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
Results & Discussion
Introduction
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.
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.
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.
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.
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
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 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: [email protected]