Deck 4: Muscle Activity and Strength

Question 1

A stress-strain curve takes into consideration time as an influencing factor.

Answer 1

False

Question 2

Which of the following is associated with an eccentric contraction?

A) Decreased width of the "A" band
B) The force generated by the muscle is less than the external load.
C) The force generated by the muscle is greater than the external load.
D) Positive work

Answer 2

The force generated by the muscle is less than the external load.

Question 3

With a bi-articular muscle, if neither the proximal or distal end is "fixed" during a contraction of the respective muscle:

A) motion will occur at the proximal joint only
B) motion will occur at the distal joint only
C) motion will occur at both the proximal and distal joints
D) no motion will occur

Answer 3

motion will occur at both the proximal and distal joints

Question 4

Collectively, the endomysium, perimysium, and epimysium form a muscle's ____________ elastic component.

A) series
B) parallel
C) active
D) resisted

Question 5

The cross-sectional area of a muscle is related to the maximal amount of force it is capable of producing.

Question 6

As it relates to connective tissue, all of the following are correct except:

A) Stiffness of a tissue can be defined as the amount of force required to create a change in length or displacement.
B) The initial section of the stress-strain curve is referred to as the "toe region."
C) If a tissue is stretched into the plastic region, upon release of the force which is causing the deformation, the tissue will return to its original resting length.
D) In a resting state, connective tissue has a wavy or crimped appearance.

Question 7

Very rigid structures are more elastic and less viscous.

Question 8

The perpendicular distance from a muscles insertion to the axis of rotation remains constant throughout a joint's range of motion.

Question 9

All of the following statements related to muscle length and tension are true except:

A) The resting length of a muscle is a position of the muscle where there is no tension within the muscle.
B) At a muscle's resting length, a maximal number of actin and myosin cross-bridges are capable of forming.
C) Active tension is responsible for muscle tension during shortening.
D) Passive tension declines as the muscle shortens because there are fewer crossbridges available between actin and myosin fibers.

Question 10

All biological materials can be considered "viscoelastic."

Question 11

Isokinetic devices provide ______________ resistance throughout the range of motion thereby promoting ______________ output of the exercising muscle group.

A) increasing; maximal
B) decreasing; minimal
C) accommodating; maximal
D) accommodating; minimal

Question 12

Which of the following muscles when considered collectively are most representative of those with a high percentage of type IIb fibers?

A) soleus, hamstrings, quadriceps
B) hamstrings, quadriceps, short cervical flexors
C) quadriceps, gastrocnemius, upper extremity flexors
D) gastrocnemius, upper extremity flexors, erector spinae group

Question 13

A shortening contraction of a muscle is synonymous with a(n) _____________ contraction.

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

Question 14

Isokinetic devices operate at a set speed.

Question 15

The _____________ assist the prime movers to produce motion about a joint.

A) agonists
B) synergists
C) antagonists
D) protagonists

Question 16

Given the following arrangement, which muscle orientation would you expect to be able to produce the greatest amount of force? Muscle fibers arranged in ______________ that are architecturally classified as ___________ in shape.

A) series; pennate
B) series; fusiform
C) parallel; pennate
D) parallel; fusiform

Question 17

Creep is best described as the change in length of a tissue in response to a ___________ load over a ____________ period of time.

A) constant; prolonged
B) constant; short
C) variable; prolonged
D) variable; short

Question 18

As it relates to muscle characteristics, the term "stress" is synonymous with "force."

Question 19

From a physiological perspective, this type of muscle contraction is the most efficient (uses the least amount of energy):

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

Question 20

Postural muscles have a high percentage of type IIb muscle fibers.

Question 21

In a rehabilitation setting, enhancing joint stability can be facilitated by performing exercise in a closed kinematic chain.

Question 22

The thicker the size of an axon, the more excitable it is.

Question 23

For maximum tension and hence torque generation across a joint, some muscles are more reliant on muscle length, whereas other muscles are more dependent on the perpendicular distance from the tendon insertion to the axis of rotation.

Question 24

In an open kinematic chain, to optimally function distally, multijoint agonists rely on their antagonists to provide stabilization at proximal joints.

Question 25

A muscle's action and its orientation related to gravity will determine whether a muscle contracts in a concentric or eccentric fashion.

Question 26

For a given force, a greater number of motor units are recruited during an eccentric contraction when compared with a concentric contraction.