Ch.6 Flashcards
Condition occurring when a joint muscle cannot SHORTEN enough to cause full range of motion at both joints it crosses at the
same time
Active insufficiency
Role played by a muscle acting to cause a movement
Agonist
Role played by a muscle acting to slow or stop a movement
Antagonist
Describing a contraction involving shortening of a muscle
Concentric
Muscle property enabling tension development by stimulated muscle fibers
Contractile component
Describing a contraction involving lengthening of a muscle
Eccentric
Time between the arrival of muscle stimulus and tension development by the muscle
Electromechanical delay
A fiber that reaches peak tension relatively quickly
Fast twitch fiber
Describing a contraction involving no change in muscle length
Isometric
A single motor neuron and all fibers it innervates
Motor unit
Electric current or voltage produced by a muscle developing tension
Myoelectirc activity
Role played by a muscle acting to eliminate an unwanted action
produced by an agonist
Neutralizer
Passive elastic property of muscle derived from the muscle
membranes
Parallel elastic component
Pattern of fibers within a muscle in which the fibers are roughly
parallel to the longitudinal axis of the muscle
Parallel fiber arrangement
Inability of a two-joint muscle to STRETCH enough to allow full
range of motion at both joints at the same time
Passive insufficiency
Pattern of fibers within a muscle with short fibers attaching to
one or more tendons
Pennate fiber arrangement
Passive elastic property of muscle derived from the tendons
Series elastic component
A fiber that reaches peak tension relatively slowly
Slow twitch fiber
Role played by a muscle acting to stabilize a body part against
some other force
Stabilizer
Eccentric contraction followed immediately by concentric
contraction
Stretch shortening cycle
Building in an additive fashion
Summation
State of muscle producing sustained maximal tension resulting
from repetitive stimulation
Tetanus
Having the ability to stretch or shorten over time
Viscoelastic
What tissue is able to actively develop tension?
Muscle tissue
Ability to be stretched or increase in length
Extensibility
Ability to return to normal resting length following a stretch
Elasticity
Ability to respond to a stimulus
Irritability
The contractile component of muscle function
Ability to develop tension
FV: When resistance/force is negligible, muscle contracts with…
Maximal velocity
FV: As the load increases, concentric contraction slows to __ at isometric max
Zero
The elasticity of
human skeletal
muscle is believed
to be due primarily
to the…
Series elastic component
A single muscle cell that is specialized to contract and generate force
Muscle fiber
What surrounds a muscle fiber?
Sarcolemma
An action potential does not directly excite muscle fibers, but does
so through chemical processes
All or None Principle
ANP: If another action potential reaches the muscle fibers before they
relax, then the muscle fibers contract harder
temporal summation or increased firing
frequency or firing rate
Motor units are recruited in an orderly process from smallest to largest
Size Principle
Force output is changed by either:
Increasing the firing frequency
Activating more motor units
If lifting heavy weight what twitch fiber is used?
BOTH OF THEM
FV: Isometrically, Force and velocity have __ relationship
No
Increases as tension increases in the muscle fibers
Angle of pennation
FV: Concentrically, Force and velocity have __ relationship
Inverse
FV: Eccentrically, Force and velocity have __ relationship
Direct (both increase or decrease)
Which muscle action can produce the most force?
Eccentric
The magnitude of the force generated by muscle is related to…(Ms,sM)
-the velocity of muscle shortening
-the length of muscle when it is stimulated
Devices that detect signals
Transducers
