1. Many ball game sports require precise rapid force production and accurate timing to hit or catch an oncoming target. This study aimed to clarify the accuracy of force production and coincident timing during rapid gripping at different oncoming target velocities of ball game players and non-players. Introduction Twenty young adults (12 ball game players and 8 controls) participated in this study. The participants performed rapid gripping to coincide with the arrival of a moving target using a horizontal electronic trackway (length, 4 m) (Fig. 1). The target moved at a constant velocity, and three different velocities (4 m/s, 8 m/s, and 12 m/s) were randomly produced. The grip force required was 30% of the maximal voluntary contraction (MVC). The peak grip force (PF) and time to peak force (TP) were measured. A constant errors of force (CFE) and timing (CTE) were obtained by subtracting the PF from the target force (30% MVC) and the target arrival time from the TP, respectively (Fig. 2). An absolute errors of force (AFE) and timing (ATE) were obtained from the absolute values of the differences between the PF and target force and between the target arrival time and TP. Force production and coincident timing accuracy during rapid gripping at different target velocities in ball game players Yoichi Ohta Faculty of Health and Medical Sciences, Department of Sports and Health Sciences, Aichi Shukutoku University, Japan Materials & Methods The CFE and rate of force development (RFD) increased with increasing target velocity (Fig. 4a and Fig. 3a), however, the value of the RFD to Pf ratio (RFD/Pf) and force latency were constant across the three target velocities in both groups (Fig. 3b and c). These results suggest that oncoming target velocity does not intrinsically affect the voluntary effort level or ability for rapid force production, regardless of ball game experience. Figure 3. (a) The mean peak RFD and (b), the RFD to peak force ratio (RFD/Pf) and (c) Mean force latency (Latency) in the ball game and control groups in response to three oncoming target velocities. Conclusions Oncoming target velocity does not intrinsically affect the voluntary effort level or ability for rapid force production, regardless of ball game experience. However, ball game experience and oncoming target velocity do affect the accuracy of intensity and timing of rapid force production. contact: t_uzura76@live.jp Results & Discussion Accuracy of force (CFE and AFE) and timing (CTE and ATE) increased at higher target velocities in both groups, and the values for ball game players in both instances were significantly lower than they were for the control subjects (Fig. 4). These results suggest that the oncoming target velocity affects accuracy and variability of force production intensity and its timing during rapid force production regardless of ball game experience. However, this study found that ball game experience enhances the ability to simultaneously control the timing and intensity of rapid force production. Figure 4. (a) Constant force error (CFE), (b) absolute force error (AFE), (c) variable force error (VFE), (d) constant timing error (CTE), (e) absolute timing error (ATE), (f) variable timing error (VTE) in the ball game and control groups in response to three oncoming target velocities.. Figure 2. An example of the time course of force and rate of force development (RFD) measurements in response to a 12 m/s stimulus. Arrows ( ↔ ) show constant force error (CFE), constant timing error (CTE) and force latency (Latency). Zero on the time axis represents target arrival. Figure 1. Schematic representation of the coincident apparatus task. The position of a participant in relation to the electronic trackway during displacement of the visual target