Biomechanics

Front 1

cells that create bone

Back 1

osteoblasts

Front 2

bone cells

Back 2

osteocytes

Front 3

cells that reabsorb bone

Back 3

osteoclasts

Front 4

what does exercise stimulate in bones

Back 4

osteoclasts to increase bone formation

Front 5

type of bone near ends and type at shaft

Back 5

spongy/trabecular at ends and cortical/compact at shaft

Front 6

whats the last bone to stop growing

Back 6

clavicle

Front 7

anisotropic

Back 7

response of tiss depends on direction of load application, bone is really strong in compression but sucks with sheer/side force.

Front 8

what is both anisotropic and viscoelastic

Back 8

bone (response of tissue depends on direction of load application b/c it's strong in compression but stucks with sheer force

Front 9

is bone stronger when you load it quickly/short duration or with long duration?

Back 9

it's stronger when yo load it quickly and breaks more with increased duration

Front 10

stress vs strain

Back 10

stress =load

strain=how much it changes under that load/stress

Front 11

how much can bone strain till it fractures/breaks/begins to tear/degrade?

Back 11

up to 3 % strain (which is deformation in response to stress)

Front 12

explain wolff's law

Back 12

exercise stims bone growth and lack of exercise causes weakness of bone. this is b/c as stress decreases with disuse, immobilization or microgravity, there's a resorption response due to osteoclasts dominating causing weakness.
with increased stress from weight bearing exercise, three is a deposition response b/c osteoblasts dominate.

Front 13

are long bones stronger with compression or tension

Back 13

compression

Front 14

what's it called when a little piece of bone is ripped away by muscle/tendon at attmt site

Back 14

avulsion fracture

Front 15

why should you back off your 3rd week of training

Back 15

b/c of bone remodelling

Front 16

how can tendon aid jnt stability

Back 16

muscle contraction

Front 17

what has less stability, loose packed or closed packed?

Back 17

loose packed has less stability

Front 18

viscoelasticity

Back 18

rate and duration of loading impacts strength and behavior

Front 19

is connective tissue stiffer or weaker when you deform it quickly vs longer duration

Back 19

it's stiffer with quick deformation and more stretchy with duration b/c lig's are more crimped inrelaxed state and more straight in contracted state.

Front 20

what would happen if there were no muscle activation with joints

Back 20

yo'd blow your joints every time b/c lig's like ACL for example can withstand only 1000 newtons

Front 21

are you more likely to tear your ligament or break off part of the attmt point when you are
YOUNG and why

Back 21

break off part of the attmt point b/c when you're younger, your ligaments are stronger than attmt points but it's opposite as you grow older, you're attmt points become stronger than your ligs

Front 22

when your older are you more likely to tear your ligament or break off part of your attmt point and why

Back 22

tear your ligament b/c as you age your attmt point becomes stronger than thte lig and i'ts opposite when you're younger.

Front 23

5 functions of the skeleton

Back 23

leverage, support,(these 2 are critically important for mvt), protection, storage (Ca+, and phosphorous), blood-cell formation.

Front 24

to bones get bigger or smaller as you go inferior/distal

Back 24

bigger

Front 25

what do bones protect

Back 25

brain and internal organs

Front 26

what does bone store

Back 26

fat and minerals

Front 27

what gives bone it's elastic property

Back 27

collagen

Front 28

what gives bone it's elastic property

Back 28

collagen

Front 29

what gives bone it's elastic property

Back 29

collagen

Front 30

what gives bone it's elastic property

Back 30

collagen

Front 31

what are stress fractures

Back 31

happens when resorption weakens bone and deposition happens too slow. can result from repetitive muscle forces pulling on bone or muscle fatigue can lead to reduced shock absorption.
this accounts for 10% of injuries to athletes!

