Lecture 7: Musculoskeletal Development Across the Lifespan

Question 1

Skeletal , muscle tissue, limb buds = what week

Answer 1

5

Question 2

Limb movements = what week

Answer 2

8th

Question 3

Kick legs, turning feet, bending wrist, turn heading head, opening mouth, and swallowing = what month

Answer 3

3rd month

Question 4

Thumb sucking = what month

Answer 4

4th

Question 5

Infancy has what type fibers primarily

Answer 5

Type 1 (slow twitch)

Question 6

What is sarcopenia?

Answer 6

Decresed muscle mass

note infants have this

Question 7

How much does muscle mass decrease after age 30

Answer 7

3-8%

note this number increases after 60

Neurmuscular alternations include a decrease in the nervous firing rate to muscle, the number of motor neurons, and the regenerative abilities of the nervous tissue

Question 8

Connective tissue = dense ordinary connective tissue: regular or irregular

Do tendons have a regular or iregular arrangement?

Connective tissue that surrounds bones, muscles, heart is regular or iregular?

Answer 8

1 = regular
2 = irregular

Question 9

Where is cartilage primarily found?

Answer 9

Articulating joints

Question 10

Clavicle, manduble, and facial, cranial flat bones (irregular bones primarily) ossify how?

Answer 10

Intramembranous ossification

Question 11

Deposition of bone on a cartilaginous model, limb bud, or outgrowth

Answer 11

Endochondral ossification

more long bone

Primarily ossification center that grows outward in the middle

Secondary in the ends of the bones that grow inward
* dont fully meet till ~18

Question 12

Epiphyseal plates: allow the bone to grow until adult stature is attained

Question 13

When is almost all bone growht done by?

Answer 13

18 (boys earlier than girls)

Question 14

where would you guess you see bone fractions more older or younger?

Answer 14

Older: osteoblast activity decrease and osteoclast activity increases

Children have more cartilage so can absorb force/wt more

Question 15

Result of joint mobility and the extensibility of soft tissues that cross the joint

Answer 15

Flexibility

Question 16

What is physiologic flexion?

Answer 16

Wanting to be in flexion more as a baby
* becuse they were crunched up in utero

Question 17

When do you see physiological flexion?

Answer 17

In both infants and older adults

old adults because age related changes at the cellular level compromise repair/function

Question 18

KNOW: Babies typically have more ROM because they don’t have as much ossification (all the bones havent fully come together yet) and they’re already in ltos of physiological flexion

Question 19

KNOW: Pre mature babies are bronw w/o physiological flexion (dont have to fit)

Question 20

Breech

Answer 20

coming out feet first
* not optimal for dilvery

Question 21

No children have much more DF than adults

Question 22

Infants have how many bones

adults

Answer 22

~300 (hard to tell because some havent fully ossified and others have at different times)

206

Question 23

Head bigger in babies torso smaller
* eyes don’t really change in size

Question 24

KNOW: Fontanelles are there so the skull can fit through the birth canal

Question 25

Heart takes up much more of thoracic cavity in children

Question 26

KNOW: Posture starts at physicalgical flexion and end with it starts curving around the time they start sitting ~6 months

Question 28

KNOW: variability is a crucial element of motor development * Allowing adaptability to the demands of a task and contextual aspects of the environment Essentially everyone develops differently so we need have variability in what we do and how poeple do specific movements because not everyone is the same * we all stand up and sit down a zillion different times and our body picks the patterns that are best for us also doing tasks in varying environments

Question 29

What is Sarcopena? * causes what in older adults?

Answer 29

Decreased muscle mass that leads to decerased strength * Slowing of contractile properties * muscle loss can be accelerated by disease/medications * Major cause of disability and frailty in older adults

Question 30

KNOW: ligaments and tendons affected by surronding sturcutres * Can be come stiff, lose elasticity, and decreased tensile strength Tensile strength: Tension * The maximum amount of stress a materal can withstand before breaking when it is pulled/stretched

Question 31

What muscle fibers are mo affected in muscle loss type 1 or 2

Answer 31

type 2 KNOW: muscle fibers are replaced by fat * Not due to being obese or sedentary lifestyle * Muscle loss is going to happen no matter what and the body needs to fill its gaps and uses adipose tissue

Question 32

Metabolic changes that contribute to sarcopnia: (5)

Answer 32

1) Increased insulin resistance (decerases the amount of GH in body) 2) decreased GH and insulin like GH (when osteoblasts are not being stimulated) 3) Decrease estorgen/testosterone (aids in production of GH) 4) Vitamin D deficiency 5) Increased parathyroid hormone (Increases Ca2+ which increases osteoclastic activity)

Question 33

How can sarcopenia be reversed?

