The art of cricket bowling is complex and arduous owing to the run-up and ball release time energy requirement to achieve speed and variations. Therefore, human bowlers cannot bowl for extended periods and numerous me...The art of cricket bowling is complex and arduous owing to the run-up and ball release time energy requirement to achieve speed and variations. Therefore, human bowlers cannot bowl for extended periods and numerous mechanical bowling machines have been built to help batsmen improve their skills during practice sessions. However, most of these existing machines are designed for spherical balls ignoring the distinguishing physical feature of a cricket ball: the raised equatorial seam, which makes it less of a sphere. The bowlers are known to often benefit from this seam in their pursuit to taking the batsmen's wicket by imparting swing, spin and bounce variations along-with other bowling variables. This lack of the seam consideration creates a void between human and mechanical bowling. In this work, we present design and development of an automatic bowling machine termed as ROBOWLER to make mechanical bowling more realistic. This machine ensures ball seam position as well as fulfills other constraints. Ball pitching and seam position accuracy results underscore the suitability of this design to enhance the capabilities of mechanical bowling.展开更多
Background:Injuries to the hamstring are relatively common in professional cricketers(as they are in many team sports) and have increased in incidence in the "T20 era"(introduction of 20-over matches) of cri...Background:Injuries to the hamstring are relatively common in professional cricketers(as they are in many team sports) and have increased in incidence in the "T20 era"(introduction of 20-over matches) of cricket since 2006.Methods:This study analyzed incidence of hamstring injury in the various elite male match types over a 20-year period(1995–1996 to 2014–2015seasons).Risk factors for hamstring strain were assessed using a multivariate logistic regression analysis technique.Results:There were 276 match time-loss hamstring injuries recorded over a 20-year period at the Australian state or national player level,of which170 occurred in one of 40,145 player match sets.The overall rate of match onset rate was 22.5 hamstring injuries per 1000 team days.Fast bowling onset injuries were the highest subcategory at a rate of 10.9 injuries per 1000 team days,although batting onset injuries were particularly common in 50-over(one day) international matches.Significant risk factors in logistic regression analysis,in addition to hamstring injury history,were being a fast bowler relative risk(RR) 2.5(95% confidence interval(CI):1.3–4.5) and playing a match in Australia RR 2.3(95%CI:1.3–3.9).Conclusion:Fast bowlers suffer more hamstring injuries than other playing roles in cricket,particularly in First Class(multi-day) cricket.Batsmen are more likely to get injured in 50-over(one day) cricket.Playing in Australia(compared to overseas venues) leads to increased risk of hamstring injury.展开更多
文摘The art of cricket bowling is complex and arduous owing to the run-up and ball release time energy requirement to achieve speed and variations. Therefore, human bowlers cannot bowl for extended periods and numerous mechanical bowling machines have been built to help batsmen improve their skills during practice sessions. However, most of these existing machines are designed for spherical balls ignoring the distinguishing physical feature of a cricket ball: the raised equatorial seam, which makes it less of a sphere. The bowlers are known to often benefit from this seam in their pursuit to taking the batsmen's wicket by imparting swing, spin and bounce variations along-with other bowling variables. This lack of the seam consideration creates a void between human and mechanical bowling. In this work, we present design and development of an automatic bowling machine termed as ROBOWLER to make mechanical bowling more realistic. This machine ensures ball seam position as well as fulfills other constraints. Ball pitching and seam position accuracy results underscore the suitability of this design to enhance the capabilities of mechanical bowling.
文摘Background:Injuries to the hamstring are relatively common in professional cricketers(as they are in many team sports) and have increased in incidence in the "T20 era"(introduction of 20-over matches) of cricket since 2006.Methods:This study analyzed incidence of hamstring injury in the various elite male match types over a 20-year period(1995–1996 to 2014–2015seasons).Risk factors for hamstring strain were assessed using a multivariate logistic regression analysis technique.Results:There were 276 match time-loss hamstring injuries recorded over a 20-year period at the Australian state or national player level,of which170 occurred in one of 40,145 player match sets.The overall rate of match onset rate was 22.5 hamstring injuries per 1000 team days.Fast bowling onset injuries were the highest subcategory at a rate of 10.9 injuries per 1000 team days,although batting onset injuries were particularly common in 50-over(one day) international matches.Significant risk factors in logistic regression analysis,in addition to hamstring injury history,were being a fast bowler relative risk(RR) 2.5(95% confidence interval(CI):1.3–4.5) and playing a match in Australia RR 2.3(95%CI:1.3–3.9).Conclusion:Fast bowlers suffer more hamstring injuries than other playing roles in cricket,particularly in First Class(multi-day) cricket.Batsmen are more likely to get injured in 50-over(one day) cricket.Playing in Australia(compared to overseas venues) leads to increased risk of hamstring injury.
