MECHANICS OF THE FRONT ARM TECHNIQUE IN CRICKET FAST BOWLING

The purpose of this study was to analyse the kinetics of front arm motion in fast bowling. A sample of 34 fast bowlers was divided into four speed groups. A three-dimensional (3-D) motion analysis system was used to track and analyse the motion trajectory of forty-eight reflective markers placed on each subject to determine the kinematics of segment joint centres. Ground reaction forces were measured with a force platform. These data were used as input to a 3-D 15-segment inverse solution model of the human body, which used a Newton-Lagrange multiplier iterative method to generate the kinetics equations of motion. The calculations show that the front upper arm torques are time-varying cyclic, challenging the coaching notion recommending fast bowlers to pull the front elbow down as fast as possible into the front hip

THE KINEMATIC DIFFERENCES BETWEEN THE LEG-SPIN AND OFFSPIN BOWLING TECHNIQUES IN CRICKET

The purpose of this paper was to determine kinematic differences between the off-spin and leg-spin bowling techniques in cricket. The two techniques are often coached similarly; however, a comparative biomechanical analysis of leg-spin and off-spin bowling has not been performed. A 3D Cortex motion analysis system was used to track 52 markers strategically placed on all the major segments of 23 off-spin and 15 leg-spin bowlers of district level. It was found that the two techniques varied in terms of stride length, but other variables which were not previously differentiated in coaching manuals also displayed significant difference. These results highlight potential technique points that will be of benefit when coaching bowlers of each spin direction

Investigating the biomechanical validity of the V-spine angle technique in cricket fast bowling

The effective utilisation of braking ground reaction forces is considered an essential biomechanical characteristic of fast bowling in cricket. The configuration of the trunk and legs during the delivery stride phase has been hypothesised to increase braking forces, causing the upper body segments to increase their angular momentum and thereby increase ball release speed. This study investigated the relationship between V-spine angle, front shank angle (plant angle) and front knee angle with braking ground reaction forces and ball release speed. Three-dimensional kinematic and kinetic analyses were performed for 17 male pace bowlers (17.2 +/- 1.7 years) of New South Wales grade club level using data from a Cortex 2.0 motion analysis system (200 Hz) and Kistler force plates (1000 Hz). V-spine angle was strongly and significantly correlated with braking ground reaction force (r = -0.691), plant angle (r = -0.806) and front knee angle (r = -0.606). In addition, stepwise multiple linear regression analysis revealed that front shank angle was the strongest predictor of braking ground reaction force. The data suggests that V-spine angle and plant angle may play an important role in generating high braking ground reaction forces in bowling, with the front knee angle possibly playing a supporting role. Coaches may need to consider these findings when assessing the techniques of pace bowlers

Rear leg kinematics and kinetics in cricket fast bowling

The purpose of this study was to analyse the kinematics and kinetics of the rear leg drive in fast bowling, and then investigate whether any of these variables were associated with ball release speed. Eighteen young fast bowlers (17.2 ± 1.7 years) were recruited from the Cricket New South Wales development squad, and their bowling actions were captured by a Cortex 2.0 motion analysis system (200 Hz). Bivariate Pearson's product-movement correlation coefficients were calculated in SPSS (Version 17.0) to assess the relationships between wrist speed (of the bowling hand) and the kinematics and kinetics variables corresponding with rear leg motion. A number of kinematic variables were correlated with bowling wrist speed, most of them during the delivery stride, including mean thigh extension angular velocity (r = 0.606, p = 0.008), thigh adduction angular velocity at back foot contact (r = 0.515, p = 0.029) and maximum change in knee extension angular velocity (r = 0.559, p = 0.016). This study also showed that rear leg drive was not an actively actuated process. Instead, the hip and knee motions in the flexion–extension and adduction–abduction planes were generally subjected to controlled and negligible torque motion-effects