HK 3501 MUSCLES

thoroappendicular - extrinsic muscles of the back -5 muscles

extrinisc superficial:

extrinsic deep:

extrinisc superficial: latissimus dorsi, trapezius

extrinsic deep: levator scapulae, rhomboid minor, rhomboid major

trapezius

O:

I:

A:

N:

O: base of skull, supraspinous& nuchal ligament, SP C7-T12

I: lateral 1/3 clavicle, acromion, spine of scapula (the more medial border horseshoe)

A:

upper trap- elevate scapula

mid trap- retract scapula

lower trap- depress scapula, upward/lateral rotation of scapula (glenoid up)

N: spinal accessory nerve

latissimus dorsi

O:

I:

A:

N:

O: SP of C7-L5, iliac crest, thoracolumbar fascia

I: floor of the lesser tubercle of humerus

A: elevate thoratic region in climbing, adduct humerus, medial rotation of humerus, extend humerus

N: anterior rami (thoracodorsal nerve)

levator scapulae

O:

I:

A:

N:

O: TP of C1-C4

I: medial border above spine scapula

A: elevate scapula, rotate scapula medial/down (glenoid down)

N: dorsal scapular nerve

rhomboid minor

O:

I:

A:

N:

O: SP C7-T1

I: medial border of scapula at level of spine of scapula

A: retract scapula, rotate scapula down/medial (glenoid down)

N: dorsal scapular nerve

rhomboid major

O:

I:

A:

N:

O: SP T2-T5

I: medial border of scapula below spine of scapula

A: retract scapula, rotate scapula down/medial (glenoid down)

N: dorsal scapular nerve

common features of all extrinisc deep throaticoappendicular muscles?

all innervated by the dorsal scapular nerve

all have rotate scapula down/medial (glenoid down) as an action

Scapulohumoral muscles- intrinsic shoulder muscles(originate on scapula, insert on humerus)- 6 muscles

4 muscles of rotator cuff:

other 2:

4 muscles of rotator cuff: supraspinatus, infraspinatus, teres minor, subscapularis

other 2: teres major, deltoid

supraspinatus

O:

I:

A:
N:

O: supraspinous fossa of scapula

I: superior facet of the greater tubercle of the humerus

A: abduct humerus, stabilize shoulder joint
N: suprascapular nerve

infraspinatus

O:

I:

A:
N:

O: infraspinous fossa of the scapula

I: middle facet of the greater tubercle of humerus

A: lateral rotation of humerus, stabilize shoulder joint
N: suprascapular nerve

teres minor

O:

I:

A:
N:

O: upper 2/3 of the posterior lateral border of the scapula

I: inferior facet of the greater tubercle of humerus

A: lateral rotation of humerus, stabilize shoulder joint
N: auxillary nerve

subscapularis

O:

I:

A:
N:

O: subscapular fossa (anterior)

I: lesser tubercle of humerus

A: medial rotation of humerus, stabilize shoulder joint
N: upper and lower subscapular nerves

deltoid

O:

I:

A:
N:

O: “lateral bony horseshoe” lateral 1/3 of clavicle, acromion, spine of scapula

I: deltoid tuberosity on lateral humerus

A:

anterior delt- flex humerus, medial rotation

mid delt- abduct humerus

posterior delt: extend humerus, lateral rotation
N: auxillary nerve

teres major

O:

I:

A:
N:

O: inferior angle of the lateral border of scapula

I: medial lip of the intertubercular groove of humerus

A: adduct humerus, extend humerus, medial rotation
N: lower subscapular nerve

what muscles are the divisor between anterior rami innervation and posterior rami innervation of the back muscles? (with exception of intertransverserii which has both)

serratus posterior superior and serratus posterior inferior

serratus posterior superior

O:

I:

A:
N:

O: SP C7-T2

I: ribs

A: elevate ribs, proprioception
N: anterior rami (intercostal)

serratus posterior inferior

O:

I:

A:
N:

O: SP T11-L2

I: ribs

A: depress ribs
N: anterior rami (intercostal)

what is the most superficial intrinsic back muscle

splenius

splenius capitus

O:

I:

A:
N:

O: SP C7-T3

I: mastoid process

A: lateral flexion of neck or extension of neck, rotation of neck
N:posterior rami

splenius cervis

O:

I:

A:
N:

O: SP C3-T6

I: TP C1-C3

A: lateral flexion of neck or extension of neck, rotation of neck
N: posterior rami

immidiate intrinsic basck muscles include:

erector spinae - ILS muscles

deep intrinsic back muscles include:

transversospinales- SMR muscles

deeper (minor) intrinsic back muscles include:

segmental- IIL muscles

iliocostalis

O:

I:

A:
N:

O: lumbar SP, sacrum, iliac crest

I: angles of the lower ribs

A: both sides: extends vertebral column, one side: lateral flexion
N: posterior rami

longissimus

O:

I:

A:
N:

O: lumbar SP, sacrum, iliac crest

I: TP, mastoid process

A: both sides: extends vertebral column, one side: lateral flexion
N: posterior rami

spinales

O:

I:

A:
N:

O: lumbar SP, sacrum, iliac crest

I: SP

A: both sides: extends vertebral column, one side: lateral flexion
N: posterior rami

semispinales (4-6) ONLY CERVICAL AND THORACIC REGION

O:

I:

A:
N:

O: TP

I: SP

A: extend, rotate, stabilize vertebral column
N: posterior rami

multifidus (2-4)

O:

A:
I:

N:

O: sacrum and TP

I: SP

A: extend, rotate, stabilize vertebral column
N: posterior rami

rotatores (1-2)

O:TP

I: spinous processes

A: extend, rotate, stabilize vertebral column
N: posterior rami

interspinales

O:

I:

A:
N:

O: SP

I: SP

A: extend vert column, stabalize vert column
N: posterior rami

intertransversarii

O:

I:

A:
N:

O: TP

I: TP

A: lateral flexion of vert column, stabilize vert column
N: posterior AND anterior rami

levator costarum

O:

I:

A:
N:

O: cervical and thoracic TP

I: ribs

A: elevate ribs
N: posterior rami

Pectoralis major

O:

I:

A:

N:

O: medial ½ clavicle, manubrium, sternum

I: lateral lip of the intertubercular groove of humerus

A: adduction of humerus, medial rotation of humerus

clavicular head- flexion of humerus

sternocostal head- extension of humerus

N: median and lateral pectoral nerves

Pectoralis minor

O:

I:

A:

N:

O: ribs 3-5

I: coracoid process of the scapula

A: stablaize scapula, forward stretch of arm, hold scapula inferiorly and anteriorly against thorax

N: median and lateral pectoral nerves

serratus anterior

O:

I:

A:

N:

O: lateral ribs 1-8

I: anterior medial border of scapula

A: protract scapula, hold scapula to thorax, rotate scapula (glenoid up)

N: long thoracic nerve

subclavis

O:

I:

A:

N:

O: rib 1

I: middle 1/3 of the inferior scapula

A: anchor clavicle, depress clavicle, prevent clavicle dislocation at strenoclavicular joint (ex tugging rope)

N: nerve to subclavis (small)

muscles of posterior axilla

subscapularis, latissimus dorsi, teres major

muscle of the medial wall of axilla

serratus anterior

muscles of anterior axilla

pectoralis major, pectoralis minor, subclavis