Kinesiology Exam 1

We're at OTD Rutgers baby suffer. Received a 100 :)

Kinetics

Study of motions AND the forces causing body motions

Kinematics

Study of JUST motions causing movement, not including forces

Frontal (Coronal) Plane

X and Y axes

Sagittal Plane

Y and Z axes

Transverse (Axial) Plane

X and Z axes

Rotary Motion (Angular Displacement)

Curved displacement around an axis (Center of Rotation)

Translatory Motion

Displacement along an axis in a straight line

Curvilinear Motion

Combined Rotary and Translatory Motion

Curvilinear Motion Axis

Axis is not fixed

Example of Rotary Motion

Shoulder flexion, fatty joint movement
Goniometer

Example of Translatory Motion

Elbow and knee gliding
Compression and Distraction

Example of Curvilinear

Walking and Cheer Motions

Joint Compression

Force on joint creates joint stability
Force push together joint surfaces

Joint Distraction

Force on joint creates joint mobility
Forces separate joint surfaces

Force

Uh force??

Vector

Representation of force

Gravity Force Type

External Force

Center of Mass (COM)

Hypothetical point where object’s mass is evenly distributed
Where gravity is applied DA

Gravity and Center of Mass (COM)

COM is Gravity’s Point of Application

Instability and Base of Support (BOS)

Line of Gravity outside BOS

Stability and Base of Support (BOS)

Line of Gravity inside BOS

How to Increase Stability

Increase BOS, equilibrium adjustments (adjusting COM)

Weight AKA:

Force of Gravity

Internal Force

Forces within body’s structure

External Force

Forces outside body’s structure

Point of Application

Where force is applied

Action Line

Direction of force

Length

Magnitude of force

Newton’s First Law Actual Definition

Object at rest will stay at rest unless acted upon

Newton’s Second Law Actual Definition

The Force acting on a moving object is the product of the Mass and Acceleration
F = m * a

Newton’s Third Law Actual Definition

For every action there’s an equal and opposite reaction

Newton’s First Law Example

Lying down, resting against a wall

Newton’s Second Law Example

Pushing a shopping cart

Newton’s Third Law Example

Hammering a nail on the wall

Linear Force System Definition

Two or more forces acting on the same segment, plane and line

Concurrent Force System

Two or more forces acting on an object at different angles/axes & lines, but end up converging or intersecting

Concurrent Force System Example

Lateral and medial head of the gastrocnemius, they’re both on the Achilles tendon but in opposite X directions

Parallelogram Method

Create a parallelogram with given forces and split in half diagonally to create resultant force

Parallel Force System

Two or more forces acting on an object in the same axis, but not in the same line and do not end up converging

Parallel Force System Example

Turning a steering wheel, turning in a wheel chair, revolving door, see saw

Resultant Force (Vector Sum)

Direction and location of the Sum of unbalanced force(s) on an object in a Concurrent Force System

Force Couple

Forces are parallel and act in the same plane, but in opposite action lines
Type of Parallel Force System
Produces Rotary Motion

Axis

Point of Rotation, Fulcrum

Levers

Rigid segment that Rotates around a fulcrum/axis
Comprised of two forces applied to a lever and create opposing torques

Effort Force (Internal Force)

Force that produces Resultant Torque
Always the winner in torque battle

Resistance Force (External Force)

Force that produces Opposing Torque
Always the loser in torque battle

Point of Application

Where force is being applied

Moment Arm

Distance between Axis and Point of Application

Effort Arm

Distance between Axis and Effort Force’s Point of Application
Moment Arm of Effort Force

Resistance Arm

Distance between Axis and Resistance Force’s Point of Application
Moment Arm of Resistance Force

First Class Lever

EF - A - RF (Axis between)

Axis is between Point of Application of Effort Force and Point of Application of Resistance Force

First Class Lever Example (Axis Between)

Head and Neck:
RF- weight of head
Axis- neck joints
EF- neck muscles

Second Class Lever

A - RF - EF (Resistance Force Between)

Resistance Force is between Point of Application of Effort Force and Axis

Second Class Lever Example (RF Between)

Pushup:
Axis- toes
RF- weight of body
EF- arm muscles

Third Class Lever

A - EF - RF (Effort Force Between)

Effort Force is between Point of Application of Resistance Force and Axis

Third Class Lever Example (EF)

Biceps Brachii:
Axis- elbow
EF- biceps brachii
RF- weight

Torque

Strength of rotation produced by a force
T = F * MA (moment arm)

State of Equilibrium

Internal Torque = External Torque; Net Torque = 0

Mechanical Advantage

Mechanical efficiency of Effort Force compared to resistance force

Optimal Mechanical Advantage

M Ad > 1.0

Non-Optimal Mechanical Advantage

M Ad < 1.0

Concentric Contraction

Active Shortening
Muscle moves segment in direction of pull
Muscle is Effort Force
Muscle shortening creates Active Tension

