1687, Professor Isaac Newton wrote Principia, the most important
Physics book of all time. Nineteen years after accepting his
professorship at Cambridge University, 45 year old Isaac Newton
organized and published his system of mechanics. While the majority
of Professor Newton's work exceeds the physics required to understand
pitching, his three laws of motion explain how pitchers should
apply force to their pitches.
a. Sir Isaac
Newton's First Law of Motion: The Law of Inertia
'A body remains
at rest, or if in motion, it remains in uniform motion with constant
speed in a straight line, unless it is acted on by an unbalanced
Sir Isaac Newton determined that moving objects continue moving
with constant velocities in straight lines, he refuted Aristotle's
theory that objects were in their natural states only when they
were at rest. Now, moving objects are also in their natural state
when they move with constant velocities in straight lines.
start 'at rest' in pitchers' gloves. However, gravity is an external
force that constantly acts on baseballs. On earth, gravity accelerates
baseballs downward at 32 ft/sec2. To hold baseballs at rest,
pitchers counter gravity's force. Therefore, while pitchers apply
force to baseballs to achieve maximum release velocities, they
continuously overcome the downward force of gravity.
baseballs start moving out of pitchers' gloves, they want to
move with constant velocities in straight lines. Therefore, if
pitchers want to move baseballs in non-straight lines, then they
must apply additional force to overcome the straight-line inertial
pathways baseballs want to follow. This wastes force.
force applications waste force in two ways. First, they require
pitchers to constantly redirect the mass of the baseballs. Second,
they take force away from straight-line force applications. When
pitchers apply force from side-to-side and up-and-down as well
as toward-home-plate, only the toward-home-plate force applications
influence release velocity.
b. Sir Isaac
Newton's Second Law of Motion: The Law of Acceleration
produced by an unbalanced force acting on an object is proportional
to the magnitude of the net force, in the same direction as the
force, and inversely proportional to the mass of the object.'
apply unbalanced forces that act on baseballs. Pitchers want
to maximize the velocity of their pitches. Therefore, we need
to examine what variables influence baseball velocity after force
applications at the moment of release, or, release velocity.
1. The Release
Velocity Formula for Baseball Pitchers
formula form, the law of acceleration is: a = F / m
(a) stands for acceleration which equals the velocity of baseballs
at release (vr) divided by the time (t) pitchers apply toward-home-plate
(F) stands for straight-line toward-home-plate force.
(m) stands for mass which equals weight (wt) divided by gravity.
weigh five and one-quarter ounces or 0.328 pounds and gravity
approximates 32 ft/sec2. Therefore, the mass of baseballs
equals 5.25 / 16 / 32 or 0.0102539 ft. lbs./sec2.
these two factors into the law of acceleration formula creates
the release velocity formula for baseball pitchers.
= F / m
|2. Multiple both
sides by mass (m):
= (F)(m) / (m)
|3. Because (m) /
(m) = 1:
|4. Substitute (0.01)
|5. Substitute (vr) / (t) for a:
(vr) / (t) = F
|6. Multiply both
sides by time (t):
(0.01)(vr)(t) / (t) = F(t)
|7. Because (t) /
(t) = 1:
|8. Divide both sides
(0.01)(vr) / (0.01) = F(t) / (0.01)
|9. Because (0.01)
/ (0.01) = 1:
(vr) = F(t) / (0.01)
release velocity of baseball pitches equals the amount of straight-line
toward-home-plate force that pitchers apply times the time period
over which pitchers apply their forces divided by the mass of
the baseballs or 0.01. Therefore, the variables that determine
what release velocities pitchers achieve are their straight-line
toward-home-plate force applications and the time period or distance
over which they apply their forces.
uniform acceleration study determined that pitchers apply force
from leverage through release for approximately 0.2 seconds.
If we assume that pitchers want release velocities of at least
90 miles per hour, then we can determine how much straight-line
toward-home-plate force they must apply for two-tenths of second.
To determine the feet per second of ninety miles per hour, we
multiply 1.467 times 90 and learn that 90 mph equals 132 ft/sec.
Therefore, for vr, we substitute 132 ft/sec.
|1. Release Velocity
(vr) = (F)(t) / (0.01)
|2. Substitute known
= (F)(0.2) / (0.01)
|3. Divide both sides
/ (0.2) = (F)(0.2) / (0.2) / (0.01)
|4. Because (0.2)
/ (0.2) = 1:
= (F) / (0.01)
|5. Multiply both
sides by (0.01):
= (F)(0.01) / (0.01)
|6. Because (0.01)
/ (0.01) = 1:
|7. Change sides:
= 6.6 lbs.
