Superficial Back Muscles

Question 1

Trapezius:Upper

Answer 1

PA:
med 1/3 superior nuchai line, ext occipital protuberance, lig nuchae SP C7

DA:
post border lat 1/3 clavicle

INN:
Motor: spinal part of the accessory nerve (CN 11) motor innervation
Sensory: Branches from ventral rami (C3,4)

Action:
OC: scapular elevation (upward slide and upward rotation)
CC:
Unilaterally: ipsilateral SB, contralateral rot head and neck.

Question 2

Trapezius: Middle

Answer 2

PA:
SP T1-6 & supraspinous ligs

DA:
med border acromion and sup lip of spine of scapula

INN:
Motor: spinal part of the accessory nerve (CN 11) motor innervation
Sensory: Branches from ventral rami (C3,4)

Action:
OC: scapular retraction (medial slide and ER)

Question 3

Trapezius: Lower

Answer 3

PA:
SP T7-12 & supraspinous ligs

DA:
triangular area med to base of spine of scapula

INN:
Motor: spinal part of the accessory nerve (CN 11) motor innervation
Sensory: Branches from ventral rami (C3,4)

Action:
OC: Scapular upward rotation and downward slide.

Question 4

Latissimus Dorsi

Answer 4

PA:
T7-12 SP, lumbar SP, median sacral crest, supraspinous ligs, and post iliac crest via post layer of thoracolumbar fascia, outer lip of post iliac crest lat to erector spinae, muscular slips to ribs 9-12.

DA:
Floor of bicipital groove

INN:
thoracodorsal nerve : C 6, 7, 8

Actions:
OC: adducts, extends, med rot humerus, assists with scapular depression
C: Trunk elevation

Question 5

Rhomboid Major

Answer 5

PA:
SP T2-5

DA: Med border of scapula b/n root of spine & inferior border

INN:
Dorsal scapular nerve: C4,5

Action:
OC: Scapular retraction (med slide and ER) & downward rot. Assist with upper slide

Question 6

Rhomboid Minor

Answer 6

PA:
SP C7 & T1 & lower log nuchae

DA:
Med border of scapula at level of root of spine

Inn:
Dorsal Scapular Nerve: C4,5

Actions:
OC: Scapular retraction (med slide and ER) & downward rot. Assist with upper slide

Question 7

Levator Scapula

Answer 7

PA:
TP C1-4 & post tubercles of TP C3,4

DA:
Med border scapula b/n sup angle and root of spine

Inn:
Dorsal scapular nerve (C5) & branch of (C3,4) spinal nerves

Action:
OC: upward slide and downward rotation of the scapula.
CC: Ipsilateral SB & rot of neck.