Description:
Cricket was the first sport to publish recommended methods for injury surveillance in 2005. Since then, there have been changes to the nature of both cricket and injury surveillance. Researchers representing the major cricket playing nations met to propose changes to the previous recommendations, with an agreed voting block of 14. It was decided that 10 of 14 votes (70%) were required to add a new definition element and 11 of 14 (80%) were required to amend a previous definition. In addition to the previously agreed 'Match time-loss' injury, definitions of 'General time-loss', 'Medical presentation', 'Player-reported' and 'Imaging-abnormality' injuries are now provided. Further, new injury incidence units of match injuries per 1000 player days, and annual injuries per 100 players per year are recommended. There was a shift towards recommending a greater number of possible definitions, due to differing contexts and foci of cricket research (eg, professional vs amateur; injury surveillance systems vs specific injury category studies). It is recommended that researchers use and report as many of the definitions as possible to assist both comparisons between studies within cricket and with those from other sports.
Description:
Human arm movements need 'online' corrections due to noise in perception and action. A Step-Perturbation paradigm explored online corrections in control children and children with DCD aged between 7 and 13 years. Control children found the task straightforward: a distracter had no effect and they managed to stop relatively quickly. Children with DCD found the task difficult and the apparatus was modified accordingly (decreased postural and force production demands). The distracter affected some children with DCD and some found it difficult to stop. All of the DCD population showed poorer performance in both the perturbation and non-perturbation condition. Nevertheless, there was no interaction between group and condition. Thus, this study found no evidence for specific deficits in online correction mechanisms in DCD. We suggest that: (i) fundamental problems in generating basic movements can account for the documented difficulties in correcting on-going movements, and (ii) such fundamental difficulties make it very difficult to pinpoint specific mechanism deficits.
Description:
Given the escalating drought conditions in Australia, synthetic surfaces have recently been explored as a viable surface option for community-level Australian football-cricket ovals. The vast majority of Australian football ovals are transformed into cricket pitches during the football off-season and hence the characteristics of both sports had to be duly considered in the development of standards that could be tested in a laboratory setting, for a synthetic turf surface. This paper describes the data collection and test methods undertaken in the development of the standards for synthetic surface use in Australian football and cricket. The paper also discusses the issues and challenges encountered during the development of standards for multi-sport synthetic surfaces to ensure player safety while maintaining the performance characteristics of both sports. Surface property and ball interaction tests were undertaken on natural playing surfaces, both in situ and in the laboratory to determine the properties of the current playing surface for each sport. This paper highlights the importance of careful consideration of the characteristics of both games and the use of equipment from both sports in the testing methods. The standards described in this paper have now been accepted by the Australian Football League and Cricket Australia and the product approval process and use of synthetic surfaces for Australian football and cricket is imminent.
Description:
There is a strong political consensus in a number of countries that occupational safety and health regulation is stifling industrial innovation and development and is feeding a culture of damaging risk aversion and petty bureaucracy. In a number of countries this has led to proposals to repeal regulations and reduce the regulatory burden. The authors were commissioned to prepare a discussion paper on this issue by the Mercatus Center of George Mason University in Arlington, Virginia, aimed particularly at an American audience. This paper is based on that report (Hale et al., 2011). The paper is based on previous work of the first two authors, developing a framework of occupational safety rule management at the workplace level (Hale and Borys, 2012a,b). Based on a literature study, this paper analyses the similarities and differences between rules at the workplace level and the development, use and enforcement of regulations at the national level to influence and control organisational behavior. It traces the forces encouraging the growth of regulatory detail and hence the bureaucratic burden of compliance and the options open to reduce that burden without loosening control so much that the level of safety declines. The analysis uses the hierarchy of rules from goals, through process (risk management) rules to detailed action rules as framework for predicting the level of ownership and responsibility felt by the regulated.
Description:
This study reports the time to sustain a mild traumatic brain injury (mTBI) among a cohort of community rugby union players. Demographic and player characteristics were collected and players followed up for between one and three playing seasons. 7% of the cohort sustained an mTBI within 10 h of game time, increasing twofold to 14% within 20 h. The mean time to first mTBI was 8 h with an SD of 6.2 (median 6.8 h; IQR: 2.9–11.7 h). Players reporting a recent history of concussion were 20% more likely to sustain an mTBI after 20 h of game time compared with those with no recent history of concussion. Players were likely to sustain an mTBI in shorter time if they trained for <3 h/week (HR=1.48, p=0.03) or had a body mass index <27 (HR=1.77, p=0.007). The findings highlight modifiable characteristics to reduce the likelihood of shortened time to mTBI.
Description:
The effect of advance ('precue') information on short aiming movements was explored in adults, high school children, and primary school children with and without developmental coordination disorder (n=10, 14, 16, 10, respectively). Reaction times in the DCD group were longer than in the other groups and were more influenced by the extent to which the precue constrained the possible action space. In contrast, reaction time did not alter as a function of precue condition in adults. Children with DCD showed greater inaccuracy of response (despite the increased RT). We suggest that the different precue effects reflect differences in the relative benefits of priming an action prior to definitive information about the movement goal. The benefits are an interacting function of the task and the skill level of the individual. Our experiment shows that children with DCD gain a benefit from advance preparation in simple aiming movements, highlighting their low skill levels. This result suggests that goal-directed RTs may have diagnostic potential within the clinic.
