The biomechanics of the elbow in cricket bowling

Objective: Most bowlers in cricket attempt to maintain a straight arm during the latter phase of ball delivery. Recently, however, concern has been expressed about several bowlers using a bent arm delivery. This article will compare data from traditional straight arm technique to published analyses of 'bent arm bowling', and examine the potential advantages and disadvantages relative to ball speed, injury potential and elbow joint kinetics. Data sources: Refereed journal articles, a web page and conference proceedings. Study section: Four articles discussed the kinematics of a bent arm delivery in cricket, and three papers reported data on the kinematics and/or kinetics of the bowling arm. Previously unpublished data for the kinetics of the elbow in bowling are presented and compared to two articles reporting values for varus torques in throwing. Data extraction: With the limited number of papers available, no abstraction of data was performed. Data synthesis: Varus/valgus torques on the elbow in straight arm bowling are small compared to throwing activities. However, the use of a bent arm introduces the potential to make use of upper arm internal rotation to substantially increase ball release speed. This in turn increases the potential varus stress on the elbow. Conclusions: The traditional bowling technique in cricket causes low levels of varus and flexion torques at the elbow to provide joint stabilisation. The use of a legal bent arm action introduces the opportunity to increase ball speed substantially, with a concomitant cost of large increases in varus torques at the elbow. As these torques are generated primarily by ligament and capsular restraints, it increases the potential for elbow injury and it may be necessary to consider additional limitations to bowling frequency to prevent elbow damage.