Answer 33

With high-intensity progressive resistive EX * Just make sure dosing is correct (most commonly PT's underdose older individuals)

Question 34

KNOW: other causes of muscle loss * Diabetes (insulin resistance) * Metabolic syndrome (insulin resistance) * COPD - O2 exchange affected * Cancer * CHF - O2 exchange affected * Arthritits * Kidney Disease - O2 exchange affected * Stroke * Parkinson's Disease

Question 35

With older adults: bone and cartilage are decreased due to Decreased osteoblastic activity (build) * Causes decrease in bone mass/density Decreased tensile strength of bone (more susceptable to fx because of this) * More susceptible to fractures (women > men due to decreased GH/estogen) ***Long term corticosteriod use * Impair bone healing**

Question 36

KNOW: W/ age cartilage dehydrates, becomes stiffer, and thins in weightbearing areas if we dont allow the weight bearing to happen Decreased collagen production If you under dose it will not stimulate enough osteoblastic activity, and if you overdose it can blunt osteoblastic activity as well.

Question 37

KNOW: These myofibrils empty w/ age, leaving only the structure around them (looks like a honey comb) * This causes a decrease in structure You are going to have increased structural protein cross-linkages * These are those bridges that go from myofibril to myofibril * However, when you decrease the total # of overall fibers these linkages continue to grow and get longer to connect the reminaing fibers * These are not as strong or as felxibile as a muscle fiber (its stiffer) * **Same concept as osteoprosis where you're decrease the density of overall muscle and its weaker** Decreased proteoglyan size Fragmented collagen

Question 38

Age releated changes in connective tissue Cellular * decreased proliferation * Alterd control of apoptosis * Decreased response to growth factors * Altered response to loading (dont have the same amount of osteoblastic activity)

Question 39

Deeper structures = more normal collagen Disorganized collagen = more superficial collagen

Question 40

Age releated changes in connective tissue Connective tissue strucutre: * Increased stiffness * Decreased h20 content * Decreased strength * decreased cross-sectional area and volume All this stuff also happens to IV discs

Question 41

Is osteoprosis a MSK pathology? * What is it and what is it due to

Answer 41

No! its a metabolic disorder due to lack of vitamin D * Vitamin D needed to synthesize Ca2+ Increased osteoclast and decreased osteoblastic activity decreased load absorption Impaired neuromusclar function as well * Nerves not firing/regenerating as well as they were before which means they might not be innervating the msucles are well as they did before (turns into muscle problem) Preceeded by osteopenia

Question 42

4 places where fx is common in older adults

Answer 42

1) Head of femur 2) Pelvis 3) Distal radius 4) vertebrae

Question 43

Cartilage is how much water?

Answer 43

60-80%

Question 44

Cartilage: w/ age 1) decreased proliferation of chondroblasts (decreased strength / volume) 2) Altered apoptosis regulation (programmed cell death) 3) Altered response to loading 4) Increase in collagen fibers increase stiffness (less water in cartilage tissue - remember cartilage is 60-80% H2O)

Question 45

W/ age: IV discs decreased size * decreased h2O content * Can cause DDD due to decreased disc height Nucleus becomes more fibrous (decreased flexibility / elasticity) Annulus becomes less organized - more fragile to tensile strengths

Question 46

Common joint replacements TKA: * Most common * 4.2 adults over 50 have this * females > males * ~40% are 50-69 when its done THA (find percautions) * Anterior approach * Lateral approach * Posterior approach Total shoulder / reverse * reverse best for a completely fucked rotator cuff ANDDDD no signs of arthritits (normally more truamatic)

Question 47

Frality guidelines

Answer 47

Need 3/5 for frality 2/5 for pre