Eccentric Contraction

Active Lengthening
Muscle moves opposite to segment to slow/control movement against gravity
Muscle is Resistance Force
Muscle lengthening creates active tension

Isometric Contraction

Muscle resists gravity/object, but system is not moving; in rotational equilibrium
Muscle can be either RF or EF
Muscle is not in motion but still creates active tension

Muscle Force & Angle of Application

Angle of Application is used to interact and oppose gravity so body maintains upright posture and produce movement

Gravity & Angle of Application

Angle of Application is used to provide body stability

Biceps @ 90 Degrees Flexion

Greatest Moment Arm for Biceps

Biceps @ Not 90 Degrees Flexion

Moment Arm SUCKS

Anatomic Pulley

Deflects Action Line of muscle force Farther from the joint axis, creating a Larger Moment Arm
Redirects force to make a task easier
Greater moment arm = Greater Torque

Anatomic Pulley Example

Patella in the knee

Gravity & Torque Relationship

The Farther the distance of the COM/Action Line from the Axis, the Greater the Moment Arm/Torque of Gravity
Greater distance COM vs. Axis = Greater Moment Arm = Torque of Gravity

Gravity & Torque Relationship Example

Biceps- gravity has greatest moment arm/torque at 90 degrees flexion
Sit Ups- gravity has lowest moment arm/torque when COM is closer to axis

Resolution of Forces

Breaking down original force into 2 or more forces, their sum is equivalent to the original force
Original Force → Perpendicular Forces & Parallel Forces
Resultant Force → Rotary Forces & Translatory Forces

Perpendicular Forces

Forces that are perpendicular to the long axis (bone)
Fy, Torque, Rotational Component

Rotary Component

Component of original/resulant force that produces Torque
Fy, Perpendicular Force

Parallel Forces

Forces that are parallel to the long axis (bone)
Fx, Compressive and Distractive Forces, Translatory Component

Translatory Component

Component of original/resultant force that creates Compressive/Distractive force
Fx, Parallel Force

Compressive Component - Stabilizing

Angle of Application < 90 degrees

Distractive Component - Tensile

Angle of Application > 90 degrees

Compressive Component Example

Gravity on knee joint at 45 degrees, gravity’s parallel force pushes lower leg bones toward femur

Distractive Component Example

Gravity on knee joint at 135 degrees, gravity’s parallel force pulls lower leg away from femur

Fascicles

Bundled muscle fiber groups

Parallel Forms

Muscles are parallel to long axis
Strap or fusiform

Oblique Forms

Muscles are oblique to long axis
Pennate, unipennate, bipennate, multipennate, triangular/convergent

Circular Forms

Muscles are concentric (surround an opening)

Concentric Contraction and Filaments

Active Shortening
Thin filaments are pulled Toward thick filaments
Cross-bridges between thin and thick filaments are formed

Eccentric Contraction and Filaments

Active Lengthening
Thin filaments are pulled Away from thick filaments
Cross-bridges between thin and thick filaments are broken then reformed in the process of lengthening

Isometric Contraction and Filaments

Muscle fiber does Not change in length
Thin filaments and thick filaments Remain connected
Cross-bridges between thin and thick filaments do not change

Alpha Motor Neuron (AMN)

Neuron that emerges from the anterior horn and extends to the muscle
Initiates muscle contraction

Motor Unit

One AMN and all the muscle fibers it innervates

Passive Tension

Tension created by lengthening the muscle beyond slack; noncontractile
Length increases past max, tension increases

Passive Insufficiency

When a muscle is elongated over 2+ joints simultaneously
Tension is too high for the length of muscle

Passive Insufficiency Examples

Wrist Flexion: wrist flexion creates tension in wrist extensors, pulling them and creating passive finger extension (tenodesis)

Wrist Extension: wrist extension creates tension in wrist flexors, pulling them and creating passive finger flexion

Active Tension

Tension created by contractions of muscle; contractile
Length decreases, tension increases

Active Insufficiency

Muscle crosses too many joints, when the entire muscle contracts the muscle shortens Decreasing Torque and Tension
Length is too short, can’t create enough tension

Optimal Grip in Hand

Slight wrist extension allows for full finger flexion

Synergist Muscle (Accessory Muscle)

Muscles that assist agonists in an action by initiating movement or by stabilizing the agonists

Synergist Example

Radial Deviation- Flexor Carpi Radialis can not perform radial deviation if Extensor Carpi Radialis is not active

Degrees of Freedom

Number of planes or axes which a movement can occur

Uniaxial Joints

1 action type
1 degree of freedom, 1 axis of rotation, 1 plane of motion

Ex: IP joint (flex/ext), elbow joint (flex/ext), radio-ulnar joint (sup/pro)