Front 32

osteokinematics vs arthrokinematics, define both

Back 32

osteo-joint motions like flexion and extension, main motions

arthro-accessory motions like roll, slide glide. these allow for osteokinematics
-improving arthro will allow ostea to happen

Front 33

loose packed vs. closed packed position: which is more stable, which has greatest injury potential, which has most contact, which has greatest volume, least friction? which is the position of choice if effusion is present

Back 33

closed=maximum contact, very stable, ligaments are tense, greater injury potential

loose: less contact, less friction, greatest volume, position of choice if effusion is present

Front 34

examples of fibrocartilage and examples of articular cartilage

Back 34

fibrocart: meniscus, articular discs, intervertebral discs, TMJ
Articular cart: aka hyaline covers joint ends

Front 35

what kind of behavior does cartilage produce-explainit

Back 35

viscoelastic: based on RATE of loading. Rapid rate -elastic response but slow rate =plastic response

Front 36

explain the joint degeneration theory

Back 36

It's a circular pattern.
if there's increased load to art. cart then there's inc load to bone leading to subchondral bone injury leading to bone healing and increased stiffness (wolff's law). leading back to more increased load to art cartilage (hyaline)
bone remodiling causes cartilage to have more load to bear.

Front 37

iritability of muscles

Back 37

ability to respond to stimulation

Front 38

what are teh 2 main fiber organizations

Back 38

fusiform and penniform

Front 39

give the three types of penniform fiber organization and an e.g. of each also is PCS less than, equal to or greather than ACS

Back 39

unipennate=semimembranosus
bipennnate=gastroc
multipennate=deltoid
PCS>ACS

Front 40

e.g. of fusiform muscle

Back 40

sartorius, biceps brachii, brachialis

Front 41

as you go from longitudinal/fuisiform, to unipennate to bipennate to multipennate what is teh general trend with respect to change in lengtrh and change in force

Back 41

as go from fusiform to multipennate, you get less change in length but incrased force production and vice versa if you go backwards

Front 42

define moto unit

Back 42

group of muscle innervated by the same motor neuron

Front 43

what color are slow twitch oxidative fibers compared with fast twitch glycolytic fibers

Back 43

red vs white

Front 44

which has a bigger motor unit type I or type II fibers and what does that mean dealing with force and duration

Back 44

type II have much bigger motor unit,k meaning number of fibers innervated is much larger so you'll get more muscle force off that motor unit
Type I on the other hand are much smaller so less force output but also much longer duration

Front 45

what is the recruitment order (size principle) of the three muscle fiber types from first to last

Back 45

ST, FOG, FT

Front 46

though the motor unit recruitment order/size principle goes ST first, then FOG, then FT, what happens with E-stim

Back 46

it goes backwards so FT,FOG and then ST, workin opposite of what we naturally do, has potential in theory but would be difficult to coordinate

Front 47

plyometrics

Back 47

conditioning protocol that utilizes pre stretching
e.g. single leg bounds, depth jumps, stair hopping

Front 48

what are the 3 mechanical components of muscle. say if they are active or passive. also what they include and what their main function is

Back 48

1.contractile- active, includes actin and myosin, converts stimulation into force
2. PEC- parallel elastic-passive, allows muscle to be stretched. is assd with fascia surrounding muscle and includes titin stuff or at z-lines
3. series elastic- passive, transfers muscle force to bone, might be tendons (think of rubber band lengthening b/c it stores energy the same way as tendons do. before the force dvpt, teh elastic elements stretch a little and that helps provide some of the force.

Front 49

while bringing your arm from elbow extension to flexion, where is the rotary force the greatest, where is the parallel force the greatest?

Back 49

rotary force is the greatest at midragne or 90 degrees. parallel force is the greatest at full extension.

Front 50

why might midrange be safest for mm testing

Back 50

b/c not as much bone on bone compressoin forces

Front 51

why is prestretching prior to active muscle contraction create more tension?

Back 51

b/c there is elastic energy storage, it adds passive tension to the muscle likea rubber band

Front 52

why is prestretching prior to active muscle contraction create more tension?

Back 52

b/c there is elastic energy storage, it adds passive tension to the muscle likea rubber band

Front 53

active insufficiency vs passive insufficiency

Back 53

passive insufficiency is when you have multi joint muscle STRETCHING which will not allow ful ROM at each joint crossed.

active insufficiency is when you have a multi join muscle UNDER ACTIVE TENSION that can't produce full ROM at each joint crossed

Front 54

what is mechanical advantage

Back 54

describes the potential of the leverage system. MA=Force arm/ resistance arm- levers in the body have a poor MA