Description:
Background: There is a risk of concussion when playing rugby union. Appropriate management of concussion includes compliance with the return-to-play regulations of the sports body for reducing the likelihood of premature return-to-play by injured players. Purpose: To describe the proportion of rugby union players who comply with the sports body's regulations on returning to play postconcussion. Study design: Prospective cohort study. Methods: 1958 community rugby union players (aged 15–48 years) in Sydney (Australia) were recruited from schoolboy, grade and suburban competitions and followed over ≥1 playing seasons. Club doctors/physiotherapists/coaches or trained injury recorders who attended the game reported players who sustained a concussion. Concussed players were followed up over a 3-month period and the dates when they returned to play (including either a game or training session) were recorded, as well as any return-to-play advice they received. Results: 187 players sustained ≥1 concussion throughout the follow-up. The median number of days before players returned to play (competition game play or training) following concussion was 3 (range 1–84). Most players (78%) did not receive return-to-play advice postconcussion, and of those who received correct advice, all failed to comply with the 3-week stand-down regulation. Conclusions: The paucity of return-to-play advice received by community rugby union players postconcussion and the high level of non-compliance with return-to-play regulations highlight the need for better dissemination and implementation of the return-to-play regulations and improved understanding of the underlying causes of why players do not adhere to return-to-play practices.
Description:
OBJECTIVE: To deduce whether similar or distinct populations of vestibular afferents are activated by acoustic and galvanic vestibular stimulation by comparing the effectiveness of 'matched' stimuli in eliciting vestibulospinal reflexes. METHODS: Twelve subjects (5 men, 7 women) underwent individual 'matching' of 2 ms tone burst and galvanic stimuli, using vestibulocollic reflexes so that corrected reflex amplitudes to tone burst and galvanic stimuli were within 10% of each other. These same intensities were then administered using 20 ms durations to determine whether they were equally effective in evoking vestibulospinal responses. RESULTS: Corrected reflex amplitudes for vestibulocollic responses to tone burst and galvanic stimulation were not significantly different for the right (P=0.45) or left (P=0.68) sides. All subjects had vestibulospinal responses to galvanic stimulation (average intensity 4.0 mA for both sides). The short latency (SL) and medium latency (ML) components of the vestibulospinal reflexes were larger after galvanic compared to tone burst stimulation in 11 of 12 subjects (P<0.01). CONCLUSIONS: Despite evoking equal-sized vestibulocollic reflexes, there was a clear dissociation between the magnitude of tone burst and galvanic-induced vestibulospinal reflexes. Galvanic stimulation evoked SL and ML reflexes in all subjects. Tone burst stimuli evoked only small SL reflexes and, in most cases, no ML reflexes. Acoustically-evoked vestibulocollic reflexes are likely to be due to saccular excitation. The limited effectiveness of longer tone burst stimuli to evoke ML vestibulospinal reflexes suggests that saccular afferents have, at most, only a minor role in the production of these reflexes. We conclude that galvanic stimulation is more effective in eliciting vestibulospinal reflexes than tone burst stimulation, and that the two methods activate different populations of vestibular afferents.
Description:
The purpose of this paper is to summarise the methodology for the 5th International Consensus Conference on Concussion in Sport. The 18 months of preparation included engagement of a scientific committee, an expert panel of 33 individuals in the field of concussion and a modified Delphi technique to determine the primary questions to be answered. The methodology also involved the writing of 12 systematic reviews to inform the consensus conference and submission and review of scientific abstracts. The meeting itself followed a 2-day open format, a 1-day closed expert panel meeting and two additional half day meetings to develop the Concussion Recognition Tool 5 (Pocket CRT5), Sport Concussion Assessment Tool 5 (SCAT5) and Child SCAT5.
Description:
Aim To critically review the evidence to determine the efficacy and effectiveness of protective equipment, rule changes, neck strength and legislation in reducing sport concussion risk. Methods Electronic databases, grey literature and bibliographies were used to search the evidence using Medical Subject Headings and text words. Inclusion/ exclusion criteria were used to select articles for the clinical equipment studies. The quality of evidence was assessed using epidemiological criteria regarding internal/external validity (eg, strength of design, sample size/power, bias and confounding). Results No new valid, conclusive evidence was provided to suggest the use of headgear in rugby, or mouth guards in American football, significantly reduced players' risk of concussion. No evidence was provided to suggest an association between neck strength increases and concussion risk reduction. There was evidence in ice hockey to suggest fair-play rules and eliminating body checking among 11-years-olds to 12-years-olds were effective injury prevention strategies. Evidence is lacking on the effects of legislation on concussion prevention. Equipment self-selection bias was a common limitation, as was the lack of measurement and control for potential confounding variables. Lastly, helmets need to be able to protect from impacts resulting in a head change in velocities of up to 10 and 7 m/s in professional American and Australian football, respectively, as well as reduce head resultant linear and angular acceleration to below 50 g and 1500 rad/s2, respectively, to optimise their effectiveness. Conclusions A multifactorial approach is needed for concussion prevention. Future well-designed and sportspecific prospective analytical studies of sufficient power are warranted.