3,012 research outputs found

    Optical Flameout Detector

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    A device has been developed which monitors the presence of a flame within a combustion chamber. The optical flameout detection system responds to gross changes in combustor light intensity which is monitored in two spectral bands. A photomultiplier tube makes optical measurements in the ultraviolet portion of the spectrum and a silicon photodiode covers the visible region. The detectors, located outside the combustion chamber, receive the light energy radiated from the combustion process through fiber optic probes designed to operate in a high pressure environment. The optical fibers are aimed diagonally through the center of the injector at the combustion chamber wall downstream of the injector. The probe observes events occurring within a narrow conical-shaped field of view so that the system can quickly detect longitudinal movement of the flame front away from the injector. If a change in intensity of the flame is detected, the fuel supply to the combustion chamber is shut off limiting the amount of unburned fuel in the combustion chamber which could reignite

    Training load and injury risk in elite Rugby Union:The largest investigation to date

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    AbstractTraining load monitoring has grown in recent years with the acute:chronic workload ratio (ACWR) widely used to aggregate data to inform decision-making on injury risk. Several methods have been described to calculate the ACWR and numerous methodological issues have been raised. Therefore, this study examined the relationship between the ACWR and injury in a sample of 696 players from 13 professional rugby clubs over two seasons for 1718 injuries of all types and a further analysis of 383 soft tissue injuries specifically. Of the 192 comparisons undertaken for both injury groups, 40% (all injury) and 31% (soft tissue injury) were significant. Furthermore, there appeared to be no calculation method that consistently demonstrated a relationship with injury. Some calculation methods supported previous work for a “sweet spot” in injury risk, while a substantial number of methods displayed no such relationship. This study is the largest to date to have investigated the relationship between the ACWR and injury risk and demonstrates that there appears to be no consistent association between the two. This suggests that alternative methods of training load aggregation may provide more useful information, but these should be considered in the wider context of other established risk factors.</jats:p

    Optical flameout detector

    Get PDF
    A device has been developed which monitors the presence of a flame within a combustion chamber. The optical flameout detection system responds to gross changes in combustor light intensity, which is monitored in two spectral bands. A photomultiplier tube makes optical measurements in the ultraviolet portion of the spectrum, and a silicon photodiode covers the visible region. The detectors, located outside the combustion chamber, receive the light energy radiated from the combustion process through fiber optic probes designed to operate in a high pressure environment. The optical fibers are aimed diagonally through the center of the injector at the combustion chamber wall downstream of the injector. The probes observe events occurring within a narrow conical-shaped field of view so that the system can quickly detect longitudinal movement of the flame front away from the injector. If a change in intensity of the flame is detected, the fuel supply to the combustion chamber is shut off, limiting the amount of unburned fuel in the combustion chamber which could reignite

    Caught on camera:a video assessment of suspected concussion and other injury events in women's rugby union

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    Objectives: The objective of this study was to identify and report the incidence and mechanisms of suspected injury and concussion in women's rugby union. Design: A cross-sectional video analysis study. Methods: Using video analysis of non-professional, single-angle footage, cases of suspected injury and concussion were identified and reported, based on content validation and consensus by eight rugby-specific researchers, therapists, and sport medicine physicians. Results: There were 225 suspected injuries recorded in 48 games [Suspected injury rate (IR) = 117.5/1000 h (95 % CI;102.6–133.9) or 4.7 suspected injuries per match]. The on-field medical attention IR was 95.0/1000 h (95 % CI;81.7–109.9: 3.8 per game). Suspected concussions accounted for 26 % of injuries (30.8/1000 h: 95 % CI;23.5–39.7: 1.2 per game). The attacking team sustained 64 % of suspected injuries. Permanent removal from play was observed for 29 % of suspected injuries. The most common suspected injury locations were head/neck (28.4 %) and lower extremity (27.6 %). The tackle accounted for 67.1 % of all suspected injuries, with a propensity of 11.2/1000 tackle events (95 % CI;9.5–13.2) or 3.1 tackle-related injuries/game. Of tackle-related injuries, 63.6 % were to the ball carrier while 52.2 % of tackle-related concussions were to the ball carrier. Conclusion: This study adds to the growing body of literature examining women's rugby. The rate of suspected injury is high compared with other studies. It is acknowledged that these are suspected injuries not supported by prospective injury surveillance. The high proportion of suspected injuries that are tackle-related warrants specific attention to identify tackle characteristics associated with injury and concussion.</p

    Training and match load in professional rugby union: Do contextual factors influence the training week?

