Analysis of Human Movement Ch. 1

Movement on the sagittal plane

flexion, extension

Movement on the transverse plane

rotation

Movement on the frontal plane

adduction, abduction

open-chain movement

resistance edge not touching anything (stabilized)

Closed-chain movement

stabilized and connected by something

First Class

fulcrum in middle of load and force

2nd Class

fulcrum on one side, load in the middle, force on the other end

3rd Class

fulcrum is attached to the lever

What are bones made up of

Calcium and Collagen

cortical bones

provide more rigid support have greater mineral content than collagens

Cancelous bone

found at the end of long bones and absorb compressive loads

Articular cartilage

dense connective tissue that absorbs connective forces

Osteoarthritis

degeneration of articular cartilage

Ligament

connect bones to bones

Tendons

connect muscle to bone

Joint capsule

forms a dense fibrous sleeve around a moving joint, providing stability and lubricating joint with synovial fluid

Aponeurosis

broad fibrous insertion that often connects adjacent muscles

Myofibers

individual muscle fibers

fascicle

group of muscle fibers

endomysium

wraps individual muscle fibers with connective tissue and contains capillaries and nerve fibers that innervate and supply individual muscle fibers

Perimysium

groups of muscle fibers are wrapped in a connective tissue sleeve

Epimysium

Connective tissue sleeve that surrounds groups of fascicles, forming the entire muscle and converging at the end of the muscle to form tendons

myofibrils

each muscle fiber is made up of hundreds of these long cylindrical strands of contractile programs

sarcomere

contractile units of a muscle and contain two types of protein filaments (thick and thin)

actin

thin protein thilament

myosin

thick protein filaments

motor unit

consists of a single motor neuron and all the muscle fibers it innervates (controls)

Strength of muscle at different positions

mid-range= strongest

shortened/at full range of motion= middle

lengthened/at rest- worst

A single muscle is made up of…

many individual motor units that send seperate electrical signals to groups of sarcomeres

tetonic muscle contraction

sum of many motor units firing

fascia

a covering that goes over top of your muscles

hypotonia

loss of nerve innervvation to a muscle (less tone)

hypertonia

unregulated contractile signals coming from the CNS(too much tone)

muscle spindles

elongated structures withing muscle fibers that sends signals of change in muscle length to protect from injury

stretch reflex

activates a muscle to contract if overstretched

slow-twitch fibers

low force sustained over a long periods of time and are resistant to fatigue

fast-twitch fibers

generate powerful contraction for intense focused movement

motor patters

learned patterns of motion, sending motor signals simutaneously to different parts of body for integrated, coordinated, functional movement

agonist

generates the most force to produce the movement

antagonist

muscles that oppose the action of the primary muscle contracting

stabilizers

muscles that stabilize the origin of the agonist

synergists

muscles that assist the agonist

forced couple

when two or more muscles or forces act in opposite directions to produce the same movement or stabilize a joint

Isometric

muscle contraction without a change in muscle length/without joint movement

eccentric

muscle contraction with the muscle lengthening

concentric

muscle contraction with the muscle shortening

Passive insufficiency

when a muscle is stretched to the point it cannot lengthen any further

Active insufficiency

occurs when a muscle that crossed two or more joints cannot generate enought force because it is too shortened

Closed-pack joint position

position of joint with maximal contact between articular surfaces (knee joint)

open-pack joint position

position of less surface contact and laxity of the surrounding ligaments (shoulder)

Ball and socket joint

spherical surface of one bone fits into concave depression of another bone- most mobile joint (shoulder, hip)

Condyloid joint

oval-shaoed convex end of one bone articulating with eliptical concave basin of another- allows flexion, extension, abduction, and adduction (4 digits except thumb, toes)

Hinge joint

permits only flexion and extension around a single axis (elbow, interphalange)

Saddle Joint

both surfaces are shaped like a saddle- allows flexion, extension, abduction, adduction, limited rotation (thumb)

Plane joint

found between two flat surfaces of adjacent bones- only allows gliding movements (acromioclavicular)

Pivot joint

a single axis with one bone rotating around another (atlas/axis, radioulnar joint)

Compress

weight bearing

Distract

traction- pull the joint apart

Glide

joint surfaces move across one another

Spin

one bone spins around a stationary surface