This is a new study of lower-back injuries in young female bowlers
The relationship between the 'mixed' bowling technique and lower-back injuries has been fairly well documented in male cricket players
(eg Foster et al. 1989; Elliott et al. 1992; Elliott et al. 1993 - and see also
Sports Injury Bulletin, issue 6), but there has been no real documented research on whether a similar relationship exists in female cricket bowlers.
The mixed technique, as the name suggests, is a mixture of the side-on and the front-on bowling techniques. The side-on technique is often defined as one where the back foot lands parallel with the popping crease at the start of the delivery stride. The shoulders also point down the wicket, so that the angle between the crease and a line joining the shoulders is approximately 90 deg. In comparison, in the front-on technique the back foot points more towards the direction of intended ball travel, and has a more open-chested position at the start of the delivery stride. Therefore, this technique has a shoulder alignment that is more parallel with the crease.
The mixed technique usually comes about when a player starts the delivery stride using the front-on technique. However rather than maintaining this open-chested position throughout the delivery, as in the front-on technique, players rotate their shoulders back round to a more side-on position before landing their front foot. This counter-rotation of the shoulders, often while the hips are beginning to rotate in the opposite direction towards the batsman, causes the spine to twist while it is experiencing large forces at back foot and front foot contact. When this sequence is repeated over a sustained period of time, such as during a long bowling spell, it can place large stresses on a player's spine and lead to serious injuries. These can include spondylolysis (a unilateral stress fracture of the pars interarticularis of a lumbar vertebra), spondylolisthesis (a bilateral stress fracture of the pars interarticularis where the vertebral body is displaced anteriorly on the vertebral body below), pedicle sclerosis (increase in bone density of the pedicle and pars interarticularis indicating a stress reaction), and various muscular, tendon and ligament injuries.
The aim of this study
This study, therefore, set out to investigate two main points: first, to determine whether female cricketers bowl with the same actions as male bowlers and, second, to determine whether a similar relationship between the use of the mixed technique and back injuries exists in female bowlers.
The research carried out was completed on 10 junior female cricket players (average age: 17 years), who competed at either national or regional level. Each player was filmed using two video cameras while bowling indoors at a training or selection session. The cameras were situated so that the position and rotation of the player's hips and shoulders could be viewed throughout the delivery action. Information from the two videos was mathematically combined to form a three-dimensional model of each bowler, from which hip and shoulder angles were obtained. Each player was also asked to complete a short questionnaire about their playing and injury history.
What the video showed
The results of the video analysis showed that at the start of the delivery stride, most of the players adopted a more front-on technique. However, by the time their front foot contacted the ground half of them had realigned their shoulders towards a side-on position, thereby demonstrating the mixed technique. This counter-rotation of the shoulders while the hips are rotating in the opposite direction, towards the batsman, is thought to be one of the major causes of lower-back injuries in fast bowlers. The average counter-rotation of the shoulders was 18?, which is very similar to the 17? found by Foster et al. (1989) in a group of 82 young Australian male fast bowlers (average age 16.8 years).
Further analysis showed that six (60%) of the players used the mixed bowling technique, with two (20%) using the front-on and a further two (20%) the side-on techniques. Of the 10 bowlers who were analysed, six were suffering, or had suffered, from a lower-back injury as a result of cricket bowling. Out of these six, three were still using the mixed technique. Two of the remaining three bowlers had recently modified their techniques from the mixed to the front-on technique, and were now injury free. The other player had modified her action from the mixed to the side-on technique, but still appeared to be suffering from a back injury. Players who had modified their techniques had done so on the advice of their coaches in order to avoid further injury.
Another factor that was almost certain to have had an affect on the injuries suffered by these players was overbowling. 60% of them were bowling too many overs for their age group when compared to the recently published Fast Bowling Directives from the England and Wales Cricket Board. In fact, some of the players admitted to bowling up to twice as many as the recommended number of overs during training and in some matches. Several players were playing two or three matches each week, as well as training, which would increase the likelihood of overbowling.
And the results?
The results of this study showed several points. First, the female players bowled with the same actions as male players. The distribution of bowlers between actions was similar to that found by Elliott et al. (1993), who showed that from a group of 24 young male fast bowlers 17% used the side-on, 21% used the front-on and 62% used the mixed technique. With such a small sample, however, the results of this study cannot necessarily be extended to all female cricketers. Second, of the six bowlers who had suffered lower-back injuries, three continued to use the mixed technique, as identified by the large degree of shoulder counter-rotation. The other three bowlers had recently modified their techniques to either front-on or side-on techniques to prevent recurrence of their injuries. Third, there was also evidence of overbowling in the group, which would likely contribute to the injuries.
It is therefore no surprise that 60% of the players had suffered from some form of bowling-related back injury. This problem must be rectified before the game loses too many promising female fast bowlers to serious back injuries. More prospective studies, such as that carried out by Foster et al. (1989) on male bowlers, are needed to further show the link between the use of the mixed bowling technique and lower-back injuries in female cricketers.
Elliott, B.C., Hardcastle, P.H., Burnett, A.F. and Foster, D.H. (1992). 'The influence of fast bowling and physical factors on radiological features in high performance young fast bowlers.' Sports Medicine, Training and Rehabilitation, 3, 113-130.
Elliott, B.C., Davis, J.W.,
Khangure, M.S., Hardcastle, P.H. and Foster, D.H. (1993). 'Disc degeneration and the young fast bowler in cricket.' Clinical Biomechanics, 8, 227-234.
Foster, D.H., John, D., Elliott, B.C., Ackland, T. and Fitch, K. (1989). 'Back injuries to fast bowlers in cricket: A prospective study.' British Journal of Sports Medicine, 23, 150-54.