A THREE DIMENSIONAL CINEMATOGRAPHICAL INVESTIGATION OF THE TECHNIQUES OF INTERNATIONAL AND ENGLISH COUNTY CRICKET FAST BOWLERS

Abstract

The aim of the study was to investigate the techniques of elite fast and fast-medium cricket bowlers. Three dimensional cine techniques (2WHz) were used to obtain images of 17 First Class cricketers (12 Internationals, 5 County players) at English Test and County matches, and prearranged net sessions. The bowlers were classified in terms of their ability to attain a Side-On position in the delivery phase (back foot contact to front foot contact) of bowling. Film sequences were digitised at 100Hz using a TDS HR48 digitising tablet interfaced to an Acorn Archimedes 440 microcomputer. Reconstruction of the two sets of two dimensional Image coordinates was performed using the direct linear transformation algorithm with allowance for lens distortion. # The bowlers analysed were categorised into two groups: Side-On (Shoulder Angle <2w0 at back or front foot contact compared to the plane of the wicket, and Front-On ( Shoulder Angle >2009. The criteria for these groups was set by previous research (Foster et al., 1989) and by consideration by the project staff of the National Cricket Association Sport Science Support Programme. Results showed that in addition to the differences that occur for the angles of the back foot, the hips and the shoulders In the attainment of a Side-On position, there were also differences in the ball release speeds (Side411 group = 37.86+1.12m.s", Front-On = 34.9' 9.91m.s-I), and front knee angles at front foot contact (Side-On= 165.9f 7.3', Front-On= 172.9f 3.459 and ball release (Side-On = 150.62 23.6', Front-On = 151.3t18.74. The results showed that both groups of bowlers tended to flex the knee on impact and failed to subsequently extend the knee at ball release. It is apparent from the data that closer scrutiny of the results of Individual bowlers may further aid the Identification of the positive and deleterious effects of Side-On and Front-On bowling.