Deck 6: The Biomechanics of Human Skeletal Muscle

Question 1

Where is the series elastic component (SEC) of a muscle found?

A) tendons
B) ligaments
C) muscle membrane
D) all of the above

Answer 1

tendons

Question 2

Which of the following is a behavioral property of muscle tissue?

A) ability to develop tension
B) extensibility
C) irritability
D) all of the above

Answer 2

all of the above

Question 3

What type of muscle contraction is employed by the elbow flexors when slowly lowering your backpack to your desk?

A) concentric
B) eccentric
C) isometric
D) isokinetic

Answer 3

eccentric

Question 4

Which of the following most accurately describes a motor unit?

A) a single muscle fiber and a single motor neuron
B) a single motor neuron and all muscle fibers it innervates
C) a single muscle fiber and several motor neurons
D) none of the above

Question 5

Which of the following does not characterize a pennate muscle?

A) relatively strong
B) fibers parallel to long axis of muscle
C) relatively low range of motion
D) all of the above are true

Question 6

Which of the following statements is true?

A) When movement is slow, slow twitch fibers are recruited first.
B) When movement is fast, fast twitch fibers are recruited first.
C) Both A and B are true.
D) None of the above are true.

Question 7

Which of the following types of strength training is particularly associated with subsequent muscular soreness?

A) concentric
B) eccentric
C) isometric
D) all of the above

Question 8

Which of the following statements represents the force-velocity relationship for muscle tissue?

A) contraction is faster when the load is heavier
B) contraction is slower when the load is heavier
C) contraction is slower when the load is lighter
D) the speed of contraction is not affected by the nature of the load

Question 9

A muscle directly involved in causing a segment to move is called what?

A) agonist
B) antagonist
C) neutralizer
D) stabilizer

Question 10

In which of the following activities do the biceps brachii function as antagonists?

A) straightening the elbow during a push-up
B) straightening the elbow during a pull-up
C) curling a barbell from the floor to waist height
D) both A and B

Question 11

Which type of muscle could serve as an antagonist of a flexor?

A) abductor
B) adductor
C) extensor
D) rotator

Question 12

Which of the following time periods is termed electromechanical delay?

A) the time required for conduction of the nerve impulse to the neuromuscular junction
B) the time required for the nerve impulse to cross the neuromuscular junction
C) the time required for the muscle to initiate the development of tension after receipt of the nerve impulse
D) the time required for a muscle to reach peak tension after the development of tension is initiated

Question 13

During the kicking and follow-through phases of a punt, the quads are experiencing what type of contraction?

A) concentric
B) eccentric
C) isometric
D) isokinetic

Question 14

Which of the following is a unique behavioral property of muscle tissue?

A) ability to develop tension
B) extensibility
C) irritability
D) all of the above

Question 15

When flexing the elbow, the biceps brachii, brachioradialis, and brachialis are the three major agonists recruited to perform this movement because all cause flexion at the elbow. However, the biceps also cause supination, an undesired movement. Therefore another muscle acting as a ________, causing ________ must be recruited to prevent the undesired motion.

A) stabilizer, extension
B) neutralizer, extension
C) stabilizer, pronation
D) neutralizer, pronation

Question 16

During the down phase of a knee extension exercise, what role does the hamstring group play?

A) agonist
B) antagonist
C) stabilizer
D) neutralizer

Question 17

A contraction in which there is not a change in length is called what?

A) dynamic
B) isometric
C) concentric
D) isokinetic

Question 18

The elasticity of human skeletal muscle tissue is believed to be due primarily to which of the following?

A) the parallel elastic component
B) the series elastic component
C) the continuous elastic component
D) the active elastic component

Question 19

Which of the following types of muscle tension is commonly used as a braking mechanism to slow limb movement?

A) eccentric
B) isotonic
C) concentric
D) isometric

Question 20

Which of the following statements is/are true?

A) Pennate muscles are capable of producing more tension per unit of cross-sectional area than parallel muscles.
B) Parallel muscles are capable of producing more range of motion than pennate muscles.
C) Both A and B are true.
D) Neither A nor B is true.

Question 21

Which of the following is a potential disadvantage of multijoint muscles?

A) active insufficiency
B) passive insufficiency
C) both A and B
D) none of the above

Question 22

Which behavioral property of muscle tissue is defined as "the ability to respond to a stimulus"?

A) elasticity
B) irritability
C) extensibility
D) contractility

Question 23

The force-velocity relationship implies which of the following?

A) It is impossible to move a heavy resistance at a fast speed.
B) It is impossible to move a light load at a slow speed.
C) both A and B
D) none of the above

Question 24

Which of the following is/are characteristic of fast-twitch oxidative glycolytic fibers?

