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Kinesiology Exam 1 > Muscle Function pt2 > Flashcards

Muscle Function pt2 Flashcards

1
Q

active tension

A

tension developed by the contractile elements of the muscle

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2
Q

what is active tension initiated by

A

cross bridge formation and movement of the actin and myosin

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3
Q

passive tension

A

tension developed in the passive non-contractile components of the muscle

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4
Q

where is passive tension developed

A

the parallel elastic components of the muscle

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5
Q

what is w/in the connective tissue that surrounds the muscle

A

titin (protein)

nerves and vessels

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6
Q

what is the length-tension relationship

A

there is a direct relationship b/w tension development in a muscle and length of a muscle

there is an optimal length at which a muscle is capable of developing maximal tension

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7
Q

optimal length

A

where a muscle is capable of developing maximal tension

optimal length is close to what is called “resting length”

1.2 times resting length

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8
Q

when do muscles develop maximal tension

A

at optimal length

b/w the actin and myosin are positioned for the maximum number of cross bridges

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9
Q

what happens when a muscle is shortened or lengthened beyond optimal length

A

force producing capabilities are decreased

too long –> minimal cross bridging, no tension generated

too short –> unable to shorten anymore, no cross bridging, no tension

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10
Q

what happens at optimal length

A

maximal number of cross bridges

maximal shortening

maximal tension (optimal tension)

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11
Q

what position will the body tend to put the muscles at when maximal tension is required

A

optimal length

optimal length = optimal tension

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12
Q

why is positioning of our patients while they perform their exercises important?

A

the position we place our patients in can alter the tension-length relationship

we allow the patient’s muscle to be @ an advantage to produce the optimal amount of tension

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13
Q

single joint muscles

A

muscles that cross only one joint

ex: brachialis

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14
Q

multi joint muscles

A

muscles that cross two or more joints

more efficient than 1 joint muscles

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15
Q

why are multi-joint muscles more efficient than single joint muscles

A

they can maintain an optimal length tension relationship throughout the range of motion

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16
Q

where do muscle insufficiencies primarily occur

A

multi-joint muscles

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17
Q

2 types of muscle insufficiencies

A

active insufficiency and passive insufficiency

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18
Q

2 types of active insufficiency

A

too long

too short

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19
Q

active insufficiency

A

TENSION

the diminished ability of a muscle to produce or maintain active tension

occurs when a muscle is too short or too long

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20
Q

too long active insufficiency

A

the muscle is elongated to a point at which there is no overlap b/w the actin and myosin

no cross bridges

no cross bridges = no active tension

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21
Q

example of too long active insufficiency

A

hip flexion and knee extension

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22
Q

too short active insufficiency

A

the muscle has shortened to a point at which no further sliding of the filaments can take place

cross bridges are maximally overlapped

no sliding –> no active tension

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23
Q

when does too short active insufficiency occur

A

when the full AROM is attempted simultaneously at all joints by the muscle

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24
Q

too short active insufficiency example

A

hip extension and knee flexion

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25
Q

what positions do you avoid with patients

A

every muscle has 2 positions of active insufficiency

these positions are those to avoid

26
Q

passive insufficiency

A

ROM

occurs when a muscle is of insufficient length to permit completion of the full ROM available @ the joints crossed by the muscle

the muscle isn’t long enough to provide full ROM @ all joints the muscle crosses

27
Q

what happens when the muscle develops passive tension

A

may be enough to pull the bony lever in the direction of passive pull

tendinosis

28
Q

what is tendinosis

A

muscle creates enough passive tension to pull the bony lever

29
Q

example of passive insufficiency

A

hamstrings

in the supine position, when the hip is being pushed into flexion, there is a point the knee will begin to flex d/t the amount of passive tension

