Week 2 Flashcards
Muscles have different
shapes and fiber arrangements
Cross section diameter
The bigger the diameter = greater force exertion
Longer muscles can…
shorten through a greater range
2 major fiber arrangements
Parallel and Pennate
Describe Parallel muscles
fibers arranged parallel to muscle
Have a greater range of movement than pennate arrangements
Parallel Muscle Categorize
Flat Fusiform Strap Radiate Sphincter or Circular
Pennate Muscles
have shorter fibers to parallel
arranged like a feather
arrangement increases the cross sectional are of the muscle so more power
Pennate Muscle Categorize
Unipennate
Bipennate
Multipennate
(if pennate is in the word, its a pennate muscle)
Muscle tissue: Skeletal Muscle has 4 Properties
Irritability or excitability
Contractility
Extensibility
Elasticity
Irritability or Excitability
property of muscle being sensitive or responsive to chemical (nerve), electrical, or mechanical stimuli
Contractility
Ability of muscle to contract and
develop tension or internal force against resistance ; when stimulated
Extensibility
Ability of muscle to be stretched beyond resting length
Elasticity
ability of muscle to return to original length after stretching
When you stimulate a muscle…
it contracts and produces force
When a muscle contracts…
one end will only move
Origin and assertion
Contraction
a muscle becomes tense due to stimulus
muscle contraction also means
muscle action
Isometric Contraction
the muscle stays the same length
joint angles remain constant
Types of Muscle contractions
Isometric
Isotonic
Isotonic
Concentric
Eccentric
Isotonic Contractions
muscle tension to cause or control movement
Passive Movement
movement without any muscle contraction
due to external force
Eccentric Contraction
muscle lengthening under tension
force from muscle is weaker than resistance
(still controlled)
Concentric Contraction
muscle shortens under tension
force from muscle is greater than resistance
Isokenetics
type of exercise using concentric/eccentric
speed or velocity is the same
Agonist Muscle
primary or prime movers
most involved muscles
Antagonist muscles
located on opposite side of joint
opposite concentric action (relax)
Stabilizers
Surround joint or body part
“fixators”
Synergist
assist in action of agonist
not prime movers
Neutralizers
prevent unwanted contractions and fluctuations
3 Cardinal planes of motion
Sagittal PLane
Frontal Plane
Transverse Plane
Sagittal plane
divides body down the middle
left and right half
Frontal Plane
divides body into anterior and posterior halves
Transverse Plane
divides body into superior and inferior halves
Axes of Rotations
Mediolateral Axis
Anteroposterior Axis
Longitudinal Axis
Mediolateral Axis
runs side to side (like frontal plane)
right angle with Sagittal plane
Anteroposterior Axis
runs front to back (like sagittal plane)
right angle with frontal plane
Longitudinal Axis
Runs up and down head
right angle with transverse plane
