Lectures 1-4 Flashcards
What are the three types of motion?
Translatory (linear displacement)
Rotary (angular)
Curvilinear (plane or planar)
Define Displacement
The change in portion over time
Define Kinetics
Why motion occurs; an analysis of the forces
“what is causing this movement”
Define Displacement
The change in position over time
Describe Translatory Movement
moving in a straight line
gliding
Describe gliding in relation to the joints
Joints have a very small amount of gliding, and often gliding is assessed as an accessory motion
Segments can move in a linear fashion but are also associated with what type of motion?
Rotary
Describe Rotary Movement
Movement of a segment around a fixed axis in a curved path though the same angle, at the same time, at a constant distance through the CoR
(Think of a rotary phone!)
Define Center of Rotation (CoR)
a fixed axis
T or F: Some body segments move around “truly” fixed axes
False
all joint axes shift at least slightly during motion because segments are not sufficiently constrained to produce pure rotation
What is an example of rotary movement (simplified, no joint is truly rotary)
Extension of the knee
Each point in the tibia segment moves through the same angle, at the same time, at a constant distance from the CoR
Most joints move in what type of motion?
Curvilinear (plane or planar)
Describe Curvilinear motion
a combination of rotary and linear motion that produces a curvilinear path about a moving axis (ICoR or IaR)
Joint motion is usually produced by _______ and _______
rolling
gliding
When the motion of a segment occurs around an axis, it is performing what type of movement?
Rotation
When the motion of a segment is occurring along an axis, It is performing what type of movement?
translation
What are the three planes of movement for anatomic position?
Transverse
Sagital
Frontal
The axis of motion is always _____________ to the corresponding plane
perpendicular
All 6 motions combined is called
circumduction
Flexion and Extension occur in opposite directions around the ________ axis and in the ______ plane
coronal
sagittal
Abduction and adduction occur in opposite directions around the ________ axis and in the ______ plane
anterior-posterior
frontal
Medial and lateral rotation occur in opposite directions around the ________ axis and in the ______ plane
vertical
transverse
The magnitude of rotary motion of a segment can be given in either _______ (US units) or _______ (SI units)
degrees
radians
Define range of motion
the magnitude of rotary motion that a body segment moves through or can move through
Displacement per unit time regardless of direction is known as:
speed
Displacement per unit time in a given direction is know as:
velocity
m/sec or deg/sec
The change in velocity per unit time is:
acceleration
m/sec2 or deg/sec2
Force can be measured in ________ or ______
Newtons
Pounds
What is the definition of a “force”
a rush or pull exerted by one object or substance on another
What is the formula for calculating force?
f=ma
Define weight
the pull of gravity on an object’s mass with an acceleration of 9.8m/s2
what is the formula for calculating weight?
W= mass*gravity
What are two examples of internal forces that act on and arise from the body’s own structures?
the pull of muscles on bone
the pull of ligaments on bone
the push of bone on bone
Vector quantities are defined by:
Point of application on the object
direction of push or pull
magnitude of force exerted
How do we name forces?
the source of the force and then the segment that is being acted on
What is the CoM (also called CoG)
the hypothetical point of application at which all the mass of an object or segment appear to be concentrated
The line of gravity (LoG) can also be referred to as the:
gravitational vector
In anatomic position, the body’s COG is approximately where?
anterior to S2
How many vertebra are there and how are they divided?
33 7 cervical 12 thoracic 5 lumbar 5 fused sacral 4 coccygeal
How many intervertbral discs are there?
23
What spinal curves are primary? What is their shape?
cervical and lumbar
Lordotic
What spinal curves are secondary? What is their shape?
Thoracic and Sacral
kyphotic
What is spondylothisthesis?
Fracture of the pars interarticularis
