Mechanical Principles Muscle Actions- Final

Question 1

sternocleidomastoid

Answer 1

Both Sides: flexion of neck
Right side: rotation to left and lateral flexion to right
Left side: rotation to right and later flexion to left

Question 2

Rectus abdominis

Answer 2

Both sides: lumbar flexion
posterior pelvic rotation
right side: weak lateral flexion to the right
Left side: wak lateral flexion to the left

Question 3

External oblique abdominal

Answer 3

both sides: lumbar flexion
posterior pelvic rotation
Right: lumbar lateral flexion to the right, rotation to the left and lateral pelvic rotation to the left
Left:lumbar lateral flexion to left, rotation to right, lateral pelvic rotation to right

Question 4

internal oblique abdominal

Answer 4

both sides: lumbar flexion
posterior pelvic rotation
right: lumbar lateral flexion to right, rotation to right, lateral pelvic rotation to left
Left: lumbar lateral flexion to left, rotation to left, and lateral pelvic rotation to right

Question 5

Transversus abdominis

Answer 5

compression of abdominal cavity, forced expiration by pulling the abdominal wall inward

Question 6

Trapezius

Answer 6

upper fibers: elevation of scapula, extension and rotation of cranium and neck
middle fibers: scapular elevation, upward rotation, adduction
Lower fibers: depression, adduction and upward rotation

Question 7

Deltoid

Answer 7

anterior fibers: abduction, flexion, horizontal adduction, and internal rotation
middle fibers: abduction
posterior fibers abduction, extension, horizontal abduction, and external rotation

Question 8

pectoralis major

Answer 8

upper fibers: internal rotation, horizontal adduction, flexion
Lower fibers: internal rotation, horizontal adduction, extension, and adduction

Question 9

Latissimus dorsi

Answer 9

adduction
extension
internal rotation
horizontal abduction

Question 10

biceps brachii

Answer 10

flexion of elbow, supination of forearm, weak flexion of shoulder joint, weak abduction of shoulder joint when externally rotated

Question 11

triceps brachii

Answer 11

all heads: extension of elbow

Long head: extension of shoulder joint, adduction of shoulder joint, horizontal abduction

Question 12

tensor fasciae latae

Answer 12

abduction of hip
flexion of hip
anterior pelvic rotation

Question 13

gluteus maximus

Answer 13

extension of hip
external rotation of hip
upper fibers assist in abd.
lower fibers assist in add.
posterior pelvic rotation

Question 14

semitendinosus

Answer 14

flexion of knee
extension of hip
internal rotation of hip
IR of flexe knee
Posterior pelvic rotation

Question 15

semimembranosus

Answer 15

flexion of knee
ext. of hip
IR of hip
IR of flexed knee
Post. pelvic rotation

Question 16

biceps femoris

Answer 16

flexion of knee
extension of hip
ER of hip
ER of flexed knee 
Posterior pelvic rotation

Question 17

adductor magnus

Answer 17

add of hip
ER as hip adducts
ext. of hip

Question 18

agonist muscles of hip flexion

Answer 18

psoas
iliacus (iliopsoas)
rectus femoris
pectineus
sartorius
tensor fasciae latae

Question 19

agonist muscles of hip extension

Answer 19

gluteus maximus
biceps femoris (long head)
semitendinosus
semimembranosus

Question 20

rectus femoris

Answer 20

flexion of hip
ext. of knee
anterior pelvic rotation

Question 21

vastus lateralis, medialis and intermedius

Answer 21

ext. of knee

Question 22

gastrocnemius

Answer 22

plantar flexion of ankle

flexion of knee

Question 23

soleus

Answer 23

plantar flexion of ankle