Very little research has been undertaken regarding an optimal run-up distance, as the main function is to allow the bowler to reach the required run-up speed for their specific style of bowling (Mason et al. 1989). Consequently, run-up distances vary from bowler to bowler. The run-up has been defined as the distance travelled from when the bowler passes their marker and begins to jog, to the pre-delivery stride (Bartlett et al. 1996). Davis and Blanksby (1976) report that regardless of the style of bowling a “14-pace” run-up will be sufficient to release the ball at optimal velocity. However, the theory that faster run-up speed is not directly proportional to a faster ball release speed is emphasised throughout other studies, as effective technique is a key issue (Elliott and Foster, 1984). Davis and Blanksby (1976) produced conflicting findings; stating that of 17 fast bowlers tested, the 6 fastest bowlers reported mean approach distances 2.14m longer than the 6 slowest bowlers, although as no set distances were reported it is difficult to compare with other findings. However, as highlighted above a generic optimal run-up distance is not achievable due to the physical and technical variations seen in fast bowlers, thus run-up speed may be a more indicative measure of how pre- delivery characteristics may affect fast bowling.
2.4.2.2 Run-up Speed
Although the importance of correct run-up distance is emphasised, studies have placed more emphasis on analysing run-up speeds (Elliott et al. 1992; Elliott et al. 1993; Burnett et al. 1995). Run-up speeds have been shown to vary depending on which bowling action is being performed. A front-on action typically displays higher run up speeds than a side-on action, as a side-on action requires more time during the pre- delivery stride to re-orientate the shoulders and hips (Elliott and Foster, 1984; Bartlett et al., 1996). Consequently, the impact of run-up speed may provide some insight into which bowling technique may allow higher ball release speeds. Run-up speeds have been well documented and can be seen displayed in table 2.4.2. However, most studies have only taken measurements at the beginning of the pre-delivery stride (Elliott et al. 1986; Elliott et al., 1992). From this data we cannot make any assumptions regarding
the effect of run-up distance on run-up speed. Mason and colleagues (1989) suggests that peak running velocity is reached approximately 8-16m before the crease, as bowlers typically slow down in preparation for delivery. Consequently, it may be argued that a shorter run-up may be advantageous if a constant running velocity was to be maintained, conserving the bowlers’ energy, whilst still reaching the same run-up speed at the pre-delivery stride.
Research has attempted to quantify the effectiveness of run-up distance and speed via correlation with a performance measure (Worthington et al. 2013), typically ball release speed. However, the degree to which the speed of run-up contributes to ball release speed may vary between bowlers, due to the wide variability in bowling actions (Elliott and Foster, 1984). As a result, correlating ball release speed with run-up speed becomes difficult. Studies have attempted to calculate percentage contribution of run-up speed using the following calculation seen in equation 2.4.1 (Davis and Blanksby, 1976; Elliott et al. 1986):
Equation 2.4.1. Calculation for percentage contribution of run-up speed to ball release speed. However, this equation assumes that no other variables are involved, which as stated above, is not the case. Consequently, this equation may be regarded as too simplistic. Studies have also aimed to establish a relationship between run-up speed and ball release speed via manipulation of run-up speed (Brees, 1989). Brees (1989) concluded that there was a positive correlation between run-up speed and ball release speed but the correlation between run-up speed and accuracy was negative. These changes have been attributed to the changes in bowling kinematics observed (Brees, 1989). An increase in run-up speed was seen to be related to decreased trunk lateral flexion and flexion, whilst an increase in knee flexion was observed. However, these kinematic changes may not be representative of the kinematics displayed during match situations, as the testing protocol required trained bowlers to perform a bowling action that they are not accustomed to, such as an excessively slow or fast run-up. Although it has been acknowledged that run-up speed is conceptually likely to have some contribution to ball release speed; due to the lack of substantiated evidence produced in the current
literature, the relationship between run-up speed and the remaining bowling action is unclear.
2.4.2.3 Pre-delivery Stride
The pre-delivery stride has been defined by the Marylebone Cricket Club as the stride that separates the run up from the delivery stride. It consists of a jump off of the leading leg, allowing enough time to orientate the body for the rear-foot impact in the delivery stride (M.C.C., 1976). Few studies have reported the impact of the pre-delivery stride on the kinematics during the delivery stride; however, it may be assumed that the length of the pre-delivery stride will vary depending on the bowling action being performed. A side-on bowler may need more time to rotate 180º for back-foot impact (BFI) compared to a front-on bowler who does not need to rotate to enter the delivery stride (Bartlett et al. 1996). Davis and Blanksby (1976) reported that faster bowlers’ delivery stride was 22% longer than the previous run-up stride. Slower bowlers were reported to have only increased stride length by 5% in the pre-delivery stride. This may be explained by the increased need to decelerate, to facilitate an effective bowling action (Davis and Blanksby, 1976).