Distal segment fixed, proximal end moves

Ex. you rise from a seated postion

your knees extend causing your hips and ankles to move as well.

The distal segment is free while the proximal

segment can remain stationary

Parallel          Oblique        Strap

fusiform        rhomboidal      triangular

unipennate    bipennate      multipennate

tend to be longer having greater ROM

tend to be shorter but are more numerous per given area.

greater strength potential but smaller ROM than paralel fibers.

Four sided, usually flat, broad attachments at ea. end

Ex. pronator quadratus in forearm

or

rhomboids in the shoulder girdle

&

gluteus maximus in hip region

flat, and fan shaped w/ fibers radiating from a narrow attachment at one end to a broad attachment to the other.

Example: Pectoralis Major

look like one side of a feather,

 series of short fibers attaching diagonally along the length of a central tendon

Ex. tibialis posterior muscle of the ankle, semimembranosus of the hip and knee

& flexor pollicis longus muscle of hand

Unipennate Muscle

looks like common feather, Fibers are oblliquely attached to both sides of central tendon

Ex. rectus femorus muscles of hip &

interossei muscle of hand

has many tendons w/ oblique fibers in btwn

Ex. deltoid and subscapularis muscle at schoulder

When the "moveable" end becomes fixed

and the origin moves toward the insertion

Spindle shape

Wider in the middle and tapers at both ends

where it attaches to tendons

The only tissue in the body that has

irritability

contractility

extensibility

elasticity

The length of a muscle when itis unstimulated,

no force or stress placed on it

Ability to shorten or contract when it

recieves adequate stimulation

Ability of a muscle to strech or lenthen

when force is applied

Ability to recoil or return to normal resting length

when the stretching or shortening

force is removed

Elasticity

Ex. saltwater taffy has extensibility, but not elasticity

Tension

passive tension- involves noncontractile units of muscle

              "like streching a rubber band"

active tension- comes from contractile units of a muscle

       "like- releasing one end of a streched rubber band"

Slight tension present in a muscleat all times

Even when muscle is resting

The distance from

Maximum elongation

to

Maximum shortening

Excursion

Contracted       excursion

_______3"------------------

Normal resting

_______________6"

Stretched

______________________9"

When a muscle reaches a point where

it can not shorten any farther

Active insufficiency

Occurs to the agonist (the muscle contracting)

When a muscle cannot elongate

any further without damaging its fibers

Passive insufficiency

Occurs to the antagonist

( the muscle that is relaxed and on the opposite side of the joint from the agonist)

When a muscle contracts

producing force without

changing the muscle length

Partial opening and closing of the hand

occurs due to passive insufficiency

Tenodesis

Ex. When forearm is resting on the table in a pronated position, relax and wrist drops into flexion, the fingers tend to extend passively. When forearm is suppinated

your wrist relaxes into wrist extension fingers will ten to clse.

A contraction that shortens the length of

while overcoming some resistance

A contraction that lengthens the muscle

slowly against gravity

Eccentric

Slow force, Decelerating