Kinesiology Test Review Flashcards
Gravity is the most _____ _____.
Ubiquitous force
Scalar quantities
speed, mass
indicates magnitude only
Vector quantities
Velocity, weight
indicates magnitude and direction
Rotational work
T X angular displacement
Mechanical Advantage
A ratio of the effort arm to the resistance arm
MA = EA/RA
A mechanical advantage of <1 reflects a relative disadvantage
Levers are meant to…
multiply force to gain mechanical advantage or to multiply speed and range of motion
Impulse momentum theorem
Force over a little period of time=
Greater impact
Impulse momentum theorem
Force spread over a large period of time=
Less impact
Equilibrium
ability to maintain balance
how many bones are in the body?
206 bones
How many vertebrae are there?
33 total
Joint stability is inversely related to joint…
ROM, Mobility, Flexibility
The more ROM, Mobility, and flexibility a joint has…
the less stable it is
Frontal plane movement
anterioposterior axis of rotation
saggital plane movement
transverse rotational axis
horizontal plane movement
longitudinal axis
Porperties of muscle tissue
extensible elastic irritable contractile adaptable
Flat muscle
Parallel muscle
thin, broad, originating from a broad, fibrous, sheet-like aponeurosis that allows them to spread their force over a large area.
Example: rectus abdominus and external oblique
Fusiform muscle
parallel
spindle shaped with a central belly that tapers to the tendons on each end
Example: brachialis and brachioradialis
Strap Muscle
parallel
more uniform in diameter with all of their fibers arranged in a long parallel manner.
example: Sartorius
Radiate muscle
parallel
triangular, fan-shaped, or convergent. Combined fiber arrangement of flat and fusiform muscle.
Example: pectoralis major and trapezius
Unipennate muscle fibers
run obliquely in relation to their tendon on only one side
Example: biceps femoris and tibialis post
Bipennate muscle fibers
fibers run obliquely on both sides of a central tendon
Example: rectus femoris and hallucis longus
Multipennate muscle fibers
have several tendons with fibers arranged obliquely
Example: deltoid
Which pennate muscle fibers produce the strongest contraction?
Bipennate and unipennate
Smallest functional unit within a muscle fiber?
sarcomere
Motor unit
consists of alpha motor neuron and the associated muscle fibers that it intervates.
What determines the muscle fiber type, characteristics, function, and involvement in exercise?
The motor unit
Neuromuscular Junction NMJ
The interface between the nerve and the skeletal muscle
Maximal strength and power increase of agonist muscles generally result from an increase in…
recruitment, rate of firing, synchronization of firing, or a combination of these factors
Size principle
Motor units are recruited in order according to their recruitment threshold and firing rates
Selective Recruitment
Lower threshold motor units are inhibited to allow preferential recruitment for fast twitch motor units. Occur in certain circumstances
Cross innervation
one muscle fiber can be innervated by two neurons
bilateral deficit
force produced when both limbs are contracting together is less than the sum of the forces they produce when contracting unilaterally
Example: cycling
Concontraction
Muscle activity of the antagonist during agonist movements.
Mechanism to increase joint stability
twitch
brief rapid contraction of a muscle
tetanus
multiple electrical impulses must be sent in sequence until it increases to tetanus where tension in the muscle is sustained
What dictates muscle fiber types?
Neuron
Rate coding
increasing or decreasing the frequency of motor neuron activity
recruitment patterns
motor unit recruitment patterns calls upon different numbers or motor units within the muscle
Size order principle of motor unit recruitment
generally slow twitch fibers are recruited first due to their lower activation threshold than fast twitch motor units
Pre-movement Silence
A positive adaptation seen in trained individuals, wherein just prior to explosive movement, all neuronal imput ceases. This readies the motor units so they can be fired simultaneously
