Striking a moving ball, particularly a ball that is travelling at pace, is a complex task. Add a little lateral swing to the ball’s trajectory and the task becomes even more difficult. Just ask an opening batsmen in cricket. Or a baseball player trying to hit a curve ball.
With this in mind, an important question to ask is: How does a swinging ball affect the coordination of movements when attempting to strike a ball?
Vishnu Sarpeshkar and colleagues investigated this issue with elite and club-level cricket players in Australia.
43 male cricketers (all identified as batsmen) participated in the study. The breakdown of participants was as following:
- Adult skilled group – played senior state cricket (n = 13). 4 of these players were members of the Australian National Squad.
- Youth skilled group – played youth state cricket in under 19’s or under 17’s (n = 10).
- Adult club group – played senior club cricket (n = 10).
- Youth club group – played youth club cricket (n = 10).
All participants were required to bat against a ProBatter ball-projection machine. This ball machine couples the projection of the ball with a visual image of the bowler during their run-up and delivery stride.
Participants batted in two conditions. In one condition, the ball was projected with ether a straight trajectory or a curved trajectory. Using cricket terminology, the curved trajectory deliveries were a mixture of out-swingers (swinging away from the batter) and in-swingers (swinging towards the batter). In the other condition, the ball did not swing.
In both conditions, the balls were projected at 119 kph and the landing location of the balls varied between full, good-length and short.
There were a number of interesting results in this study. 6 of the key findings are outlined below.
- As expected, the skilled players (adult and youth) displayed better bat-ball contact than than the club players – regardless of whether the ball swung or not.
- The key difference between skilled players and club players with regards to coordination was the relative timing of movements. The timing of the downswing initiation relative to the completion of the front foot stride was more consistent for skilled players.
- When the ball swung away from the batter (out-swing), bat-ball contact was poorer for all players compared to balls that travelled straight or balls that swung towards the batter (in-swing).
- When there was a possibility that the ball could swing, players coordinated their movements differently – even if the delivery was projected without any swing. Club players were more affected by the possibility of swing compared to the skilled players.
- Players adapted to swing by delaying their movements. Delayed movements were compensated by modifications to the bat swing – typically an increase in angular velocity in the downswing. In fact, when there was a possibility of swing, club players sometimes displayed behaviour akin to an expert due to the delayed movements (i.e., the relative timing between the front foot stride and the initiation of the downswing resembled a skilled player).
The authors explained the implications of the results as follows:
“These findings support the benefits of establishing task-specific training protocols that are conducted under high contextual variety that more accurately represent the conditions experienced in the performance environment (i.e., competition). Although a blocked training paradigm might help beginners learn to coordinate movement effectively, prolonged exposure may lead to predetermined motor-programmes that are organised prior to the execution of the movement. By creating an environment where performers are uncertain of the ball’s flight path, such as those encountered during competition, performers are more likely to develop movement patterns that allow for changes in specific kinematic parameters with changes in ball-flight.”
In other words, when planning practice, be specific, promote variability and embrace the importance of adaptability.
Sarpeshkar, V., Mann, D. L., Spratford, W., & Abernethy, B. (2017). The influence of ball-swing on the timing and coordination of a natural interceptive task. Human movement science, 54, 82-100.