Author(s): SUDO, Y., KAWAMOTO, Y., IINO, Y., YOSHIOKA, S., MURAI, A., Institution: THE UNIVERSITY OF TOKYO, Country: JAPAN, Abstract-ID: 1758

INTRODUCTION:
The relationship between speed and accuracy in overarm throwing remains debated, with studies showing varied findings: faster throws may decrease accuracy (1), there may be an optimal speed for maximum accuracy (inverted-U relationship) (2), or no significant relationship between speed and accuracy at all (3). Previous research has highlighted task complexity and the throwers experience as key influences on the speed-accuracy relationship in throwing tasks. However, differences in the physical conditions of experiments should also play a role. By properly accounting for physical factors and subtracting their effects, a clearer understanding of human motor skills can be obtained. Previous research implies that a small, light ball or longer throwing distance might exhibit an inverted-U speed-accuracy relationship. This study aimed to reveal how different pitching conditions and ball flight physics affect throwing speed and accuracy and to clarify the characteristics of human motion relating to the throwing speed-accuracy relationship.

METHODS:
Ball flight post-release of overarm throwing was simulated (4), targeting a vertical plane 0.9 m above the ground. The throwing speed was increased from 15 m/s to 33 m/s in 3 m/s increments. Constant white noise was added to the ball kinematic variables at ball release with respect to speed and throwing angle, centered on the combination of speed and throwing angle that would hit the center of the target. Accuracy was assessed by the vertical variability of the ball landing position across 1,000 simulations. Flight simulations were performed with two types of balls —a handball (mass: 0.45 kg, radius: 0.095 m) and a cricket ball (mass: 0.16 kg, radius: 0.036 m)— and two distances (short: 7 m and long: 20.14 m).

RESULTS:
Simulations showed that for short distances, increased throwing speed led to a gradual decrease in landing variability—27.0% for handballs and 23.5% for cricket balls at 33 m/s compared to 15 m/s. At long distances, variability dropped sharply with speed increases, with handballs and cricket balls seeing decreases of 69.3% and 74.3%, respectively. The difference in variability between ball types was minor, ranging from 1.89% to 6.36% for short distances and 10.6% to 17.7% for long distances at the corresponding speeds.

CONCLUSION:
Throwing distance primarily affected the speed-accuracy relationships in overarm throwing tasks, while the type of ball had little effect. Contrary to the hypothesis, accuracy monotonically increased with higher throwing speeds, not replicating the anticipated inverted U-shaped relationship for the long distance. It was assumed that the variability of ball motion at release would remain constant regardless of the throwing speeds, but it is possible this variability might increase at faster throwing speeds.

REFERENCES:
1) Etnyre, Percept Mot Skills, 1998
2) Freeston et al., Eur J Sport Sci, 2007
3) Vila & Ferragut, Int J Perform Anal Sport, 2019
4) Clanet, Annu Rev Fluid Mech, 2015