Immobilization Syndrome

Question 1

effects of immobility

Answer 1

• weakness, atrophy, poor endurance
• postural hypotension
• dvt
• immobilization osteoporosis

Question 2

main types of adverse effectts in msk

Answer 2

• muscle atrophy and weakness
• joint contracture
• immobilization osteoporosis

Question 3

hallmark of muscle atrophy

Answer 3

• decrease in muscle fiber size
• reduced muscle mass
• lmn lesion: regional
• muscle disease: proximal and antigravity muscles

Question 4

changes in sarcomere number

Answer 4

• shortened position: reduced

- elongated position: sarcomeres in series is increase and sarcomeres in parallel is reduced

Question 5

muscle fiber changes

Answer 5

• atrophy of fibers type 1 and 2a
• prevention: gravity loading muscles for 10 hours per day
• reduced collagen synthesis
• titin

Question 6

decreased growth factor release

Answer 6

• dec serum ck and fibroblast growth factor
• prevention: resistance exercise during bedrest
• myostatin inhibits muscle synthesis (inc in bedrest)

Question 7

5 mechanisms by which disuse atrophy happens

Answer 7

• alteration of metabolism and muscle cell homeostasis
• changes in sarcomere number
• muscle fiber changes
• decreased growth factor release
• inc protein breakdown

Question 8

t//f loss of strength is more prominent in lower limbs than upper limbs

Answer 8

true

Question 9

major contributors of loss of strength

Answer 9

• reduced myofibril number per fiber volume
• reduced size/ number of mitochondria/ muscle fiber nuclei
• reduced sarcomeres in parallel

Question 10

causes of reduced indurance

Answer 10

• reduced atp and glycogen storage sites
• rapid depletion of atp and glycogen
• reduced muscle protein synthesis and oxidative enzyme function
• premature anaerobic energy production with rapid lactic acid accumulation

Question 11

ferreti et al study

Answer 11

• dec vo2 max by 16%
• dec cardiac output by 30%
• dec oxygen delivery by 40%
• dec oxidative enzyme activity by 11%

Question 12

deconditioning process

Answer 12

read

Question 13

loss of muscle mass -> reduced muscle strength and endurance ->

Answer 13

reduced:

• muscle blood flow
• rbc delivery
• oxidative enzyme activity
• o2 utilization in muscle
• decreased formation of fiber 1 and 2a

Question 14

t/f lack of adequate muscle activity has no effect on cardio

Answer 14

false

Question 15

minimum resistance exercise

Answer 15

• one a day contraction at 30-50% of maximal strength for 3-5 mins, 3x a week

Question 16

pathology in joint contractures

Answer 16

• contributory conditions + lack of joint motion

- most common factor: lack of joint motion throughout full allowable range

Question 17

types of joint contractures

Answer 17

arthrogenic, myogenic, soft tissue

Question 18

what is myogenic contracture

Answer 18

• shortening of the resting muscle length
• limits full rom
• abnormal positioning of limbs or body

Question 19

most common cause of myogenic contracture

Answer 19

• after multiple injuries
• chronic illness
• sedentary lifestyle

Question 20

natural history of myogenic contracture

Answer 20

• joint muscles involved
• ue: internal rotators and elbow flexors
• le/core: hamstrings and back muscles

Question 21

pathologic processes in arthrogenic contracture

Answer 21

• cartilage degeneration
• congenital incongruency
• synovial inflammation
• effusion
• pain
• joint immobility

Question 22

acute arthritis

Answer 22

exercise -> short term immobilization to reduce inflammation

intense dynamic exercise + ordinary activity = most effective to improve physical function

Question 23

chronic arthritis

Answer 23

short term immobilization showed increased destruction of joints and cartilage

Question 24

t/f intensive exercise is more effective than conservative exercise in arthritis

Answer 24

true

Question 25

what is soft tissue contracture

Answer 25

• cutaneous, sc, loose ct around joint
• limits movement in one plane only
• prevention: rigorous active and passive rom exercises, rest joint, compressive garmets

Question 26

management of contractures

Answer 26

• prevention
• active and passive rom exercises with sustained terminal stretch on daily basis
• mild: 5-10 min
• severe: 20-30 min
• uts = most popular heat source
• sustained stretch (2+ hrs)
• last resort: tendon lengthening

Question 27

what is disuse osteoporosis

Answer 27

• loss of ca and hydroxyproline in cancellous bone, epiphyses, metaphysis, cortical bone

Question 28

non weight bearing over several weeks can cause ___

Answer 28

trabecular and endosteal mineral bone loss in tibia

can take 1-1.5 years to return to baseline

Question 29

prevention and treatment of disuse osteoporosis

Answer 29

• isotonic exercises, weight bearing and functional training, ambulation
• tilt table

Question 30

t/f resistance exercise can increase bone mass

Answer 30

true

Question 31

prolonged bed rest increases resting heart rate by ___

Answer 31

1 beat/min every 2 days
after 3 days: 32%

(reduced stroke volume and co)

Question 32

what is orthostatic intolerance

Answer 32

• prolonged bed rest = normal orthostatic response is compromised
• cannot maintain stable bp
• falls more than 20 mmhg
• rapid hr = prevents optimal filling of rv

Question 33

s/sx of postural hypotension

Answer 33

• inc pulse rate >20 bpm
• dec systolic pressure >20 mmhg
• dec pulse pressure

Question 34

virchow’s triad

Answer 34

venous stasis, hypercoagulability, blood vessel damage

Question 35

most frequent time for dvt

Answer 35

1st week of bed rest

Question 36

venous stasis in leg is due to ___

Answer 36

dec pumping activity of calf muscles and dec orthostatic pressure

Question 37

prevention of dvt

Answer 37

• sc heparin injection (lmw heparin > sc heparin)