Chp 10-Types of Muscle Contractions

Question 1

Types of Muscle Contractions

Answer 1

1. Agonist
2. Antagonist
3. Synergists
4. Fixators

Question 2

Agonist

Answer 2

the prime mover; the muscle which performs the movement in question
- e.g., biceps brachii is agonist of elbow flexion.

Question 3

What type of move does Agonist muscles do?

Answer 3

Concentric (on-center) movement

Question 4

Antagonist

Answer 4

the muscle that performs the opposing movement to that of the agonist
- e.g., triceps brachii is antagonist of elbow flexion (or agonist of elbow extension).

Question 5

What type of movement does Antagonist do?

Answer 5

Off-center (eccentric) movement – the eccentric muscle may be “contracting” to exert tension so agonist doesn’t overshoot or to slow/stop the agonist movement.

Question 6

What does both agonist and antagonist muscles do?

Answer 6

Both muscles contract (exert tension) regardless of which is the agonist or antagonist.

Question 7

Synergists

Answer 7

either aids agonist w/ a little more force or reduces unwanted movement elsewhere (a fixator).
e.g., plantaris m in popliteal fossa aids knee flexion

Question 8

Fixators

Answer 8

when synergist immobilizes or stabilizers movements – ie., prevents movement
e.g., rhomboids mm. help stabilize scapula

Question 9

Agonist muscle(s) example?

Answer 9

• e.g., biceps brachii is agonist of elbow flexion.

Question 10

Antagonist muscle(s) example?

Answer 10

e.g., triceps brachii is antagonist of elbow flexion (or agonist of elbow extension).

Question 11

Synergists muscle(s) example?

Answer 11

e.g., plantaris m in popliteal fossa aids knee flexion

Question 12

Fixators muscle(s) example?

Answer 12

e.g., rhomboids mm. help stabilize scapula