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    Background: Rugby union demands a multifaceted approach to training, given the multiple physical and technical attributes required to play the sport. Objectives: The aim of this study is to describe the distribution of training throughout the week and investigate how this may be influenced by match-related factors. Methods: Training load data (session Rating of Perceived Exertion [sRPE], total distance and high-speed running [HSR]) were collected from six professional English rugby teams during the 2017/18 season. Five contextual factors were also recorded including: standard of opposition, competition type, result of previous fixture, surface type, and match venue. Results: The day prior to matches demonstrated the lowest training load (101 AU (95% CIs: 0-216 AU) , 1 047 m (95% CIs:1 128-1 686 m) and 59 m (95% CIs: 0-343 m), respectively), while four days prior to the match demonstrated the highest training load (464 AU (95% CIs: 350-578), 2 983 m (95% CIs: 2 704-3 262m) and 234m (95% CIs: 0-477m), respectively). Of the five contextual factors, competition type was the only variable that demonstrated greater than trivial findings, with training before European fixtures the lowest stimulus across the four different competition types. Standard of opposition, previous result, surface type and venue had only trivial effects on training load (effect sizes = -0.13 to 0.15). Conclusion: Future studies should outline the distribution of other training metrics, including contact and collision training. This study provides a multi-club evaluation that demonstrates the variety of loading strategies prior to competitive match play and highlights competition type as the most influential contextual factor impacting the average training load

    Shoulder Check:Investigating Shoulder Injury Rates, Types, Severity, Mechanisms, and Risk Factors in Canadian Youth Ice Hockey

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    Objective: To describe shoulder-related injury rates, types, severity, mechanisms, and risk factors in youth ice hockey players during games and practices. Study Design: Secondary analysis of data from a 5-year prospective cohort study Safeto-Play (2013-2018). Subjects: Overall, 4419 individual players (representing 6585 player-seasons; 3806 males: 613 females) participated. During this period, 118 primary shoulder-related game injuries and 12 practice injuries were reported. Outcome Measures: Injury surveillance data was collected from 2013-2018 (time-loss or medical attention injuries). Descriptive statistics were calculated, and injury rates with 95% CI were estimated using Poisson regression. An exploratory multivariable mixed-effects Poisson regression model (clustering by team and offset by exposure hours) examined risk factors. Results: The shoulder injury rate was 0.70 injuries/1000 game-hours (95% CI 0.371.33) and 0.07 injuries/1000 practice-hours (95% CI 0.04-0.12). Two-thirds of game injuries (n=79, 69%) resulted in &gt;8 days of time-loss, and more than one-third (n=44, 39%) resulted in &gt;28 days of time-loss. An 82% lower rate of shoulder injury was associated with policy prohibiting body checking compared to leagues allowing body checking [IRR=0.18 (95% CI 0.10-0.32)]. A higher shoulder injury rate was seen for those who reported any injury in the last 12-months compared to those with no history [IRR=2.32 (95% CI 1.57-3.41)]. Conclusions: Most shoulder injuries resulted in more than one week of time-loss. Risk factors for shoulder injury included participation in a body checking league and history of injury in the previous 12 months. Further study of prevention strategies specific to the shoulder may merit further consideration in ice hockey

    Shoulder Check:Investigating Shoulder Injury Rates, Types, Severity, Mechanisms, and Risk Factors in Canadian Youth Ice Hockey

