Anatomical Kines #2

Skeletal muscle

muscle tissue that controls body movement

smooth muscle

muscle tissue that forms the walls of your abdominal organs, blood vessels and airways

Cardiac muscle

muscle tissue found only in your heart

Epimysium

outer layer - found beneath the fascia profunda

perimysium

middle layer - found beneath the fascia profounda

endomysium

inner layer - found beneath the fascia profunda

myofibril

cylindrical contractile organelles containing myofilaments (actin and myosin)

sarcomere - what makes it up

base unit of contraction - contains thick and thin myofilaments (actin and myosin)

parallel muscle fiber

relatively long muscle fibers and straightforward design

pennate muscle fiber

fibers run at an oblique angle to a central tendon - produces more force than parallel but less ROM, unipennate, bipennate, multipennate

concentric

shortening of muscle

eccentric

lengthening of muscle

isotonic

muscle changes length, either shortening or lengthening

movement yes - resistance fixed or variable - speed variable

isometric

length of the muscle does not change

movement no - resistance variable - speed none

isokinetic

muscle changes length, speed and velocity remain the same

movement yes - resistance variable - speed fixed

origin

the attachment to the more stationary bone

insertion

the attachment to the more mobile bone

reverse action

origin and insertion swap roles - origin is mobile and insertion is stationary

agonist

prime mover

antagonist

executes action opposite of agonist when shortens

synergist

any muscle that assists the agonist in producing main action

neutralizer

fixator - cancels our unwanted movement - necessary because an agonist does not know direction when it engages

supporter

muscles often do not function near the main action but support another part of the body in position when the main action occurs

postural muscles

designed to perform for long periods of time in semi contracted state - limited mobility and strength - will adapt to the forces you consistently apply

phasic muscles

muscles that perform movement - made to be powerful and strong for short periods - also adapt to the forces you consistently apply

length/speed relationship

speed of a muscles contraction will dictate its maximal force production - as one increases the other decreases

force/length relationship

length of a muscle, relative to its resting length during an isometric contraction, will determine the maximum force it can produce

inertia

an objects resistance to a change in its state of motion or rest

mass

quantity of matter in an object

torque

force that involves rotation of an objection around its axis

vector

force with direction and magnitude

friction

force that resists the relative motion of two surfaces

velocity

rate of change of position - speed plus direction

momentum

product of mass and velocity

gravity

force that attracts a body towards the center of the earth

newtons 1 law

inertia - object at rest stays and rest and an object in motion stays in motion unless acted on

newtons 2 law

acceleration - the force on an object is equal to its mass multiplied by its acceleration

newtons 3 law

action/reaction - for every action there is an equal and opposite reaction

linear force

all forces occur along the same line of pull - act in same or opposite directions

parallel force

aligned with each other but are either adjacent to each other or acting at different depths - can move in same or different directions

concurrent force

when two or more forces connect at a common point but pull together in one direction

resultant force

the net result of two or more different forces

first class lever - where is axis, effort,resistance

axis is in the middle, load on one side resistance on the other

2nd class lever - where is axis, effort,resistance

load is in the middle between the axis and resistance

3rd class lever - where is axis, effort,resistance

effort is in the middle between axis and resistance

center of gravity

imaginary balancing point where the weight of an object is concentrated

base of support

the part or parts of the body in contact with a supportive surface like floor or ground

line of gravity

imaginary plumb line that runs straight through your head, torso, and center of gravity to the ground

• stable - objects center of gravity is in its lowest position - laying supine

• unstable - when objects stability is easily disturbed by a small force and its center of gravity is elevated

• neutral - happens when an objects center of gravity its neither raised nor lowered when disturbed

equilibrium - 3 stages

principles of stability

1. the lower a body COG the greater stability

2. widening the bodys base of support in the direction of the line of force will generate greater stability

3. to maximize stability a persons line of gravity needs to pass through the base of support at the location that will provide the largest potential ROM in the direction of motion forces

4. in general a person with more mass will possess greater stability

5. the bodys most stable arrangement is when the COG of each weight bearing section is centered over the BOS

6. the more friction between a surface and the body point of contact with that surface, the more stable the body will be

• create movement

• stabilize posture

• assist with circulation of fluids

• perform thermogenesis

four functions of muscle tissue

excitability

capacity to respond to stimuli

what happens to actin and myosin during the sliding filament mechanism

myosin heads at both ends of the thick filament attach to actin and progressively pull the thin filaments toward the M-line

type 1 muscle fibers - list exercise examples

slow fibers - endurance - generate slower contraction fibers fatigue slowly

marathon running

type 2 muscle fibers - list exercise examples

fast fibers are larger and produce faster contractions - fatigue more rapidly - olympic weightlifting (snatches, cleans)

passive insufficiency - examples

happens when a bi or multi articular muscle is in a position of maximum excursion - action is inhibited because the antagonist muscle cannot lengthen sufficiently (pull hand towards you and try to make a tight fist)

active insufficiency - examples

occurs when an action is weakened or incomplete due to the excessive shortness of the multi-joint agonist - flexion of wrist and finger joints places flexor muscle in and ultra shortened position

line of pull - direction of movement
axis of rotation - located at center of joint
moment arm - perpendicular distance between muscles line of pull and axis of rotation

torque - line of pull, axis of rotation, moment arm

contractibility

ability to develop tension when stimulated

extensibility

capacity of muscle tissue to stretch without being damaged

elasticity

tendency to return to original length after being stretched