Biomechanics Final Exam broski
the moment arm in a torque equation is the _______ distance between the action line of the applied force and the axis of rotation
perpendicular
the proximal radioulnar joint is an example of a ________ joint
pivot
potential energy is due to _________
position
performing a chin-up is an example of _________ work (on the way up)
positive
______ energy = m x g x h
potential
muscular strength is a function of
pre-stretch size fiber type
when one who is standing in the anatomical neutral position, rotates at the hip internally (turning thigh medially), the leg is moving around what axis?
proximal to distal
which of the following is an example of amphiarthrosis
pubic symphysis
the event during an action potential where the voltage re-stabilies
repolarization
when one who is standing in the anatomical neutral position, brings his/her knee towards their chest by moving at the hip, the femur is moving predominantly in what plane
saggital
a patient performing seated knee flexion/extension exercises is moving their leg in which plane
sagittal
functional unit of a muscle
sarcomere
muscle degeneration/wasting that occurs with age is called _______
sarcopenia
which of the following is an example of a synarthrosis
skull sutures
____ can be thought of as the magnitude of velocity
speed
mechanical property equal to force divided by cross sectional area
stress
power =
work/time
_______ is a measure of the elasticity of the material and is he slope of the linear portion of a stress-strain plot
youngs modulus
the ________ of the spinal segments dictate the available range of motion at that segment
zygopophyseal joints facet joints
change in momentum is = to ______
impulse
deposition of new bone
osteoblaslt
the _______ is the outer covering of an intervertebral disc
annulus fibrosis
which of the following is an example of a pivot joint
atlantoaxial (head/neck)
intervertebral discs are
avascular
which of the following are responsible for depositing new bone
osteoblast
the _______ of the neuron carries the electrical impulse away from the cell body and may be covered by schwann cells
axon
in order for an object to be n static equilibrium, the sum of all torques =
0
kinetic energy =
1/2mv^2
newtons _____ law is also known as the law of inertia
1st
_____ is the ratio of separation over velocity of approach of a collision between two objects
2:2
newtons _____ law states that f=ma
2nd
newtons _____ law states that for every action there is a reaction that is equal in magnitude and opposite in direction
3rd
_______ is the ratio of velocity of separation over velocity of approach of a collision between two objects
COR
the center of mass (COM) of an average adult is, on average, located where
L5S1
in this disease it is believed that motor neurons become unmyelinated
MS
formula for strain energy =
SE = 1/2Kdelta^2
the neurotransmitter released from the pre-synaptic neuron at a synapse is called
acetylcholine
which of the following is an example of an osteokinematic movement
adduction
materials that handle strain in only one direction well (ex. achilles tendon)
anisotropic
the inner spongy "matrix" layer of bone is called ________
cancellous
________ can withstand tensile and compressive forces, is extremely hydrophilic and is avascular
cartilage
which of the following is NOT a bone shape
celluloid
when on changes their body position / shape (and COM), the location of their ______ also changes
center of gravity
when applied force causes an object to translate only, we deem that force to be ________
centric
angular velocity =
change in radians/change in time
linear acceleration =
change in velocity/change in time
when moving the arm though a range of motion by "bending" at the elbow, the internal moment arm ___________
changes
bone is typically most resistant (tolerant) to which of the following
compression
_______ muscular contractions are a good example of positive work
concentric
shape of distal femur is
convex
the dense outer layer of bone is called
cortical
skeletal muscle fibers are
cylindrical multi-nucleated long
crystallized bone mineral that accounts for ~43% of bone content
hydroxytaptite
which of the following individuals had no input into biomechanics
da vinci newton Wolff
the SI unit for angular acceleration is _______
degrees/s^2
vectors have magnitude and ______
direction
when an applied force causes an object to rotate only, we deem that force to be ______
eccentric
the _____ pathway of the nervous system actuates motor movements
efferent
T/F: a fixed point positioned at the far end of a golf club moves the same linear velocity as a fixed point at the middle of the club
false
T/F: angular velocity is measures in m/s/s
false
T/F: increased muscular strength is primarily caused by hyperplasia
false
T/F: the moment arm is the parallel distance from the point of force application to the center of rotation of a joint
false
T/F: when a concave segment moves upon a fixed convex segment, the roll and glide occur in the opposite direction
false
the type of cartilage located within menisci
fibrocartilage
this type of cartilage is located within the vertebral discs
fibrocartilage
pressure is equal to the _______ applied by an object divided by the
force surface area
torque =
force x radius
pressure =
force/area
which of the following is an example of an arthrokinematic joint movement
glide
great example of 1st class lever system
head on neck
as velocity of contraction decreases, muscle force potential _________
increases
characteristic of a tissue in which the same material properties apply regardless of direction loaded
isotropic
materias that handle strain the same regardless of loading (direction) (ex. ligaments)
isotropic
si unit for work
joule
moment arm impacts the ____ of a system
mechanical advantage
when one who is standing in the anotomical neutral position, flexes their hip joint, motion occurs at what axis?
medial-latera
KE is due to ______
motion
a single alpha motor neuron and all of the muscle intevates
motor unit
which of the following is NOT a trunk flexor muscle
multifidus
__________ are proproceptors responsible for signaling changes in muscle fiber rate of contraction
muscle spindle
propriocepter responsible for signaling changes in rate of muscular contraciton
muscle spindle
lowering oneself down from the top of a pull-up exercise is an example of ________ work
negative
scalars have magnitude and ________
nothing else
example of a second class lever system
talocrural (ankle) joint in sagittal plane
with respect to angular kinematics, ________ acceleration is defined as linear acceleration directed tangential to the object rotating angularly
tangential
bone is typically least resistant to which of the following
tension
in order to change the impulse an object experiences, one can most readily impact which component during sports or activities of daily living
time
T/F: joint moment = moment = torque
true
T/F: muscular strength is directly proportional to the physiological cross-sectional area (PCSA) of a muscle unit
true
T/F: potential energy is the ability of a system to perform work based on position
true
a fixed position at the far end of a golf club, moves at a faster linear velocity than at a fixed point
true
angular velocity is measured in m/s/s
true
isotropic materials respond to stress equally, regardless of direction of force application
true
potential energy is the ability of a system to perform work based on position
true
skeletal muscle transforms chemical energy into mechanical energy
true
the moment arm is the perpendicular distance from the point to the center of rotation of a joint
true
the largest stress a material can sustain before it breaks is deemed the ________
ultimate stress
_________ accounts for ~25% of the content of bone
water
SI unit for power
watt
the unit of joules/second is also known as a _________
watt