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    Objective: To describe shoulder-related injury rates, types, severity, mechanisms, and risk factors in youth ice hockey players during games and practices. Study Design: Secondary analysis of data from a 5-year prospective cohort study Safeto-Play (2013-2018). Subjects: Overall, 4419 individual players (representing 6585 player-seasons; 3806 males: 613 females) participated. During this period, 118 primary shoulder-related game injuries and 12 practice injuries were reported. Outcome Measures: Injury surveillance data was collected from 2013-2018 (time-loss or medical attention injuries). Descriptive statistics were calculated, and injury rates with 95% CI were estimated using Poisson regression. An exploratory multivariable mixed-effects Poisson regression model (clustering by team and offset by exposure hours) examined risk factors. Results: The shoulder injury rate was 0.70 injuries/1000 game-hours (95% CI 0.371.33) and 0.07 injuries/1000 practice-hours (95% CI 0.04-0.12). Two-thirds of game injuries (n=79, 69%) resulted in &gt;8 days of time-loss, and more than one-third (n=44, 39%) resulted in &gt;28 days of time-loss. An 82% lower rate of shoulder injury was associated with policy prohibiting body checking compared to leagues allowing body checking [IRR=0.18 (95% CI 0.10-0.32)]. A higher shoulder injury rate was seen for those who reported any injury in the last 12-months compared to those with no history [IRR=2.32 (95% CI 1.57-3.41)]. Conclusions: Most shoulder injuries resulted in more than one week of time-loss. Risk factors for shoulder injury included participation in a body checking league and history of injury in the previous 12 months. Further study of prevention strategies specific to the shoulder may merit further consideration in ice hockey

    A global survey exploring tackle training knowledge, attitudes and practices of women's rugby union coaches

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    The coaching and performance context in women’s rugby is not well understood, despite growing popularity worldwide. The aim of this study was to describe the knowledge, attitudes and tackle training practices of women’s rugbycoaches in relation to tackle safety and performance. A globally distributed online survey exploring coaches’ knowledge, attitudes and practices towards tackling women’s rugby was completed by 357 coaches (mean age 41 ± 0.6years) from 58 countries. The cross-sectional survey was distributed from March 2023 to June 2023. Survey development was guided by the Health Action Process Approach and informed by coaching experts, research evidence synthesis, and guidelines for international tackle safety programmes. Coaches believed that the risk of tackle injury inwomen’s rugby is high and that proper tackle technique for safety is very important. More than 75% of coacheshad never completed a tackle-specific training course, with only 39% aware of the availability of such courses. Timespent on controlled-contact and full-contact activities varied from 0 to 40+ min per week, averaging 10–20 min forboth types of training. Barriers to the effectiveness of tackle training related to sociocultural factors, coach knowledgegaps, training environments, and player training considerations. Coach education, improved infrastructures, and physical development were ranked the highest priorities for improving tackle safety and performance. These findings informfuture implementation strategies for tackle safety and performance in the context of women’s rugby, highlighting theneed to involve coaches in providing practical solutions, and the role of education and institutional/organisational support in facilitating such improvements

    Patterns of training volume and injury risk in elite rugby union: an analysis of 1.5 million hours of training exposure over eleven seasons

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    Rugby union is a popular team sport that demands high levels of physical fitness and skill. The study aim was to examine trends in training volume and its impact on injury incidence, severity and burden over an 11-season period in English professional rugby. Data were recorded from 2007/08 through 2017/18, capturing 1,501,606 h of training exposure and 3,782 training injuries. Players completed, on average, 6 h 48 minutes of weekly training (95% CI: 6 h 30 mins to 7 h 6 mins): this value remained stable over the 11 seasons. The mean incidence of training-related injuries was 2.6/1000 player-hours (95% CI: 2.4 to 2.8) with a mean severity rising from 17 days in 2007/08 to 37 days in 2017/18 (Change/season = 1.773, P &lt;0.01). Rate of change in severity was dependent on training type, with conditioning (non-gym-based) responsible for the greatest increase (2.4 days/injury/season). As a result of increasing severity, injury burden rose from 51 days absence/1000 player-hours in 2007/08 to 106 days’ absence/1000 player-hours in 2017/18. Despite the low incidence of injury in training compared to match-play, training accounted for 34% of all injuries. Future assessments of training intensity may lead to a greater understanding of the rise in injury severity.</p
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