A THREE-DIMENSIONAL KINEMATIC ANALYSIS OF THE VOLLEYBALL JUMP SERVE
AbstractINTRODUCTION The aim of this study was to describe and analyse biomechanically the actions used by international volleyball players performing the jump (spike) serve. Although attack spiking has been studied in detail (for example Coleman et al, 1993), there has been no research comparing the techniques with those required for successful jump serving. METHODS Eleven International players (Great Britain) were filmed in competition and training using two gen-locked video cameras filming at 50Hz. Three-dimensional object space co-ordinates of digitized image co-ordinates were then obtained using a DLT algorithm and an array of calibration points in the filmed volume using software written by Bartlett (1990). Relationships between lower limb angular kinematics, centre of mass velocities and vertical displacement were analysed. Associations between upper limb kinematics, trunk angular movements and post-impact ball speeds were also examined using Pearson Product Moment Correlations. RESULTS Centre of Mass (CM) vertical and horizontal take-off velocities were equal in magnitude (2.76 m.s-l), and there was no significant correlation with any of the lower limb angular kinematics. Jump heights (CM vertical displacements) were significantly correlated to the square of the CM vertical take-off velocities (r = 0.74, P = 0.005), but not to lower limb variables. Mean post-impact ball speeds were 23.7+2.lm.s-1 and were only significantly associated with the hitting hand speed (r = 0.66, P = 0.013) and maximum humerus-trunk angular velocity (r = 0.55, P = 0.041). Trunk rotational kinematics did not correlate significantly with ball speeds. CONCLUSIONS The results from this study concerning simple relationships between limb kinematics and performance variables during the jump serve confirmed the research of Coleman et al(1993). CM horizontal velocities and displacements were higher than those reported for spiking, reflecting the linear translation required in the jump serve. It is intended that the results obtained from this study will be used in a mathematical model (such as those which have been developed for the spike) to examine tactical effectiveness. REFERENCES Bartlett, R.M. (1990). The definition, design, implementation and use of a comprehensive software package for the Acorn Archimedes A440 microcomputer. Communication to the XIII International Symposium of Biomechanics in Sports, Prague. Coleman, S.G.S., Benharn, A.S., Northcott, S.R. (1993) A three-dimensional cinematographical analysis of the volleyball spike. Journal of Sports Sciences, 11, 295-302.
Coaching and Sports Activities
Authors can retain copyright, while granting the International Society of Biomechanics in Sports (ISBS) the right of first publication.