THE EFFECT OF SELECTED KINEMATICS ON BALL SPEED AND GROUND REACTION FORCES IN FAST BOWLING

Abstract

Lumbar stress fractures and lumbar injury account for the greatest amount of lost playing time in international cricket. Previous research has associated lower back injury with large peak ground reaction forces occurring during the front foot contact phase of the fast bowling action. Selected kinematics of the bowling action of 16 elite male fast bowlers were measured using an 18 camera Vicon Motion Analysis System. Ground reaction forces during front foot contact and ball release speed were recorded; correlations with kinematic factors were identified using Pearson’s correlation coefficient. Ball release speeds were correlated with run-up speed, plant angle and the motion of the front knee during the period of front foot contact. Knee flexion during the first 15 frames of the front foot contact phase was correlated with increased peak vertical force and decreased peak horizontal loading rate. The use of a heel strike technique at the instant of front foot contact was correlated with decreased peak vertical force and loading rates. All correlations observed were moderate in strength, representing the multifactorial nature of the generation of ball speed and ground reaction forces. This study motivates future investigation of the effects of these selected kinematic factors on forces occurring above the knee, and the effect of kinematic factors on the performance of an individual bowler.