muscular system

Question 1

types of muscle based on Muscle fiber arrangement

Answer 1

Parallel: Usually > ROM potential
Oblique: Shorter, greater strength potential, less ROM

Question 2

types of parallel muscles

Answer 2

Strap – long & thin, fibers run entire length ( sternocleidomastoid)

Fusiform – spindle shaped, attach to tendons – not all fibers run length of muscle (biceps)

Rhomboidal- four sided and flat

Triangular – flat and fan shaped, narrow attachment at one end, broad at the other
(Pectoralis Major)

Question 3

oblique muscles

Answer 3

Unipennate – look like one side of feather,
Have central tendon, muscle fibers go to one side (Flexor Pollicis)
Bipennate – looks like whole feather
Have central tendon, muscle fibers on both sides (interosseous)
Multipennate – many fibers with oblique tendons in between (deltoid)

Question 4

Resting position

Answer 4

Resting position: Length of muscle at rest (un-stimulated or no forces)

Question 5

Irritability

Answer 5

Irritability: Muscles ability to respond to stimulus. (Not an emotional state!)

Question 6

Contractibility

Answer 6

Contractibility: Ability of muscle to contract/shorten.

Question 7

Extensibility

Answer 7

Extensibility: Ability to stretch or lengthen in response to force

Question 8

Elasticity

Answer 8

Elasticity: ability to rebound to the resting length after removal of force.

Question 9

When a person “stretches” before exercise, he/she is demonstrating which muscle tissue characteristic?

Answer 9

Extensibility

Question 10

Tension

Answer 10

Tension is the force “built up” in muscle

Question 11

Passive Tension

Answer 11

Passive Tension: tension from the “non-contractile” units of the muscle. Like stretching a rubber band

Question 12

Active tension

Answer 12

Active tension: Tension from contractile units of muscle like releasing one side of that rubberband

Question 13

tone

Answer 13

Tone: slight tension present when muscle is at rest

Question 14

Normal muscle tone

Answer 14

Normal muscle tone reflects the muscles’ state of readiness

Question 15

Abnormal muscle tone

Answer 15

Abnormal muscle tone refers to “low” or “high” (spasticity). Abnormal tone is associated with CNS disorders.
high tone ex) cerabal palsy- muscles are spastic- muscles keep firing
low tone ex) someone with a stroke (can have high or low) when a limb just hangs= low tone
ex) someone who is paralysed= low tone

Question 16

Excursion

Answer 16

Muscles’ total length between maximally shortened length to maximally stretched length.

Question 17

If max contracted muscle is 3 cm in length, and max stretched state is 9 cm, then excursion is?

Answer 17

6 cm

Question 18

why is excursion important

Answer 18

There is an optimum range in which every muscle contracts most effectively.
This is why there are specific guidelines for MMT.
Without adequate excursion, full joint ROM can not be achieved.

Question 19

Length-Tension Relationship

Answer 19

Multi-joint muscles have length-tension relationship

The inability of a muscle that spans two or more joints to be stretched sufficiently to produce a foil range of motion in all the joints simultaneously

Question 20

Active insufficiency

Answer 20

Active insufficiency: The inability of a muscle to shorten enough to cause full range of motion simultaneously at both joints it passes

Question 21

Passive insufficiency

Answer 21

Passive insufficiency : the inability to further lengthen to provide full range of motion at both joints.

occurs when the muscle cannot be stretched enough to permit full range of motion at both joints at the same time. Examples: - biceps femoris during knee extension and hip flexion

Question 22

Active Insufficiency Examples:

Answer 22

Active Insufficiency Examples:

can’t fully extend hip AND flex knee at same time

Question 23

Passive Insufficiency Examples:

Answer 23

Passive Insufficiency Examples:
make a fist when wrist is fully flexed
full hip flexion and full knee extension

Passive insufficiency of the multijoint muscles of the extensors of the wrist and fingers should limit finger and wrist flexion when they are performed together. Greater range of motion of wrist flexion should be possible with the fingers extended.

Question 24

A muscle that can not be lengthened simultaneously over all the joints it crosses is said to be?

Answer 24

Passively insufficient

Question 25

A muscle that can not contract any further to move both of the joints it crosses is said to be?

Answer 25

Actively insufficient

Question 26

Muscle contraction is strongest when...

Answer 26

Muscle contraction is strongest when it has been stretched first (IMMEDIATELY FIRST) (Kicking a ball = hip extension to flexion)

Question 27

Multi-joint muscles have advantage because...

Answer 27

Multi-joint muscles have advantage in that they contract over one joint while elongating over another (climbing stairs) Flexion of hip (elongates) and knee (shortening), extension of hip (shortening) and knee (elongates)

Question 28

Tenodesis

Answer 28

Extrinsic extensors stretched over radius when wrist is in flexion Extrinsic finger flexors stretched over radius when wrist is in extension

Question 29

Tenodesis functionally important

Answer 29

To people with quadriplegia who have no hand function, but have active wrist extension If your fingers do not work then you can use tenodesis- you can bend your wrist and your fingers will naturally bend NEVER do wrist extension and finger extension at the same time it will fuck up your hands!

Question 30

you have Better contractile ability or better tension when ....

Answer 30

Better contractile ability or better tension when muscle is elongated or stretched before a contraction

Question 31

Length-tension relationship is optimized in

Answer 31

Length-tension relationship is optimized in two-joint or multi-joint muscles i.e. hamstring action in climbing stairs, biceps action in rowing with an oar, intrinsics when typing.

Question 32

Types of muscle contractions

Answer 32

``` Isometric = no joint movement Isotonic = joint movement ```

Question 33

Isotonic | two types

Answer 33

Isotonic = joint movement Concentric = shortening contraction Muscle attachments move closer together Movement occurs against gravity (most cases) Acceleration activity Eccentric = lengthening contraction Muscle attachments move farther away Movement occurs with gravity (most cases) Deceleration activity

Question 34

Agonist

Answer 34

Agonist – Prime Mover, causes motion

Question 35

Antagonist

Answer 35

Antagonist – muscle that performs opposite motion of the agonist

Question 36

Synergist

Answer 36

Synergist – a muscle that works with other muscles to enhance a motion

Question 37

Co-contractor

Answer 37

Co-contractor – when agonist and antagonist contract at the same time

Question 38

Stabilizer

Answer 38

Stabilizer – group of muscles that provide support so that the agonist is more effective (example: the trunk during push-ups)

Question 39

Neutralizer

Answer 39

Neutralizer – prevents unwanted motion | Example: Elbow flexion without supination

Question 40

Open Chain

Answer 40

Open Chain = distal end is free to move in space Ex) holding a bottle of water- distal end can still move/free Ex) walking- open when foot up/ moving, but closed when foot steps nd hits the ground

Question 41

Closed chain

Answer 41

Closed chain = distal chain is fixed Ex) doing push ups- distal end can not move/not free Ex) sitting-standing- legs are closed

Question 42

“length of kinematic chain

Answer 42

“length of kinematic chain” = number of joints involved in completing a particular motion ex-sit- stand = Hip, knee, ankle- 3