Force Production, Direction, Absorption Flashcards
P1
The What
Increase or alter the mass used to produce force (body or implement)
The Why
F=MxA
When greater force is required, we can engage and use more, larger, or stronger
muscles, or use more groupings of muscles that can contribute and are available to the action (in a sequential manner)
OR increase the mass of the implement employed in the action.
The How
Trunk rotation, sequential movement, weight shift/transfer, joint flexion, …
In relation to striking activities where an implement is involved …
– i.e use a heavier bat in baseball or cricket; weighted club head in golf; vary mas (weight)
P2
The What
Increase or alter the speed of the body, body segment, or implement imparting force to the object
The Why
In throwing or striking actions the force developed in the body is transferred to a body segment/implement which in turn imparts the force to the object thrown or struck.
Increasing the speed of the body part or movement action (meaning velocity increased over the distance of the movement and acceleration occurred)
F=MxA
The How
When greater force is required, and we wish to increase the acceleration of the Force equation, the mover can quicken the movement to assist in generating acceleration and ultimately the force that is imparted to the object and needed to send the object by employing “fast” movement, “snapping” within an action (e.g., snap of the wrist), quickness, pace, increased cadence or rhythm, etc…
P3
The What
Increase or alter the ROM of the body segment or implement imparting force to the object.
The Why
When greater amounts of force are needed, greater T&D in the action/movement can be used to increase the T & D through which speed, an increase in velocity, and ultimately acceleration to be developed.
An increase in speed, velocity, or acceleration can be produced and, in the end, transferred to the object as a force at the moment of contact or release.
F = M x A
The How
Time and distance can be increased by increasing the Range Of Movement of the body segment/implement imparting force
ROM can be increased in two primary ways …
Employing a larger backswing (e.g., rotating the striking or throwing arm away from intended direction of flight; assume a forward back stride position; employ opposition, trunk rotation, weight
transfer)
Using a longer or lengthened lever (reaching contact; grip near the end of implement) that can be efficiently and effectively controlled by the performer (remembering the NB of summative and
sequential motion).
P4
The What
Set the body in motion prior to contact or release, BUT at the moment of
contact/release, stabilize the body
The Why
• When force/maximum force is desired, movers should develop & effectively transfer momentum through the use of preliminary movements
• Momentum = Mass x Velocity of an object
The greater the velocity or mass of an object the greater potential for the momentum of the object
Increase mass, velocity, or both of an object, and momentum will increase
With no velocity, however, there is no momentum
The motion before contact/release is another way to achieve an increase in velocity (or in other words
accelerate)
Resultant increases in velocity and momentum, from preliminary movements, can be transferred to
the object at the moment of contact/release.
• THE “BUT”* HERE IS … the body should be stabilized at the moment of
contact/release
So that the increase in velocity/acceleration & momentum that has been generated can be maximally transferred to the object (body or external object) and not dissipated or lost through an unstable body position
P5
The What
Stabilize the body segments involved in an action.
The Why
• Stabilizing the body segments involved in action provides a firm base, brace, or anchor for that body segment from which to create and ultimately transfer force. Prevents the dissipation of force before contact or release as it assists with the maximum action being directed into the object.
The How
• At times we can stabilize the entire body through contact with the ground, but often
movement occurs in the air
• In these types of movements, the body parts used in a throwing or striking action can be stabilized by engaging the musculature of the body structure closest to and attached to this body part (such as the trunk or torso primarily, but also hips, chest and back muscles).
P6
The What
Employ, increase, or alter a follow-through
The Why
The follow-through ensures velocity and momentum developed by the implement or body part do not decelerate before contact or release.
By employing the follow-through, movers can ensure they don’t slow down or decelerate the action before contact/release occurs
Prevents the dissipation of force (through deceleration) that can be generated prior to contact or release
The follow-through is what happens after contact/release; CAN NOT add more force (via acceleration/velocity) by employing it; the follow-through is used to prevent deceleration and increase
the likelihood that the highest rate of acceleration is occurring prior to contact/release.
Prevention of injury is a secondary, not the primary, reason for use of the follow-through
The How
The follow-through is the continuation of the movement (throwing, kicking, striking, or releasing action) that occurs immediately after release or contact (e.g., Hockey stick continues forward and away
from the body after contact; Throwing arm continues forward and downward across the body)
When MAX force production is not the primary focus, or when a rule violation could occur as a result of its use, the
follow-through can also be altered (shortened, eliminated, redirected, etc…)
P7
The What
Use of a firm striking surface
The Why
When maximum force or distance is desired, the use of a firm striking surface
prevents force from being absorbed by that striking surface
Allows for a greater amount of force to be imparted to the object
Results in a Greater reaction off of the striking surface because the magnitude of
the force into the action is maintained, and resultant reaction achieved = N3L
The How
Through the use of:
– Hard, solid surfaces
– Firm Grip
– Fully engaging the body part directly involved in the action
D1
The What
Apply force in relation to the object’s center of gravity (COG) to
prevent or create spin
The Why
• Rotation occurs as a result of off-center application of force in relation to the COG of an
object (right, left, top, and backspin).