The Release Velocity Formula shows that when pitchers apply 6.6
pounds of straight-line toward-home-plate force for two-tenths
of a second, they achieve release velocities of ninety miles
per hour. To better understand the interrelationship between
release velocities and force and application time, let us assume
some other numbers.
pitchers decrease their application time forces by five-hundreds
of a second, the force required for pitchers to achieve ninety
miles per hour release velocities increases to 8.8 lbs. Therefore,
the application time directly influences the amount of force
that pitchers have to apply to achieve their desired release
velocities. For example, when pitchers uniformly apply 6.6 lbs.
of force for 0.22 seconds, then they achieve release velocities
of 145.2 ft/sec or 98.98 mph.
c. Sir Isaac
Newton's Third Law of Motion: The Law of Reaction
Action force, there is an equal and oppositely directed Reaction
law of reaction requires that pitchers apply force toward second
base equal to the force that they apply to baseballs toward home
plate. If pitchers want to apply greater force to their baseball
pitches, then they have to apply greater force toward second
base. Pitchers have three ways with which they can apply their
oppositely directed force. First, pitchers can push harder against
the pitching rubber with their rear legs. Second, pitchers can
push toward second base with their stride legs. Third, pitchers
can use the inertial resistance of their body mass against which
to apply oppositely directed forces.
The Pitching Rubber
push against the pitching rubber with their rear legs to start
their bodies forward. At one time, pitching coaches instructed
pitchers to powerfully drive against the pitching rubber. However,
when pitchers developed serious shoulder pitching injuries, they
stopped emphasizing the rear leg drive. Some recent pitching
coaches recommend that pitchers do not push off the pitching
rubber at all, rather, pitchers should simply fall forward. The
Law of Reaction requires pitchers to push off the pitching rubber,
but the position of their pitching arms is critical. I will discuss
this in great detail in Chapter Twenty.
ground provides pitchers with a resistance against which to apply
their oppositely directed force. To achieve greater oppositely
directed force, pitchers can drive off their stride legs. If
pitchers use this stride leg drive technique, then they also
lengthen the driveline over which they apply force. When pitchers
increase the length of their drivelines, they increase the application
time of their force.
Intrinsic Inertial Resistance
require hundreds of hours of proprioceptive awareness to learn
how to incorporate inertial resistance into their equal and oppositely
directed forces. Infants do not have inertial resistance instinct.
However, kittens do.
pet lovers cradle upside down kittens with their hands twelve
inches above soft, injury-preventive cushions and unexpectedly
remove their hands, kittens instinctually use their lower extremities
as inertial resistance against which to rotate their torsos and
upper extremities to face downward, and, then, they use their
rotated upper torsos and upper extremities as inertial resistance
against which to rotate their lower extremities to land on all
four feet. Pitchers require hundreds of hours of practice to
learn their perfect equal and oppositely directed reaction techniques.
d. Dr. Mike
Marshall's Three Laws of Force Application for Baseball Pitchers
Isaac Newton wrote his laws with regards to the motion of objects.
Kinesiologists study Newton's laws in light of the movement of
objects or center of masses. When Professor William H. Heusner
explained Newton's laws to my Kinesiology class, I immediately
understood that Newton's three laws also explained how athletes
should apply force to projectiles, including themselves. Therefore,
I developed my three laws of force application for baseball pitchers.
I leave it to others to develop the three laws of force application
for other sport/work activities.
1. To achieve
their maximum release velocities, pitchers must apply their force
from leverage through release in straight lines.
must minimize all side-to-side movement of the baseball behind
their bodies during the preparation or transition phase of the
pitching motion. When pitchers reverse rotate their bodies beyond
where the line extending the points between the tips of their
shoulders (acromial processes) points toward home plate, they
take the baseballs too far behind their bodies. This reverse
rotation causes side-to-side baseball movement that wastes force
and causes unnecessary stress on the pitching arm. I teach a
technique that enables pitchers to keep their drivelines as straight
2. To achieve
their maximum release velocities, pitchers must uniformly apply
their maximum forces over the greatest displacement or time period
must extend the length of the driveline between leverage and
release. High speed cinematographic studies show that pitchers
release their pitchers about five and one-half or six feet in
front of the pitching rubbers. They release their pitches behind
their stride foot, beside the heads. I teach a technique that
enables pitchers to extend their drivelines up to two feet farther
out front. I call this concept, 'hidden velocity.'
3. To achieve
their maximize release velocities toward home plate, pitchers
must increase the magnitudes of their straight line toward second
must increase the force that they apply towards second base.
However, the anatomy of the shoulder requires great care. If
pitchers simply push extra hard off pitching rubbers without
regard for the position of their elbows relative to their acromial
lines, then they can irreparably damage their shoulders. I teach
a technique that enables pitchers to apply greater force toward
second base without endangering their shoulders.