Factors influencing performance of the badminton smash: racket and technique

Shaft stiffness was found to have no significant effect on performance using a group-analysis. Individual analyses found some participants performed better with specific rackets. Elite participants, however, were able to make effective use of all shaft stiffnesses with no changes in performance across the range used.

Performance (racket head speed and deformation velocity) was more variable with the most flexible racket compared to the stiffest. From a technique perspective, players who achieved more counter-rotated trunk axial rotation positions, delayed the forward pull of the shoulder and achieved more externally rotated shoulder positions produced greater shuttlecock speeds. Joint orientations at impact were similar across participants.

It was found that the two largest contributors to racket head speed were shoulder internal rotation and wrist flexion (35.1 and 18.0 m s-1) occurring 10 and 5 ms prior to impact, respectively, where racket head speeds at impact achieved were 58.2 5.1 m s-1. From a kinetics perspective, it was found that the ability to produce larger shoulder internal rotation moments (71-84% of swing phase) was associated with greater racket head speed.

These findings can be explained by the concentric phase of the movement being enhanced by the stretch-shortening cycle and allowing more work to be done by joints completing greater ranges of motion. A case-study analysis found no changes in joint angular velocities when using high vs. low moment of inertia rackets. In summary, the effects of two important racket properties and technique parameters associated with greater smash speeds were explored and provide insight as to how performance can be improved.</p>