Anatomy and Kinesiology exam 1

bone and connective tissue injuries often cause _____

joint stiffness

kinesiology

study of movement

kinematics

study of motion w/o cause

osteokinematics

looking at bones and how they move

arthrokinematics

joint and how they move

kinetics

forces that cause motion and effect

rotary/rotational

movement around an axis

ex: elbow

translatory

linear motion, or compression and distraction

ex: scapula gliding on thorax /ribs

saggital plane

left vs. right

frontal/coronal plane

front vs. back

horizontal/transverse

top vs. bottom

axis of rotation

imaginary line perpendicular to the plane of rotation and passing through the center of rotation

medial-lateral axis of rotation

saggital plane

anterior-posterior axis of rotation

frontal plane

vertical axis

transverse

goniometry

Measurement of joint motion

1 degree of freedom

joint can only move in one plane

ex: flexion and extension of elbow, supination and pronation of forearm

2 degrees of freedom

joint can move in two planes

ex: knuckles of fingers, flexion and extension, abduction and adduction

3 degrees of freedom

joint can move in all 3 planes

ex: flexion and extension, adduction and abduction, medial and lateral rotation

open chain

distal or end segment that's free to move, often upper extremities

closed chain

distal or end segment that is NOT free to move, often lower exttremities

synarthrosis

rigid connection between 2 bones of body held together by dense fibrous connective tissue

ex: sutures of skull

amphiarthrosis

junction of bones that's formed w/ fibrocartilage which allow minimal movement and distribute forces

ex: intervertebral discs of spinal cord

diarthrosis

fluid filled joint cavity between bones; majority UE and LE joints. Also called synovial joints

ex: glenohumeral

axial shifting

axes are not stationary.

force

push or pull with or without motion

internal force

force from inside the body

ex: ligaments

active internal forces

muscles

passive internal forces

tension in muscles, connective tissue, ligaments, joint capsule

external forces

produced by forces outside the body

ex: gravity, people, book bags, etc.

1st law- law of inertia

An object at rest tends to stay at rest; an object in motion tends to stay in motion unless acted upon by an external force

2nd law- law of acceleration

Acceleration of the body is

directly proportional to the force causing it, takes place in the same direction in which the force acts,

and is inversely proportional to the

mass of the body.

• F=ma

• Work is equal to the product of the

force applied to an object and the distance the object moves.

3rd law- law of action-reaction

every action has an equal AND opposite reaction

magnitude

amount of force, measure in newtons or pounds

direction

plane the force moves in

resultant force

-sum/combination of two or more forces.

-integrates direction and magnitude of both forces.

-OVERALL MOTION of object is determined by the RESULTANT FORCE acting on that force.

concurrent forces

-same point of application

-pulls in diff. directions

parallel forces

forces occurring in the same plane or direction but with a counterforce in the opposite direction

force couple

-2 or more forces involved

-acting with equal magnitude but opposite direction, creates rotary effect

-creates a moment: tendency of a force to cause rotation around an axis

gravity and resistance

-external forces

-center of gravity = balance point of an object

line of gravity

a vertical line that passes through the center of gravity

base of support

the space between the feet that bears the weight of the body

ways to increase stability

- increase body mass

- increase base of support

- vertically position the cg as low as possible

- increase friction between body and surface

- horizontally position the cg near edge of base of support towards the oncoming external force

compression

A force that pushes on or squeezes a material.

tension

stress that occurs when forces act to stretch an object

bending

a combination of stretching and compression

shear

force directed parallel to a surface; sliding

torsion

a twisting force

torque

ability of a force to cause rotation at an axis

internal torque

product of internal force and internal moment arm (effort force)

external torque

product of an external force and its external moment arm (resistance force)

moment

another name for torque

moment arm

The perpendicular distance from a reference point to the line of action of the force.

levers

a rigid bar that rotates around an axis

first class levers

effort force, axis, resistance force

second class levers

axis, resistance force, effort force

third class lever

axis, effort force, resistance force

mechanical advantage

efficiency of a lever

- E MoA divided by R MoA

-greater than 1 --> powerful lever

-equal to 1 --> balanced lever

-less than 1 --> able to cause more rotation

pulleys

-change the direction of a force

-increase or decrease the magnitude of a force

anatomical pulleys

boney structures that change the direction of applied forces

stiated voluntary muscle

skeletal muscle

-movers of the body

muscle names are based on

- location

- shape

- action

- attachment

- #of heads

concentric activation

muscle shortens

- muscle exerts more internal torque than external torque

- muscles are winning

eccentric activation

occurs when external torque is greater than the internal torque

isometric activation

the internal torques are equal

- no change of muscle length, but still contracting.

agonist

prime mover

antagonist

muscle opposite to prime mover

synergist

muscle that helps prime mover

extensibility

the ability to stretch

elasticity

the ability to return to starting point

irritability

ability to respond to a stimulus

contractility

the ability to shorten

viscosity

the muscles resistance to external forces (heat, ice)

muscle stength and force production is influenced by

- age and sex

- moment arm

- size

- arrangement of muscle fibers

- passive components

- speed of activation

- length-tension of muscle

speed of activation

speed = rate of motion

slower concentric activation

greater forces --> greater actin-myosin bonds are able to form

faster concentric activation

less force, less actin-myosin bonds able to form

muscle strength in men

men anatomically have more muscle bulk and fiber than women

parallel "fusiform"

Fibers are arranged in the same direction along the long axis of the muscle. Spindle-shaped with a central, large belly.

- ex: biceps brachii

pennate "oblique"

Short fibers arranged diagonally along the length of a central tendon. This diagonal arrangement allows for greater strength, but shorter ROM.

msucle fibers influence strength by

more muscle fibers the greater the force potential

what determines strength of muscle activation?

physiological cross-sectional area of fibers

length-tension relationship

The resting length of a muscle and the tension the muscle can produce at this resting length.

active tension

occurs during activation of muscle tissue

passive tension

occurs during the elongation or the lengthening of muscle tissue

-can be stimulated by brain

active insufficiency

when multi-joint muscle can't produce any more force due to SHORTENED length

passive insufficiency

when multi-joint muscles can't be elongated further without damager

tenodesis

occurs in muscles or tendons that cross multiple joints

-ex: wrist in extension --> fingers flex

wrist in flexion --> fingers extend

shoulder complex involves

-scapula

-clavicle

-humerus

articulation of shoulder

scapulothoracic, acromioclavicular, sternoclavicular, and glenohumeral

scapulothoaric joint

NOT A TRUE JOINT

- glides along rib cage

- stabilized by muscles and ligaments

motions of scapulothoracic joint

elevation/depression, protraction/retraction, upward rotation/downward rotation

acromioclavicular joint

-plane

-joint formed from acromion and lateral end of clavicle

motions of AC joint

small amount of movement

-anterior/posterior translation

-superior/inferior translation

sternoclavicular joint

- complex saddle joint

- 3 df

motions of sternoclavicular joint

elevation/depression, protraction/retraction, axial rotation

fibrocartilage (articular discs)

Pads between vertebrae that are shock absorbers

glenohumeral joint

-ball and socket joint

-3 df

-sacrifices stability for mobility

GH motions

-Flexion/Extension

-Abduction/Adduction

-Internal Rotation/External Rotation

-Horizontal Abduction/Horizontal Adduction

static stabilizers of GH

-capsular ligament

-coracohumeral ligament

-glenoid labrum