A PRELIMINARY STUDY OF ROTATIONAL SHOT PUT TECHNIQUE
Keywords: shot put, rotational technique, video analysis, kinematic analysis
AbstractINTRODUCTION: The rotational throwing events in track and field, the shot put, discus and hammer throws, are technically very demanding. They involve complex movements performed at high speed in a limited space. The purpose of this study was to identify those characteristics of the rotational technique used by an elite male shot put thrower as they related to his record distances during two consecutive seasons (1996: 18.82 + 0.21 m and 1997: 20.26 + 0.49 m) at two major competitions in Finland. METHODS: Two VHS video cameras were used to record the performances of the athlete from a distance of 20-22 m. One camera was placed to the rear of the throwing circle and the other was placed to the side, and in line with, the midline of the circle. The angle between the optical axes of the two cameras was approximately 90 degrees. The three best trials of each season according to the official competition distances were selected for analysis. These trials were digitized at a sampling frequency of 50 (PAL) or 60 Hz (NTSC) with an Ariel Performance Analysis System. The DLT procedure was used to obtain threedimensional data from these records. The speed, angle and height of release of the shot, the change in speed of the shot during the first double support phase, the first single support phase, the flight phase, the second single support and the second double support phase were calculated. RESULTS: The distance and release velocity of the shot were increased in the second competition on average from 18.82 m to 20.26 (1.44 m or 7.63 %) and from 12.47 to 13.19 m/s (0.72 m/s or 5.77 %), respectively. The angle and height of release decreased from 38.26 degrees to 37.74 degrees (0.52 degrees or 1.37 %), and from 2.12 m to 2.11 m (0.01 m or 0.31 %). The shot speed was always lowest during the flight phase. The actual speeds at the end of the first double support phase, the first single support phase, the flight phase, the second single support and the second double support phase in the first competition were 2.75, 2.48, 1.02, 2.88 and 12.20 m/s, respectively. The changes during the mentioned phases between the two competitions were -0.42, -0.09, +0.52, -0.44 and +0.99 m/s, respectively. No statistically significant differences were found in the selected variables. CONCLUSIONS: The findings suggest that emphasis placed on achieving a large change in the speed of the shot during the second double support phase is well founded and the most influential determinant of the distance of the shot put. A critical phase may be the flight phase in the middle of the rotation when the speed is lowest.
Authors can retain copyright, while granting the International Society of Biomechanics in Sports (ISBS) the right of first publication.