A three-dimensional cinematographical analysis of the volleyball spike.

The objectives of this study were to describe the volleyball spiking actions used by players in top-level competition, and also to examine the interrelationships between upper limb, lower limb and whole body kinematic variables, and post-impact ball speed in the spiking technique. Two Photosonics Biomechanics 500 cine-cameras operating at a nominal frame rate of 100 Hz were used to film the spiking actions of 10 male senior international volleyball players at the XVI Universiade (1991 World Student Games). Three-dimensional object space co-ordinates of digitized image co-ordinates were obtained using a DLT algorithm and an array of calibration points in the filmed volume. Relationships between lower limb angular kinematics at take-off, centre of mass vertical velocity at take-off and centre of mass vertical displacement (jump height) were examined. Relationships between angular kinematics of the hitting arm and post-impact ball speed were also determined. The mean (+/- S.E.) centre of mass vertical velocity at take-off was 3.59 +/- 0.05 m s-1 and the mean height jumped was 0.62 +/- 0.02 m. As expected, a significant correlation was found between the square of the centre of mass vertical velocity at take-off and jump height (r = 0.78; P < 0.01). No significant correlations were found between lower limb angular kinematics and centre of mass vertical velocity at take-off or jump height. The mean post-impact ball speed was 27.0 +/- 0.9 m s-1, and this was significantly correlated to maximum right humerus angular velocity (r = 0.75; P < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)