A) Contraction speed is intermediate (faster than type I but slower than type IIB).
B) Fatigue rate is intermediate (faster than type I but slower than type IIB).
C) both A and B
D) none of the above

Question 25

In human skeletal muscle, force generation capability is highest in which of the following conditions?

A) muscle is at resting length
B) muscle is slightly shortened
C) muscle is slightly lengthened
D) muscle length is irrelevant to force production

Question 26

The torque of a muscle (rotary component) is greatest in what position?

A) when the moment arm is longest
B) when the muscle insertion is 90° to the bone
C) both A and B
D) position does not affect torque

Question 27

Which of the following is/are characteristic(s) of muscle fatigue?

A) reduction in muscle force
B) reduction in shortening velocity
C) prolonged relaxation of motor units between recruitment
D) both A and B
E) all of the above

Question 28

During the first 12 weeks of resistance training, strength gains are due primarily to what?

A) improved innervation of the muscle
B) increase in cross-sectional area
C) both A and B
D) none of the above

Question 29

Which of the following likely contributes to the stretch-shortening cycle?

A) the series elastic component
B) muscle spindle activity
C) both A and B
D) none of the above

Question 30

The opposite of muscular endurance is what?

A) muscular strength
B) muscular fatiguability
C) muscular power
D) muscular flexibility

Question 31

Muscle hypertrophy in humans is primarily due to what?

A) increase in number of muscle fibers
B) increase in size of muscle fibers
C) both A and B
D) none of the above

Question 32

When the wrist is flexed, the finger flexors cannot produce as tight a fist as when the wrist is in a neutral position. This is an example of what?

A) active insufficiency
B) passive insufficiency
C) both A and B
D) none of the above

Question 33

During the execution of a pull-up when the chin is over the bar, which force exerted by the biceps brachii is greatest at the elbow?

A) the rotary force
B) the stabilizing force
C) the dislocating force
D) the "pinching" force

Question 34

The component force which is parallel to the moving bone and acts to pull the bones together at the joint is called what?

A) curvilinear force
B) stabilizing force
C) rotary force
D) dislocating force

Question 35

A single muscle cell is called what?

A) fiber
B) neuron
C) unit
D) none of the above

Question 36

When an opposing torque at a joint is greater than the torque created by a muscle, what type of contraction occurs in that muscle?

A) isometric
B) isotonic
C) concentric
D) eccentric

Question 37

Which of the following terms best describes the rate of torque production at a joint?

A) mechanical work
B) muscular power
C) muscular energy output
D) muscular strength

Question 38

Which of the following is true regarding the parallel elastic component (PEC) of muscular elasticity?

A) This component is provided by the muscle membranes.
B) This component provides resistance when a muscle is passively stretched.
C) This is the component primarily responsible for the elasticity of muscle.
D) both A and B
E) all of the above

Question 39

The amount of torque a muscle group can generate at a joint is used to measure what?

A) muscular power
B) muscular endurance
C) muscular strength
D) muscular flexibility

Question 40

Which of the following is true regarding the stretch-shortening cycle?

A) When a muscle is stretched just prior to contraction, the resulting contraction is more forceful.
B) An eccentric contraction is followed by a concentric contraction.
C) The SSC promotes storage of elastic energy.
D) both A and B
E) all of the above

Question 41

The _________________ fiber arrangement is a pattern of fibers within a muscle with short fibers attaching to one or more tendons.

Question 42

Explain the four roles assumed by muscles.

Question 43

A pattern of eccentric contraction followed immediately by concentric contraction is called ____________________ cycle.

Question 44

List and describe four common muscle injuries.

Question 45

List and explain the behavioral characteristics of the musculotendinous unit, including similarities and differences to other tissue.

Question 46

A __________________ muscle fiber reaches peak tension relatively slowly.

Question 47

Delayed onset muscle soreness is associated more with isometric training than with concentric or eccentric training.

Question 48

___________________ is a role played by a muscle to stabilize a body part against some other force.

Question 49

A muscle contraction which does not result in a change in length is called ___________________.

Question 50

Electrochemical delay in children is longer than in adults.

Question 51

Explain muscular strength. How is it measured? How does it change at different points during range of motion?

Question 52

Hamstring strains are slow to heal and have a high incidence of reoccurrence.

Question 53

Graphically display the force-velocity relationship including explanation.

Question 54

Although muscle fibers are typically categorized by three types, there is actually a continuum of fiber characteristics.

Question 55

There is good evidence that regular, lifelong, high-intensity exercise can reduce the loss of motor units typically associated with aging.