W-1 Extrinsic Back

Trapezius

Upper fibers:

• Extend head and neck (bilaterally)

• Lateral flexion to same side

• Rotation to opposite side

• Elevation and upward rotation of scapula

Trapezius

Middle fibers:

• Adduct and stabilize scapula

Trapezius

Lower fibers:

• Depress and upward rotation of scapula

Trapezius

Origin • External occipital protuberance, ligamentum

nuchae, C1-C7 spinous processes

• Spinous processes of T1-T4

• Spinous processes of T5-T12

Trapezius

Insertion • Lateral 1/3 of clavicle

• Medial aspect of acromion

• Upper crest and tubercle of scapular spine

Trapezius

Innervation Accessory nerve (CN XI); ventral rami C2-C4

Trapezius

Blood Supply Transverse cervical artery

Trapezius

Purposeful Activity: Reaching for an object overhead, rowing a canoe

Latissimus Dorsi

Purposeful

Activity: Wheelchair mobility; sit to stand with UEs

Latissimus Dorsi

Action: Shoulder Extension, adduction, IR Aids in respiration

Latissimus Dorsi

Origin: Inferior angle of the scapula; 9-12 ribs; Spinous processes of T7-T12; thoracolumbar fascia; posterior 1/3 of iliac crest

Latissimus Dorsi

Insertion: Crest of the lesser tuberosity of humerus and intertubercular groove

Latissimus Dorsi

Innervation: Thoracodorsal nerve (C6-C8)

Latissimus Dorsi

Blood Supply Thoracodorsal artery

Levator Scapulae

Purposeful

Activity: Shrugging shoulders; carrying a briefcase

Levator Scapulae

Action: Scapular elevation, downward rotation Head/neck lateral flexion Head/neck rotation to the same side

Levator Scapulae

Origin: C1-C4 transverse processes

Levator Scapulae

Insertion: Medial border of scapula between superior angle and superior portion of scapular spine

Levator Scapulae

Innervation: Dorsal scapular nerve (C4-C5) , C3 and C4 nerves

Levator Scapulae

Blood Supply: Transverse cervical artery, ascending cervical artery

Rhomboid Major

Purposeful Activity: Reaching into back pocket

Rhomboid Major

Action: Scapular retraction, downward rotation, and elevation

Rhomboid Major

Origin: Spinous processes of T2-T5

Rhomboid Major

Insertion: Medial border of scapula inferior to spine

Rhomboid Major

Innervation: Dorsal scapular nerve (C4-C5)

Rhomboid Major

Blood Supply: Dorsal scapular artery

Rhomboid Minor

Purposeful Activity: Reaching into back pocket

Rhomboid Minor

Action: Scapular retraction, elevation, and downward rotation

Rhomboid Minor

Origin: Spinous processes C7-T1 and inferior nuchal ligament

Rhomboid Minor

Insertion: Medial border of scapula across from scapular spine

Rhomboid Minor

Innervation: Dorsal scapular nerve (C4-C5)

Rhomboid Minor

Blood Supply Dorsal scapular artery

Serratus Posterior Superior

Purposeful Activity: Breathing

Serratus Posterior Superior

Action: Rib elevation

Serratus Posterior Superior

Origin: C7-T3 spinous processes; nuchal ligament

Serratus Posterior Superior

Insertion: Superior margin of ribs 2-5

Serratus Posterior Superior

Innervation: Branches of dorsal primary rami T1-T4

Serratus Posterior Superior

Blood Supply: Posterior intercostal arteries

Serratus Posterior Inferior

Purposeful Activity: Breathing

Serratus Posterior Inferior

Action: Rib depression

Serratus Posterior Inferior

Origin: T12-L3 spinous processes and thoracolumbar fascia

Serratus Posterior Inferior

Insertion: Lateral inferior margins of ribs 9-12

Serratus Posterior Inferior

Innervation: Branches of dorsal primary rami T9-T12 spinal nerves

Serratus Posterior Inferior

Blood Supply Posterior intercostal arteries; lumbar arteries