Changes to injury profile (and recommended cricket injury definitions) based on the increased frequency of Twenty20 cricket matches.

This study analyzes injuries occurring prospectively in Australian men's cricket at the state and national levels over 11 seasons (concluding in season 2008-09). In the last four of these seasons, there was more cricket played, with most of the growth being a new form of the game - Twenty20 cricket. Since the introduction of a regular Twenty20 program, injury incidence rates in each form of cricket have been fairly steady. Because of the short match duration, Twenty20 cricket exhibits a high match injury incidence, expressed as injuries per 10,000 hours of play. Expressed as injuries per days of play, Twenty20 cricket injury rates compare more favorably to other forms of cricket. Domestic level Twenty20 cricket resulted in 145 injuries per 1000 days of play (compared to 219 injuries per 1000 days of domestic one day cricket, and 112 injuries per 1000 days of play in first class domestic cricket). It is therefore recommended that match injury incidence measures be expressed in units of injuries per 1000 days of play. Given the high numbers of injuries which are of gradual onset, seasonal injury incidence rates (which typically range from 15-20 injuries per team per defined 'season') are probably a superior incidence measure. Thigh and hamstring strains have become clearly the most common injury in the past two years (greater than four injuries per team per season), perhaps associated with the increased amount of Twenty20 cricket. Injury prevalence rates have risen in conjunction with an increase in the density of the cricket calendar. Annual injury prevalence rates (average proportion of players missing through injury) have exceeded 10% in the last three years, with the injury prevalence rates for fast bowlers exceeding 18%. As the amount of scheduled cricket is unlikely to be reduced in future years, teams may need to develop a squad rotation for fast bowlers, similar to pitching staff in baseball, to reduce the injury rates for fast bowlers. Consideration should be given to rule changes which may reduce the impact of injury. In particular, allowing the 12th man to play as a full substitute in first class cricket (and therefore take some of the bowling workload in the second innings) would probably reduce bowling injury prevalence in cricket.