Muscular System Chapter 5
Prime Mover
Same as the agonist
Oblique muscle fibers
Shorter, >fibers, >strength
Tone
Slight tension that is present at all times
Neutralizer
contracts to prevent the unwanted motion
Closed kinetic chain
distal-fixed proximal-moves Bench press Sit-ups The upper extremity when one is doing push-ups The upper extremity when one is supported on crutches The lower extremities when one is performing wall slides
Open kinetic chain
distal-free moving proximal-fixed free weights The upper extremity when one is walking and carrying a book bag. The lower extremities when one is swinging from an overhead bar The lower extremity being used to kick a ball
Excursion
distance from max elongation to max shortening
Bipennate muscles
feather central tendon-rectus femoris of the hip
Triangular muscles
flat fan shaped- pectoralis major
Tension
force built up w/ in a muscle when stretch build up tension active tension release
Fusiform muscle
spindle-biceps
Rhomboidal muscle
4 sided flat w/ broad attachments
Eccentric
-Lengthening contraction -Insertion moves away from origin -Isotonic contraction -Muscle contraction slows the pull of gravity on the body segement
Tenodesis
-Passive insufficiency of the finger extensors occurs when the wrist is flexed causing the fingers to extend. -Passive insufficiency of the finger flexors occurs when the wrist is extended causing the fingers to flex.
Concentric
-Shortening contraction -Insertion moves toward origin -Isotonic contraction -Muscle contraction moves the body segment against gravity
Passive insufficiency
-occurs when a muscle cannot be elongated any farther without damage to its fibers -muscle is suppose to relax -ROM
Active insufficiency
-the point when a muscle cannot shorten any further -wrist flexion
Assisting mover
A muscle that is not as effective but does assist in providing that motion is
Extensibility
Ability to be stretched beyond normal resting length
Contractility
Ability to produce tension/shorten
Elasticity
Ability to return to normal length
The sternocleidomastoid muscle typically flexes the head and neck. The mastoid process (on the head) is the insertion and the sternum and clavicle are the origin. Is the origin moving toward the insertion, or is the insertion moving toward the origin during flexion of the head and neck?
Insertion moving toward the origin
What uses the most muscle tissue?
Lengthening
Origin
More Stable. Closer to the trunk.
Insertion
More moveable part. More Distal.
Muscles have origins and insertions. Which is generally proximal?
Origin
When you have worked hard and are short of breath, the sternocleidomastoid helps you to take deeper breaths by lifting the chest. In this case, is the origin moving toward the insertion, or is the insertion moving toward the origin?
Origin is moving toward the insertion
Reversal of muscle action
When origin moves toward insertion.
Agonist
a muscle or group that causes the motion
Stabilizer
a muscle or muscle group that supports or makes firm a part and allows the agonist to work more efficiently.
Antagonist
a muscle that performs the opposite motion of the agonist
Synergist
a muscle that works with one or more other muscles to enhance a particular motion.
Irritable
ability to respond to a stimulus from nerve or electric stimulus.
Strap muscles
long, thin, fibers run entire length of muscle
Parallel muscle fibers
longer, >ROM
Multipennate muscles
many tendons w/ oblique fibers deltoid
Unipennate muscles
one sided feather- flexor polis longus