The Magnus Effect is effectively what gives the ball its swinging motion in the air, and is in relation to fluid dynamics and lift. The theory behind the Magnus effect suggests that a spinning ball will ‘grab’ and drag the nearest layer of air to it due to the friction between the air and the ball, causing these boundary air particles to spin with the ball (Blazevich, 2012). As the spinning air collides with the oncoming air a pressure differential is produced. As Bernoulli’s theorem suggests, the air on the side of the ball colliding with the oncoming air causes a higher pressure, whilst the on the side the speed of the air flow is unimpeded, allowing for a low pressure to remain. (Blazevich, 2012).
The Magnus force that one places on a ball is the spinning action placed on it that in turn, causes it to spin. With this being said, it is acceptable to assume that a greater amount of spin placed on the ball, or greater Magnus force, will allow for a greater swinging trajectory. The speed the ball is travelling through the air also effects the amount of spin due to ‘Newton’s Third Law’, that suggests the more air being pushed by the ball will have an opposite amount of air pushing against the boundary layer of air, causing higher pressure on the outside arc of the ball (Lees, et al, 2010).
In relation to soccer it is important to understand that Magnus force is not created in relation to the direction in which the ball is struck, but is affected by the angle it’s struck. Therefore we can assume that in order for an individual to maximise the effectiveness of the swing motion of their kicks trajectory, they will require an emphasis on the angle in which they strike the ball and the momentum transferred into the ball. The direction of the kick will also need to be carefully monitored by the individual as to correct for the trajectory of the balls swing.
Above is an example of the Magnus effect on a soccer ball (Google Images, 2014)