30
Q

active v. passive insufficiency

A

while both are related to the length of the muscle…

passive involves elastic or passive elements

active involves the contractile or active elements

31
Q

a position of passive insufficiency will…

A

always be one of the positions of active insufficiencies

when the muscle is too long

32
Q

types of muscle action

A

isometric contraction

isotonic contraction

33
Q

isometric contraction

A

constant length (length never changes)

the distal and proximal attachments are fixed (distance =0)

shortening occurs at the myofibril level (visible length remains unchanged)

no mechanical work is performed

34
Q

isotonic contraction

A

constant tension

tension never changed

35
Q

2 types of isotonic contraction

A

concentric and eccentric

36
Q

concentric contraction

A

shortening contraction

origin and insertion move closer together

positive work is being done by the muscle

37
Q

eccentric contraction

A

lengthening contraction

origin and insertion move apart

muscle lengthens while it maintains tension

negative work is done

tends to be about control

38
Q

when does eccentric contraction occur

A

when the forced that the muscle generates is insufficient to offset an opposing force on a lever or the resisting force of gravity

39
Q

force production according to contraction type

A

eccentric contraction will produce the most tension

concentric contraction produces the least tension

40
Q

reverse muscle action

A

occurs when the muscles distal attachment is fixed and the proximal is free

proximal bony component is pulled towards the distal bony component

origin moves towards the insertion

can occur in a concentric or eccentric contraction

41
Q

agonist muscle

A

muscle that is responsible for producing a desired motion at a joint

42
Q

types of agonist muscles

A

prime movers

secondary mover

43
Q

prime movers

A

agonists

the muscle that plays the greatest role in completing the movement

44
Q

secondary mover

A

agonist

does not consistently work in completing the movement but may be recruited to assist

45
Q

antagonist

A

the muscle that has an action directly opposed to that of the agonist

46
Q

synergist

A

refers to those muscles that help the agonist to perform a desired action

may assist the agonist directly or indirectly

47
Q

how does a synergist directly assist the agonist

A

helping to perform the desired action

48
Q

how does a synergist indirectly assist the agonist

A

stabilizing a part or by preventing an undesired action

49
Q

types of synergists

A

conjoint synergy

neutralizing synergy

stabilizing synergy or co-contraction

50
Q

conjoint synergy

A

when 2 or more muscles act together to produce a movement that neither muscle could do alone

51
Q

example of conjoint synergy

A

radial deviation

flexor carpi radialis and extensor carpi radialis longus

there is no specific muscle or muscle group that performs radial deviation

52
Q

neutralizing synergy

A

when a 2 joint muscle contracts, there may be an undesired motion at one of the joints

so another muscle will contract to “neutralize” that undesired motion

53
Q

example of neutralizing synergy

A

finger flexion

during finer flexion, wrist extensors neutralize the finger flexion

they prevent the wrist from flexion to preserve the tension-length relationship

if the wrist were to flex, there would be active insufficiency and we wouldn’t be able to produce as much tension

54
Q

stabilizing synergy or co-contraction

A

the contraction of agonists and antagonists of a proximal joint to allow

1) highly coordinated movements

OR

2) forceful contraction of a more distal joint

55
Q

example of stabilizing synergy or co-contraction

A

finger flexion

elbow flexors and extensors stabilize the elbow while we flex our fingers to produce more force

proximal stability to produce force distally

56
Q

stabalizing or co-contraction involves

A

an agonist and antagonist

57
Q

neutralizing synergy involves

A

an agonist and some other muscle group

58
Q

spurt muscles

A

a muscle whose proximal attachment (origin) is far from the joint axis

insertion is close tot he axis

results in large ROM

59
Q

what happens when the insertion is close to the axis

A

has a large rotary or mobility component

60
Q

shunt muscles

A

a muscle whose proximal attachment (origin) is close to the joint axis

insertion is far from the joint axis

ex: brachioradialis during elbow flexion

61
Q

what happens when insertion is far from the joint axis

A

has a large translatory or stability component

62
Q

shunt v. spurt

A

shunt –> stability

spurt –> mobility

Kinesiology Exam 1 (9 decks)

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