Kinesiology Quizam

Motion definition

the act or process of changing place or position with respect to some *reference* object

Second Class Lever

the resistance is between the effort and the fulcrum

three characteristics of force

○ Magnitude - amount of force being applied ○ Point of Application- Point at which force is applied to an object ○ Direction- Direction of a force is along its action line

Rectilinear = Curvilinear = Circular motion or special curvilinear: Specialty: Reciprocating Motion: Oscillatory motion =

Rectilinear = think of pushing a box from point A to point B Curvilinear = think of bowling a bowling ball Circular motion or special curvilinear: the object is spun in a circular motion prior to following a linear trajectory path, like a softball pitch Specialty: Reciprocating Motion: repetitive translatory motion aka bouncing a ball Oscillatory motion = repetitive motion on an arch (pendulum

Relative motion= for an object/human is defined in relation to ____

Relative motion= for an object/human is defined in relation to the specific reference object or point

Moment arm is the

Moment arm is the perpendicular distance from the line of force to the axis of rotation.

Third Class Lever

effort in the middle

external vs internal factors that modify motion

external: Friction, Air resistance, Water resistance internal: Joint friction, Structural anomalies, atmospheric pressure (example: plane taking off), Interfering soft tissue

First Class Lever

fulcrum in the middle (E = Effort A = Axis or fulcrumR = Resistance)

linear motion: angular motion:

linear motion: translatory angular motion: rotary

mass is ____ and weight can ____

mass is CONSTANT and weight can VARY

Classification of Levers: Three points on the lever

1. Fulcrum 2. Effort force point of application 3. Resistance force point of application

#1 Law of Inertia

A body continues in its state of rest or of uniform motion unless an unbalanced force acts on it. - An object at rest remains at rest. - An object in motion remains in same motion - Unless acted upon by an outside force.

Eccentric Force

A force applied outside the centre of mass, resulting in angular motion (a force whose direction is NOT IN LINE with the center of gravity of a freely moving object OR the center of rotation of an object with a fixed axis of rotation.)

ALL JOINTS produced _____ motion

ALL JOINTS produced ANGULAR motion

Angle of Pull less than 90 degrees: Non-rotary force is directed ____ the fulcrum Angle of pull more than 90 degrees: Dislocating force is directed ______ the fulcrum

Angle of Pull less than 90 degrees: Non-rotary force is directed toward the fulcrum Angle of pull more than 90 degrees Dislocating force is directed away from the fulcrum

Anatomical Pulley:

Changes the angle of pull of the muscle providing the force. ex. kneecap/patella

Concurrent Forces: Parallel Forces:

Concurrent Forces: Act at the same point of application at different angles. Parallel Forces: Forces not in the same action line, but parallel to each other. - Three parallel forces: Two upward, one downward

FORCE= product of ____and _____

FORCE: product of mass and acceleration Expressed in newtons

#3 Law of Reaction

For every action there is an equal and opposite reaction.

Summation of Forces

Force generated by muscles may be summated from one segment to another Example: Throwing

Ground Reaction Forces

Ground Reaction Forces: In locomotion on the surface of the earth reaction force is called ground reaction force

Mechanical Axis

It is Straight line that connects the midpoint of the JOINTS at either end of the bone

Kinetics vs kinematics

Kinematics - description of motion and includes consideration of time, displacement, velocity, acceleration, and space factors of a system's motion Kinetics - study of forces associated with the motion of a body Kinetics: focuses on what forces are producing or changing motion (and how its happening) force= linear torque= angular spinning/rotating= torque Kinematics: describing motion with no regard for what is causing the motion to occur: Time, displacement, velocity, and acceleration Motion can be straight (linear) or rotating (angular)

Scalar vs. Vector

Scalar: single quantities (magnitude) represented by size or amount (lacks direction) Vector: describe both quantity (magnitude) and direction Represented by an arrow and length is proportional to the magnitude Displacement = vector quantity Combination of vectors = resultant of R Can be added or subtracted Done by joining the HEAD of one, and the TAIL of the next

Static vs dynamic

Statics: all forces acting on the body are balanced Example: force couple (equal balance) Dynamics: unbalanced forces - cause some change in speed or direction

The Magnitude of the_____ relative to the magnitude of the ______ is the determining factor in ________.

The Magnitude of the force relative to the magnitude of the resistance is the determining factor in causing an object to move.

#2 Law of Acceleration

The acceleration of an object is directly proportional to the force causing it and inversely proportional to the mass of the object.

muscle ANGLE of PULL is the ...

The direction of a muscular vector force is the direction of the line of pull of the muscle - the ANGLE between the Line of Pull and the mechanical axis of the bone

for a muscles force, the point of application is usually...

Usually the muscle's insertion or distal attachment

Torque

a turning or twisting eccentric force