (p < 0.05 for all). On average, the X-Patch®-recorded peak linear acceleration (PLA) was 17% greater than the reference PLA, 28% less for peak rotational acceleration (PRA) and 101% greater for the Head Injury Criterion (HIC). For video analysis, 118 head acceleration events (HAE) were included with PLA ≥30 g across 53 players. Video recordings of X-Patch®-measured HAEs (PLA ≥30 g) determined that 31.4% were direct head impacts, 9.3% were indirect impacts, 44.1% were unknown or unclear and 15.3% were neither direct nor indirect head impacts. The X-Patch® system was deemed wearable by 95–100% of respondents. Conclusions: This study reinforces evidence that use of the current X-Patch® devices should be limited to research only and in conjunction with video analysis.
Reconstruction of head impacts in FIS World Cup alpine skiing
- Authors: Steenstrup, Sophie , Mok, Kam-Ming , McIntosh, Andrew , Bahr, Roald , Krosshaug, Tron
- Date: 2018
- Type: Text , Journal article
- Relation: British Journal of Sports Medicine Vol. 52, no. 11 (2018), p. 709-715
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- Description: Introduction Prior to the 2013/2014 season, the International Ski Federation (FIS) increased the helmet testing speed from 5.4 to 6.8 m/s for alpine downhill, super-G and giant slalom. Whether this increased testing speed reflects head impact velocities in real head injury situations on snow is unclear. We therefore investigated the injury mechanisms and gross head impact biomechanics in seven real head injury situations among World Cup (WC) alpine skiers. Methods We analysed nine head impacts from seven head injury videos from the FIS Injury Surveillance System, throughout nine WC seasons (2006-2015) in detail. We used commercial video-based motion analysis software to estimate head impact kinematics in two dimensions, including directly preimpact and postimpact, from broadcast video. The sagittal plane angular movement of the head was also measured using angle measurement software. Results In seven of nine head impacts, the estimated normal to slope preimpact velocity was higher than the current FIS helmet rule of 6.8 m/s (mean 8.1 (±SD 0.6) m/s, range 1.9±0.8 to 12.1±0.4 m/s). The nine head impacts had a mean normal to slope velocity change of 9.3±1.0 m/s, range 5.2±1.1 to 13.5±1.3 m/s. There was a large change in sagittal plane angular velocity (mean 43.3±2.9 rad/s (range 21.2±1.5 to 64.2±3.0 rad/s)) during impact. Conclusion The estimated normal to slope preimpact velocity was higher than the current FIS helmet rule of 6.8 m/s in seven of nine head impacts.
Shoulder injuries in elite rugby union football matches : Epidemiology and mechanisms
- Authors: Usman, Juliana , McIntosh, Andrew , Quarrie, Kenneth , Targett, Stephen
- Date: 2015
- Type: Text , Journal article
- Relation: Journal of Science and Medicine in Sport Vol. 18, no. 5 (2015), p. 529-533
- Full Text: false
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- Description: Objectives: Shoulder injuries in rugby union football have been the focus of few in-depth studies, despite their frequency and severity. The study's objective was to describe the incidence, patterns and mechanisms of shoulder injuries in rugby. Design: Prospective cohort study of shoulder injury incidence and retrospective case-series study of shoulder injury mechanisms. Methods: Data were collected from Super Rugby matches from 2005 to 2010 involving elite level adult male rugby players. Results: 7920 player participation hours and 100 shoulder injuries were recorded during 397 Super Rugby matches. The shoulder injury incidence rate was 13 per 1000 player hours (95% confidence interval 10-16). The mean number of days unavailable for selection due to these injuries was 37 (95% confidence interval 25-54). Tacklers sustained shoulder injuries at a higher rate than ball carriers (Rate Ratio = 1.7 (95% confidence interval 0.5-5.3)). The most frequently reported injuries were those to the acromio-clavicular joint; dislocations resulted in the greatest amount of missed play. Using video analysis, 47 of the 100 shoulder injury events were successfully identified and analyzed. The main mechanisms of shoulder injury were contact with the ground with the shoulder/arm in horizontal adduction, flexion, and internal rotation; and impact to the lateral aspect of the shoulder with the elbow flexed and arm at the side. Conclusions: Direct impact to the shoulder, either through player-to-player contact or contact with the ground, is the main cause of shoulder injury. Methods to reduce injury risk, such as shoulder pads and tackle skills, require consideration. © 2014 Sports Medicine Australia.