2Nd Order - All

Front 1

Trapezius
A (4)
N (2)
I (2)
O (4)

Back 1

A:
- extends & lat. flexes neck;
- stabilizes scapula & shoulder during arm movements;
- elevates apex of shoulder;
- acts w/ other MM to rotate & retract scapula
N:
- Accessory N
- ant. rami of C3-C4
I:
- acromion & spine of scapula
- lat. 1/3 of clavicle
O:
- ext. occipital protuberance
- medial 1/3 of superior nuchal line
- nuchal ligament
- spinous processes of C7-T3

Front 2

Latissimus dorsi
A (4)
N
I
O (4)

Back 2

A:
- add. & med. rotates humerus
- extends shoulder joint
- backward swing of arm
- aids in deep inspiration, sudden expiration, & prolonged forceful expiration
N: Thoracodorsal N
I: floor of intertubercular sulcus of humerus
O:
- T7-L5
- lower 3-4 ribs
- iliac crest
- thoracolumbar fascia

Front 3

Rhomboid major
A (2)
N
I
O

Back 3

A:
- retract scapula & brace shoulder
- fix scapula during arm movements
N: Dorsal scapular N
I: medial border of scapula
O: SP of T2-T5

Front 4

Teres minor
A (2)
N
I (2)
O

Back 4

A:
- modulates axn of deltoid; prevent humeral head from sliding upward as arm is abd.
- lat. rotates humerus
N: Axillary N
I:
- greater tubercle of humerus
- post. surface of joint capsule
O: lat. border & adjacent post. surface of scapula

Front 5

Supraspinatus
A (2)
N
I
O

Back 5

A:
- aids deltoid in abd. of humerus
- resists downward slippage of humeral head
N: Suprascapular N
I: greater tubercle of humerus
O: supraspinous fossa of scapula

Front 6

Subscapularis
A (2)
N
I (2)
O

Back 6

A:
- modulates axn of deltoid; prevents humeral head from sliding upward as arm is abd.
- med. rotates humerus
N: Upper & Lower Subscapular NN
I:
- lesser tubercle of humerus
- ant. surface of joint capsule
O: subscapular fossa of scapula

Front 7

Serratus anterior
A (5)
N
I
O

Back 7

A:
- (w/ pec. minor) draws scapula laterally & forward around chest wall
- protracts scapula
- prime mover in all forward-reaching & pushing axns
- aids in rotationg scapula to elevate apex of shoulder
- fixes scapula during abd.of arm
N: Long thoracic N
I: medial border of scapula
O: all or nearly all ribs

Front 8

Serratus posterior inferior
A
N
I
O

Back 8

A: depresses ribs
N: ant. rami T9-T12
I: ribs 8-12
O: SP of T11-L2

Front 9

Splenius capitis
A (2)
N
I
O (2)

Back 9

A:
- (unilat.) ipsilat. flexion & slight rotation of head
- (bilat.) extend head
N: post. rami of middle C spinal NN
I: mastoid process & occipital bone just inf. to superior nuchal line
O:
- nuchal ligament
- SP of C7-T6

Front 10

Erector spinae group (iliocostalis, longissimus, spinalis)
A (2)
N
I (3)
O (4)

Back 10

A:
- extension & lat. flexion of vert. column
- longissimus capitis also ipsilat. rotates the head
N: post. rami of C - L spinal NN
I:
- mastoid process
- C & T vert.
- all ribs
O:
- nuchal lig.
- ribs 3-12
- T & L vert.
- median & lat. sacral crests

Front 11

Semispinalis capitis & cervicis
A
N
I (2)
O (2)

Back 11

A: extend & contralat. rotate head
N: post. rami of C & T spinal NN
I:
- occipital bone between nuchal lines
- SP's of C2-C5
O:
- AP's of C4-C7
- TP's of T1-T6

Front 12

Semispinalis thoracis
A
N
I
O

Back 12

A: extension & contralat. rotation of vert. column
N: post. rami of C & T spinal NN
I: vert. C6-T4
O: vert. T6-T10

Front 13

Multifidus
A (3)
N
I
O (4)

Back 13

A:
- stabilize adjacent vert.
- maintain posture
- control vert. movement when erector spin. act
N: post. rami of C-L spinal NN
I: laminae & SP's of vert. superior to origins
O:
- vert. C4-L5
- post. sup. iliac spine
- sacrum
- apon. of erector spinae

Front 14

Rotatores

Back 14

A:
- (unilat.)
- (bilat.)
N:
I:
O: