Introduction:
Cricket bowling has traditionally required a rigid arm, with no elbow straightening allowed. However, research shows that maintaining a completely rigid arm is impractical, leading to rule changes. The current regulation mandates that the elbow extension angle must not increase by more than 15 degrees. This study aims to determine whether this rule is upheld across various bowlers and styles and to explore if alternative kinematic measures can better distinguish between legal and suspect actions.
Methods:
Sixteen male fast bowlers from NSW grade clubs were analysed using a Cortex 2.0 motion analysis system (200 Hz). The study measured changes in elbow angular kinematics, defined as the angle between the upper arm and forearm relative to the flexion-extension axis of a joint coordinate system.
Results and Discussion:
The mean elbow extension angle was 14.0 ± 8.4°. Surprisingly, six bowlers exceeded the 15° legal limit, even though only one was considered suspect a priori. This may be due to a perspective error of elbow flexion during the critical period when the arm is horizontal and behind the bowler’s body. The mean change in elbow flexion-extension angular velocity at release was -123.5 ± 316.9 °/s, showing significant variability, an indicator of the diversity of elbow mechanics in bowling. This diversity suggests that a one-size-fits-all model for elbow movement during bowling is not valid. Coaches and regulatory bodies need to consider this variability when developing training programs and rules.
Conclusions:
More bowlers exceed the legal limit than visually assessed. Rigorous biomechanical screening programs are essential to ensure fairness for batters and compliant bowlers. High elbow angular velocities make it difficult to detect throw-like actions visually. Educating coaches on perspective errors is crucial. Analysing elbow extension angular velocity at ball release provides a more effective differentiation. Cricket authorities must address bowling legality issues for the game's future equity.