Muscle groups and their actions

Question 1

agonist

Answer 1

• prime mover
  -responsible for movement
  -concentric muscle contraction used to identify agonist

Question 2

antagonist

Answer 2

• muscle that has opposite concentric contraction of the agonist
• is eccentric when agonist is concentric

Question 3

synergist

Answer 3

muscle that assists the primary mover to complete an action

Question 4

eccentric

Answer 4

when a muscle lengthens

Question 5

concentric

Answer 5

when a muscle shortens

Question 6

lower extremity: hip flexors

Answer 6

action: hip flexion & trunk flexion
- these 3 muscles make up the iliopsoas
- overtight iliopsoas muscles cause problems often

Question 7

lower extremity: quadriceps

Answer 7

made up of rectus femoris, vastus intermedius, vastus lateralis, & vastus medialis
action: knee extension
- rectus femoris = hip flexion also

Question 8

lower extremity: gluteals

Answer 8

made up of gluteus maximus, gluteus minimus, and gluteus medius
action: hip extension, hip abduction, and hip external rotation
- glute max is biggest muscle
- antagonist = lateral rotators & adductors

Question 9

lower extremity: hamstrings

Answer 9

made up of bicep femoris, semimembranosis, & semitemtendinosis
action: knee flexion & hip extension
- all 2 joint muscles
- most commonly pulled group

Question 10

lower extremity: plantar flexors

Answer 10

made up of gastrocnemius & soleus
action: gastrocnemius - plantar flexion & knee flexion
soleus - plantar flexion

Question 11

upper extremity: deltoid

Answer 11

made up of delt muscle; anterior, posterior, & middle portions
action: anterior - shoulder flexion
middle - shoulder abduction
posterior - shoulder extension

Question 12

upper extremity: biceps brachii

Answer 12

action: shoulder flexion & elbow flexion
- 2 joint muscle
- antagonist = triceps brachii
- makes up 30% of upper arm mass

Question 13

upper extremity: triceps brachii

Answer 13

action: elbow extension & shoulder extension
- 2 joint muscle
- makes up 55% of upper arm mass

Question 14

upper extremity: rotator cuff

Answer 14

action: rotates shoulder
- antagonist = depends, often pec major

Question 15

upper extremity: pectoralis major

Answer 15

action: shoulder horizontal adduction, shoulder adduction, shoulder internal rotation, shoulder flexion

Question 16

trunk: rectus abdominus (abs)

Answer 16

action: trunk flexion
- antagonist = erector spinae
- separated by linea alba

Question 17

trunk: erector spinae

Answer 17

made up of iliocostalis, longissimus, & spinals
action: neck extension, trunk extension, & trunk lateral flexion
- antagonist = rectus abdominus
- stabilizes spine

Question 18

trunk: trapezius

Answer 18

made up of upper, middle, & lower trapezius
action: neck extension, shoulder elevation, & shoulder depression
- antagonist = serratus anterior, pec major

Question 19

trunk: latissimus dorsi (broad back)

Answer 19

action: shoulder extension, shoulder adduction, & shoulder internal rotation
- antagonist = deltoids & trapezius