• An object will always want to move in the area of least resistance or lesser air pressure
(Bernoulli’s principle).
The amount of force and where the force is applied on an object dictates the amount of and where the greater or high-pressure area will be.
The amount of spin given to an object depends on how much force is applied and how far it is applied from the object’s COG
The object will want to move or spin away from the contact area to the area of least resistance or air pressure (Magnus Effect), creating rotation/spin.
The How
The rotation occurs when force is applied at a distance from the axis of rotation.
In ball games, such as tennis and volleyball, movers can
manipulate the amount of spin given to the ball.
Athletes who want to rotate apply the same mechanical principles to themselves.
D2
The What
Know where the center of the object is (eyes on
object/eyes on target at the moment of contact or release)
Why
In order to contact the object where you want to contact the object, in relation to the COG and in accordance with the demands of the movement
When not in possession of the object you do not have the advantage of kinesthetic awareness to locate the object and its COG. When in possession of the object you have the advantage of kinesthetic awareness to locate the object and its COG
The How
Eyes on an object when striking (when not
in possession of the object) at the moment of contact look at the target at release when throwing.
Eyes on the target when throwing (when in
possession of the object) at the moment of release
D3
The What
Contact an object with a large flat surface
The Why
Facilitates & increases the likelihood of applying force in relation to the COG
of the object where desired and in the desired direction for contextual purposes and objectives
and to avoid an unpredictable result, such as an altered flight path
The How
- use as large a contact or release area as possible
= think big bertha in golf; large driver heads; open hand in striking
actions such as volleyball spike or handball clear; fingers spread apart on
throwing actions
D4
D4
Attend to external forces that will alter the flight
of a projectile
= the Why
- Projectiles will react to external forces they are exposed to such as gravity, air, and
friction.
= Be aware and attempt to compensate for these if and where they exist.
= Attempt to overcome and use to the advantage of the performance.
The How
Adjust the release angle of projection and choose optimal release
points in the swing arc that will alter the flight path
- e.g. when distance is desired, project an object at a 45-degree angle so
effect of gravity not immediate
- e.g., when speed is more desirable, release point near the center of the swing arc the
the angle should be used
= Create and employ spin (again highly related back to D1) !!!
A1
WHAT
Absorb the force from a position of stability in line with the oncoming force
WHY
In order to keep the COG above BOS AND the LOG passing through BOS
Maximize the time and distance for the COG/LOG to travel in the same direction as the oncoming force, within the BOS, and still remain above/passing through the BOS
To maintain a stable, balanced position to allow for an increase in the time and distance over which to dissipate the force and absorb the force effectively with control
HOW
Establish a large enough BOS in relation to the Direction and Amount of the oncoming force
Shift the COG & LOG toward the edge of BOS
closest to the direction of the oncoming force.
e.g. receive out front
Lower the COG
A2
What
Maximize the absorbing surface area
WHY
To spread out, or dissipate the force, over a greater contact or receiving surface area
To reduce the “force per unit area” taken on by anyone part or portion of the receiving surface.
Employing the understanding of reducing the action, in order to reduce the reaction, from the receiving surface through the manipulation of that receiving surface area (N3L)
HOW
Increase or maximize the surface area available to be used and is used to receive and absorb the oncoming force.
Use as big a surface area or larger surfaces, and as much of these surface areas as is manageable, possible, or is available to absorb the force.
Change the angle of incidence; use both hands; spread the hands apart, land on two feet, use the bottom of the foot vs the toe, use the chest vs the head in receiving a ball, rebound the object from
one surface to another to increase the amount of receiving surface, etc…
Use conforming receiving surfaces vs non-conforming surfaces, wherever & whenever
possible
A3
WHAT
Give in the amount and direction of the oncoming force
WHY
Gradually reducing and absorbing a force to “increases the time, distance, or space over which to” dissipate and absorb that force allows for a gradual reduction, or dissipation of the force, over the time, distance, and or space used in the motion
HOW
By “Giving “ or “cushioning” the object at the moment of contact
Making early contact with the object (in relation to the amount of force approaching); reaching out and meeting the object early
» e.g., if caught, at the moment of contact meet ball with a straight arm
Drawing the object in its original motion, into the body, or in the same direction of the oncoming force, in order to develop and USE more time and distance over which to dissipate and absorb the force of the object.
» E.g., if catching, once contact with straight arms is made with the object, the mover then bend at each of the joints within the arm (fingers, wrist, elbow, shoulders) until the object has been controlled
Use of giving or cushioning receiving surfaces versus hard surfaces
Use of space (e.g., loose grip versus tight grip on the implement)
Employing the use of protective equipment
Space between the body and the equipment, and the give within the equipment, provide another cushioning effect and increased time and distance over which to dissipate the force
How does spin impact the rebound of an object
No spin: Angle of incidence = angle of reflection
Top spin: Angle of incidence > angle of reflection
Bottom spin: Angle of incidence < angle of reflection
