Muscle Mechanics

Question 1

Adverse effects of stretching only occur when the stretch is held for longer than

Answer 1

45 sec

Question 2

What are the acute effects of stretching?

Answer 2

decreased strength, power, speed and movement performance=bad

Question 3

pre-exercise stretching is OK is it lasts less than

Answer 3

30 sec

Question 4

What is the stretch reflex (muscle spindle)

Answer 4

contraction in response to quick stretch

Question 5

What is autogenic inhibition (golgi tendon organ)

Answer 5

immediate inhibition of muscle following contraction

Question 6

What is reciprocal inhibition (muscle spindle)

Answer 6

inhibition of antagonist muscle during agonist contraction

Question 7

Both Length tension and Force velocity assume a single muscle fiber maximally stimulated. what is the difference regarding assumptions

Answer 7

LT - held at a constant length (isometric)

FV - Load is held constant (isotonic) while allowed to shorten or forcibly lengthened

Question 8

What are the effects of aging on skeletal tissue

Answer 8

increased intermuscular adipose tissue
lower neuromuscular activation
properties of single fibers preserved despite reductions in whole muscle CSA
selective atrophy of TYPE II fibers

Question 9

You lose 1% of muscle mass per year after age

Answer 9

40

Question 10

after the age of 40 muscle strength decreases___ as fast

Answer 10

3X

Question 11

T or F Exercise can reverse the effects of aging on skeletal muscle

Answer 11

F. it can slow but not reverse

Question 12

Regarding propulsive energy, which generates more, mono or bi-articulate muscles?

Answer 12

Mono

Question 13

What do bi-articulate muscles allow for?

Answer 13

1- power transfer between joints (net transfer from proximal to distal)
2-efficient conversion of energy into desired movements

Question 14

Multi-joint muscle is unable to contract forcefully in a _____ position

Answer 14

shortened. think forceful fist in wrist flexion

Question 15

what is active insufficiency

Answer 15

decreased tension as length is insufficient (resting length)

Question 16

when a multi-joint muscle is unable to be stretched sufficiently to produce a full range of motion in all the joints simultaneously

Answer 16

passive insufficiency

Question 17

example of passive insufficiency

Answer 17

finger flexion while in wrist flexion

Question 18

What is the role of bi-articular muscles for a uni-articular motion?

Answer 18

role shifts to coordination of movement

Question 19

What is good about stretching?

Answer 19

Increases range of motion

decreases musculotendinous stiffness

Question 20

A tendon is considered to be a _____ component in the biomechanical muscle model

Answer 20

series elastic

Question 21

According to the Lieber article, the eccentric slide of the force-velocity curve tells us muscles are resistant to lengthening. The functional reason for this is

Answer 21

it allows muscles to serve as brakes and to absorb momentum which allows for controlled movement

Question 22

The Henneman size principle states that

Answer 22

small motor neurons are recruited before large neurons to allow smooth and controlled force development

Question 23

According to the concentric slide of the force velocity curve, as contraction velocity increases,

Answer 23

tension development decreases