Comparison of High Velocity and Low Velocity Pitch
Deliveries
Stodden DF, Fleisig GS, McLean SP, Lyman SL, Andrews JR.
Relationship of pelvis and upper torso kinematics to
pitched baseball velocity. Journal of Applied
Biomechanics 17(2):164-172, 2001.
Matsuo T, Escamilla RF, Fleisig GS, Barrentine SW,
Andrews JF. Comparison of kinematic and temporal
parameters between different pitch velocity groups.
Journal of Applied Biomechanics 17(1): 1-13, 2001.
Stodden, DF, Fleisig, GS, McLean, SP,
Andrews, JR. Relationship of Biomechanical Factors to
Baseball Pitching Velocity: Within Pitcher Variation.
Journal of Applied Biomechanics 21(1): 44-56, 2005
Methods
In three
published studies, Dr. Glenn Fleisig and Dr. James R.
Andrews from ASMI worked with other researchers in
studying many of the parameters that affect baseball
pitch velocity. Two of the studies looked between
different pitchers and one study looked at variations
within each pitcher. Motions during delivery were
analyzed using a high speed (200 frames per second)
infrared three-dimensional motion analysis system.
Results
In the study by
Matsuo and others, pitchers with higher ball velocity
were compared with pitchers with lower ball velocity.
Four significant differences were found between these
two groups. Compared to the low ball velocity group, the
higher ball velocity pitchers demonstrated less lead
knee flexion velocity after front foot contact and
greater lead knee extension velocity at the time of ball
release. Extending the lead knee in this manner may
provide stabilization allowing better energy transfer
from the trunk to the throwing arm, and could be a
critical factor in pitch velocity. Maximum shoulder
external rotation and forward trunk tilt at ball release
were also greater in the higher velocity group. Greater
shoulder external rotation causes a stretch of the
internal rotators allowing energy to be stored in these
muscles, and creating greater internal rotation during
the arm acceleration phase.
Two variations
were found in the timing of events. Maximum elbow
extension angular velocity and maximum shoulder internal
rotation angular velocity occurred earlier in the motion
of higher velocity pitchers. The maximum shoulder
internal rotation angular velocity also occurred closer
to the moment of ball release in the higher velocity
pitchers. This optimal timing may aid in generating
higher velocity pitches.
Another finding
of interest is that early in the pitching motion, the
two groups were dissimilar in the timing of their
movements, while their later movement timing was much
more similar. This implies that early trunk and torso
movements are more varied among pitchers than late arm
movements.
In the first
study by Stodden and others (2001), pelvis and upper
torso variables were studied in 19 elite baseball
pitchers. The study found that when the arm was
completely cocked back (that is, maximum shoulder
external rotation, or "MER"), more "open" pelvis and
upper torso orientation correlated with increased ball
velocity. More open pelvis angle at the time of ball
release (REL) also correlated with increased pitch
velocity increased. Additionally, pelvis angular
velocity from front foot contact to MER, and upper torso
angular velocity from MER to REL increased with
increased velocity.
The data
indicate that a pitcher who is able to position himself
properly, and rotate his pelvis and upper torso more
quickly is able to generate greater momentum.
Theoretically, this increase in momentum leads to
greater velocity of the throwing arm and thus greater
pitch velocity.
The most
recent study by Stodden and others (2005) showed that
for a given pitcher, increased elbow flexion torque,
shoulder proximal force and elbow proximal force
produced greater ball velocity. In addition, the
maximum shoulder horizontal adduction occurred later and
maximum shoulder internal rotation occurred earlier at
greater ball velocities. Higher ball velocity also
resulted in decreased shoulder horizontal adduction at
foot contact, decreased shoulder abduction during
acceleration, and increased trunk tilt forward at ball
release.
Conclusion
A pitcher with increased shoulder external rotation,
faster pelvis and upper trunk rotation, and greater
front knee stabilization and extension will throw with
greater ball velocity.
Improved timing to maximize arm velocity closer
to the time of ball release will also help ball
velocity.
Increased torque and force produced at both the shoulder
and elbow will also lead to greater ball velocity.
Copyright © 2000,
American Sports Medicine Institute
November 21, 2008
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