Discussion

The aim of this study was to analyse the rates of injury and illness among multiple teams competing at the CWC 2011. The reasons were twofold, the first being to gain insight into the most important injury problems occurring during tournaments, and secondly, to pilot the logistics of conducting such a programme so that comprehensive injury surveillance of all teams may be instituted during all fixtures of the ICC Future Tours calendar and ICC Events.

That the medical staff of the five participating teams recorded 120 new injuries suggests that compliance with the request to record all problems presenting for medical attention was high. Similarly, the completeness of the data attests to the efficacy of using a networked electronic data collection system as opposed to most other similar programmes in other sports that have relied upon paper based data collection,3–6 ,12 ,15 which although effective, are likely to require significantly more collection and processing human resource. As only one of the participating teams, South Africa,11 has previously published any injury data, this study is perhaps an important first step in broadening and deepening the general knowledge of injury rates and risk factors previously only report by a few individual nations.9 ,13 ,16

Although an average of 1.6 new injuries per player across five teams seems a relatively high number for a tournament of this duration, it is worth noting that only 23 (19%) were ‘time-loss’, that is, they resulted in players being considered unavailable for selection. This study is the first to record ‘non-time-loss’ injuries in cricket and their seemingly high incidence indicates that cricketers, particularly fast bowlers, continue to play and train despite requiring medical attention, sometimes for multiple injuries. Future research should investigate the potential effects of these somewhat ‘occult’ injuries on performance, and any progression to more serious injury, particularly of lower back and knee problems that also rank highly within time-loss injuries.

Time-loss injury incidence was even across batters and bowlers (pace and slow), with wicket-keepers having a very low injury incidence and prevalence, as shown in other work.17 The bowling match injury incidence in this study was slightly higher than reported for Australian domestic one-day cricket (2.7 vs 2.2/1000 overs) and while it is not possible to draw firm inferences from one tournament, a higher intensity of cricket and players aggravating injuries carried into games may be contributing factors.

It appears that as previously recognised thigh (hamstring, quadricep and adductor) muscle strain injuries13 seem to commonly occur in the limited overs format of the game. However, in this study relatively low prevalence figures for this body area indicate ‘time-loss’ for these types of injuries was relatively short. It is known that recurrence rates for thigh strain injuries are high18 ,19 and therefore recognised risk factors such as muscle strength imbalance20 should be thoroughly addressed during rehabilitation and prevention programmes.

Not unexpectedly for a tournament conducted in the subcontinent, medical illness, particularly gastrointestinal problems, was common. Reassuringly, the prevalence rates indicate bouts were mostly short lived and this is probably testament to the aggressive treatment practices now undertaken by most travelling sports teams who are acutely aware of this problem.21 Nevertheless, the high incidence suggests that precautions such as hand washing, eating only piping hot well prepared food, drinking bottled water and isolating sick team members remain indicated.

Unsurprising is that along with acute strains and sprains (particularly thigh and ankle respectively), injuries due to being hit by the ball made up the bulk of ‘time-loss’ incidences while the ‘non-time-loss’ problems were predominantly attributed to cumulative micro-trauma. While the ICC recognises that helmet and glove design should be improved in the attempt to reduce the incidence and severity of impact injury to batters, there is an increasing concern that fielders are at risk from balls being hit ever harder in their direction.

Orchard and et al12 expressed concern that injury prevalence for their cohort of Australian domestic cricketers had increased to over 10% during the last few years. The tournament and match injury prevalence rates for the CWC were approximately half of that at around 5%. The lower prevalence rate seen during the CWC may be due to a number of factors and it is tentatively speculated that these could include; players and teams risking playing on despite injury due to the importance of the tournament, greater preparation and recovery time between matches due to the relatively spread out nature of the fixtures, and the limited bowling workload of a maximum of 10 overs per bowler per match for this format of cricket. Considerably higher over rates and consecutive days of bowling are undertaken during 4-day or 5-day cricket matches.

The time-loss match injury incidence of 71/10 000 player-hours is comparable to the long-term average for Australian domestic and international 1-day cricket reported by Orchard et al12 of approximately 50/10 000 player-hours. In this study a further 244 non-time-loss injuries per 10 000 player-hours were found to have been sustained during matches. As the incidence of non-time-loss injury data has never previously been collected it is difficult to comment on whether this is a high number or not. However, as many players, particularly older players, are clearly playing through injuries sustained during matches further study into the influence of these type of injuries on player performance and rates of progression to time-loss injury are warranted.

Injury suffered during the delivery stride or follow through of bowling was the activity that accounted for by far the greatest lost playing time, re-enforcing that this cricketing activity has the highest risk of severe injury.17 There are very few fast bowling injury prevention intervention studies and they have focused on technique modification in small groups of young fast bowlers.22 Recent work has identified that due to complex and highly trained movement patterns associated with the mature fast bowling action, modifying what are thought to be the most injurious technique characteristics is likely to be extremely difficult.23 There are also a limited number of studies identifying a link between injury-risk and bowling workload24 ,25 and although this information has been incorporated into workload directives and guidelines in Australia and the UK, the effectiveness has not been assessed. While it is accepted that bowling, in particular fast-bowling, has inherent injury risk, data from this study highlights the need for further research, coach and player education and management of potentially modifiable risk factors. In order for bowlers to have the best chance of minimising their unavailability for training and matches factors such as workload, footwear, training surfaces, bowler conditioning, nutrition, hydration and recovery practices need to be addressed.

A limitation of the study is that only ‘Tournament’ incidence and prevalence figures could be calculated, as injuries that prevented players being available for tournament selection could not be considered. Had they been, overall injury rates for the participating teams are likely to have been higher. Further, as the data is from only 5 of the 14 teams over one tournament it was not possible to measure aspects such as recurrence of injury and for these reasons generalisability of this preliminary study is limited. However, only one of these five teams11 has previously reported injury data and the number of injuries reported indicates that the medical staffs were diligent in their recording. The analysis also applies to only one type of cricket, 50-over 1-day Internationals, and other formats of the game also need to be tracked, ideally over the complete ICC Future Tours Programme.

With the rising prominence of formats such as T20 and because non-time-loss injuries are not included, it is recommended that the 2005 guidelines for injury surveillance in international cricket be revised. Suggested amendments to the injury rate units that might better reflect the modern cricket calendar include expressing match injury incidence per 1000 days of play, rather than per 10 000 h of play as they are now.13 Also, in line with the terminology used in international rugby injury surveillance26 the cricket injury definitions should be expanded to separately include ‘non-time-loss’ and ‘time-loss’ injuries, not simply the current ‘match time-loss injuries’. Suggested definitions are:

• Non-time-loss injury: Any injury or illness that requires medical assessment or treatment but would not cause the player to be considered unavailable for major match selection, regardless of whether a major match is scheduled within the duration of the injury.

• Time-loss injury: Any injury or illness whereby a player would be considered unavailable for major match selection for at least a 24 h period, regardless of whether there is a match scheduled within that period or not.

Within the injury definition, medical staff would need to assume that a major match is scheduled on every day of the year and based on that, make a judgement on whether the player would be considered unavailable on any given day. The number of days of time-loss is calculated from the date they would first be considered unavailable for major match selection, to the date they would be first considered available for major match selection. For all injuries, the duration of the injury would be calculated from the date of first symptoms, to the date where no further medical intervention is considered to be required, that is, the date of injury resolution. These updated definitions would help identify injuries that limit cricket participation without reliance on cricket match scheduling. Match schedules would of course still need to be considered when determining ‘match injury incidence and prevalence’.