Flashcards in Principles Deck (43):
T or F 'z' is positive to the person's right
which directional plane is positive anteriorly (direction of forward progression for gait)
what axes form the frontal (coronal) plane
vertical (y) and mediolateral (z)
what axis does frontal plane motion rotate about?
x axis (anteroposterior)
Transverse Plane is formed by
the anteroposterior (x) and mediolateral (z) axes
what axis does motion in the transverse plane rotate about
sagittal plane is formed by
the vetical (y) and antero-posterior (x) axes
motion in the sagittal plane rotates about which axis
mediolateral (z) axis
what is kinematics? example?
description of motion
displacement, velocity, acceleration
what is kinetics?
description of forces
what is translation?
what is angular displacement measured in?
what is true about linear and angular motion regarding human movement
it's usually a combination of the two
What's the difference between external and internal forces?
external - forces acting on the body (gravity, a weight in hand)
internal - forces acting inside the body (muscle force, passive constraints)
what is the moment arm defined as
perpendicular distance between line of action of the force and the axis of rotation
hyper/hypo-mobile, smooth/jerky is an example of which kind of description of movement
The standard for 3-dimensional analysis is
International Society of Biomechanics standard
T o F Scalar Quantities can only add quantities of the same units
which quantity have magnitude AND direction
mass is a
weight is a
vector (mass x gravity)
distance is a
displacement is a
point at which the entire mass of an object can be considered to be located
Balance point for an object
center of gravity
Where is the Whole Body COM
Newtons 1st Law
object at rest will stay at rest unless acted on by an unbalanced external force. object in motion will stay in motion unless acted on by an unbalanced external force
When is something in Static equilibrium
when the sum of the forces = 0
Newtons Second Law
sum of Forces = ma
Newtons third law
for every action, there is an equal and opposite reaction
collinear force system
forces act on the same segment
(tug of war)
concurrent force system
lines of action are at angles to each other
First Class Lever
external force and internal force on opposite sides of fulcrum
Second Class levers
fulcrum and internal force on opposite side of the external force
third class levers
fulcrum and external force on opposite sides of internal force
which lever is very common in the body
What happens when you multiply a vector by a scalar
get a vector
How do you decrease stability
decrease base of support (BOS) and move COM further from BOS
To determine the stiffness of a tissue from its stress-strain curve, I would
calculate the slope in the linear (elastic) portion of the curve
Which of the following is not a primary component of connective tissue?
GAG molecules have a negative charge. What important effect does this have on the ground substance of connective tissue?
the molecules are hydrophilic and attract water into the tissue
When a biological tissue is loaded quickly, we would expect it to respond with a _______ response than when it is loaded slowly.