Muscle Actions

Question 1

Sternocleidomastoid

Answer 1

Uni - ipsilateral lateral flexion, contralateral rotation

Bi - neck flexion, thoracic cage elevation (inspiration)

Question 2

Scalenes

Answer 2

Anterior - ipsilateral neck flexion, contralateral rotation & bilateral 1st rib elevation, flexion
Middle - ipsilateral neck flexion, contralateral rotation & bilateral 1st rib elevation, flexion
Posterior - ipsilateral neck flexion, contralateral rotation & bilateral 2nd rib elevation**

Question 3

Descending part of trapezius

Answer 3

Uni - ipsilateral flexion of neck

Bi - extension of head/neck

Question 4

Internal intercostals

Answer 4

Depress ribs (forced expiration)

Question 5

External intercostals

Answer 5

Elevate ribs (inspiration)

Question 6

Diaphragm

Answer 6

Separates thoracic & abdominal cavity, primary muscle of respiration

Question 7

External obliques

Answer 7

Uni - contralateral trunk rotation, ipsilateral lateral flexion
Bi - trunk flexion, viscera compression, assist in respiration

Question 8

Transversus abdominus

Answer 8

Compress abdomen, support viscera

Question 9

Rectus abdominus

Answer 9

Trunk flexion, compression of viscera, forced expiration

Question 10

Splenius capitis

Answer 10

Uni - ipsilateral lateral flexion & rotation of head

Bi - extension of head/neck

Question 11

Splenius cervicis

Answer 11

Uni - ipsilateral flexion and rotation of head

Bi - extension of head/neck

Question 12

Erector spinae: iliocostalis

Answer 12

Trunk extension & lateral flexion

Question 13

Erector spinae: longissimus

Answer 13

Trunk extension & lateral flexion (capitis rotates)

Question 14

Erector spinae: spinalis

Answer 14

Trunk extension & lateral flexion

Question 15

Transversospinales: multifidi

Answer 15

Spinal extension & stabilization

Question 16

Transversospinales: semispinales

Answer 16

Thoracis: trunk extension, lateral rotation
Colli: extension, cervical spine rotation
Capitis: extension, rotation of head

Question 17

Transversospinales: rotatores

Answer 17

Trunk extension, rotation & stabilization

Question 18

Pec major

Answer 18

Adduction, internal rotation
Upper: shoulder flexion, horizontal adduction
Lower: shoulder extension

Question 19

Pec minor

Answer 19

Scapular protraction, scapular depression, downward rotation of scapula

Question 20

Subclavius

Answer 20

Stabilizes clavicle

Question 21

Trapezius

Answer 21

Upper: head extension, ipsa lateral flexion of neck, contra lateral rotation, scapular elevation & upward rotation
Middle: scapular adduction & stabilization
Lower: scapular depression & upward rotation

Question 22

Latissimus dorsi

Answer 22

Extension, adduction, internal rotation

Question 23

Levator scapulae

Answer 23

Uni - scapular elevation & downward rotation, ipsilateral neck rotation, lateral neck flexion
Bi - neck extension

Question 24

Rhomboid major

Answer 24

Scapular retraction, downward rotation & elevation

Question 25

Rhomboid minor

Answer 25

Scapular retraction, elevation & downward rotation

Question 26

Deltoid

Answer 26

Anterior: flexion, internal rotation Middle: abduction Posterior: extension, external rotation

Question 27

Supraspinatus

Answer 27

Abduction, stabilization of GH joint

Question 28

Infraspinatus

Answer 28

External rotation, adduction, stabilization of GH joint

Question 29

Teres minor

Answer 29

External rotation, adduction, horizontal abduction, stabilization of GH joint

Question 30

Subscapularis

Answer 30

Internal rotation, stabilization of GH joint

Question 31

Teres major

Answer 31

Adduction, internal rotation, extension

Question 32

Coracobrachialis

Answer 32

Flexion, adduction

Question 33

Biceps brachii

Answer 33

Elbow flexion, supination

Question 34

Brachialis

Answer 34

Elbow flexion

Question 35

Brachioradialis

Answer 35

Elbow flexion

Question 36

Triceps brachii

Answer 36

Elbow extension

Question 37

Anconeus

Answer 37

Elbow extension