Innervation, Arterial Supply, and Actions of the back and shoulder muscles

Neck arterial blood supply

Vertebral and cervical arteries

Thoracic arterial blood supply

Posterior intercostal arteries

Abdominal arterial blood supply

Subcostal and lumbar arteries

Pelvis arterial blood supply

Iliolumbar and sacral arteries

General innervation of extrinsic back muscles

Innervated by the anterior rami (except Trapezius)

General innervation of intrinsic back muscles

Innervated by the posterior rami

Innervation of the Trapezius

Cranial nerve 11 (spinal accessory nerve) and anterior rami

Arterial supply of the Trapezius

Transverse cervical artery

Actions of the Trapezius

Scapula elevation, depression, retraction, and upward rotation

Innervation of the Latissimus dorsi

Thoracodorsal nerve

Arterial supply of the Latissimus dorsi

Thoracodorsal artery

Actions of the Latissimus dorsi

Adduct, extend, and medially rotate the arm

Innervation of the Levator scapulae

Dorsal scapular nerve and anterior rami

Action of the Levator scapulae

Elevates scapula

Arterial supply of the Levator scapulae

Dorsal scapular artery

Innervation of the Rhomboid major and minor

Dorsal scapular nerve

Arterial supply of the Rhomboid major and minor

Dorsal scapular artery

Actions of the Rhomboids

Retract, elevate, and inferiorly rotate the scapula

List of extrinsic back muscles

Trapezius, latissimus dorsi, rhomboid major/minor, and levator scapulae

Action of the Serratus posterior superior

Elevates the ribs during respiration

Action of the Serratus posterior inferior

Depresses ribs during respiration

Intermediate muscles of the back

Serratus posterior superior and inferior

Three muscles of the Erector spinae group

Iliocostalis, longissimus, and spinalis

Innervation of the Erector spinae

Posterior rami

Bilateral action of the Erector spinae

Extension of vertebral column and head

Unilateral action of the Erector spinae

Lateral bending

Innervation of the Splenius

Posterior rami

Bilateral action of the Splenius

Extend the head

Unilateral action of the Splenius

Rotate the head and lateral bend the head

Three muscles of the Transversospinalis group

Semispinalis, multifidus, and rotatores

Innervation of the Transversospinalis

Posterior rami

Action of the Semispinalis

Extend and rotate the head and neck

Action of the Multifidus

Stabilize the vertebral column

Action of the Rotatores

Stabilize the vertebral column

Innervation of the Supraspinatus

Suprascapular nerve

Actions of the Supraspinatus

Humeral stabilization and initiation/assistance in humeral abduction

Innervation of the Infraspinatus

Suprascapular nerve

Actions of the Infraspinatus

Humeral stabilization and external rotation

Innervation of the Teres minor

Axillary nerve

Actions of the Teres minor

Humeral stabilization and external rotation

Innervation of the Teres major

Lower subscapular nerve

Actions of the Teres major

Humeral internal rotation and adduction

Innervation of the Subscapularis

Upper and lower subscapular nerves

Actions of the Subscapularis

Humeral stabilization, adduction, and internal rotation

Innervation of the Deltoid

Axillary nerve

Primary action of the Deltoid

Humeral abduction

Secondary actions of the Deltoid

Humeral flexion, internal and external rotation, and extension

The two heads of the Pectoralis major

Clavicular head and sternocostal head

General innervation of the Pectoralis major

Lateral and medial pectoral nerves

General actions of the Pectoralis major

Humeral adduction and medial rotation (both heads)

Innervation of the Pectoralis major clavicular head

Lateral pectoral nerve

Action of the Pectoralis major clavicular head

Flexion of the arm

Innervation of the Pectoralis major sternocostal head

Medial pectoral nerve

Action of the Pectoralis major sternocostal head

Extension of the flexed arm

Innervation of the Pectoralis minor

Lateral and medial pectoral nerves

Actions of the Pectoralis minor

Scapular stabilization; pulls the scapula anteriorly and inferiorly

Innervation of the Subclavius

Nerve to subclavius

Action of the Subclavius

Draws the clavicle medially

Innervation of the Serratus anterior

Long thoracic nerve

Actions of the Serratus anterior

Scapular stabilization, protraction, and upward rotation

Artery located in the Triangular Space

Circumflex scapular artery

Artery located in the Quadrangular Space

Posterior circumflex humeral artery

Nerve located in the Quadrangular Space

Axillary nerve

Artery located in the Triangular Interval

Profunda brachii artery (deep artery of the arm)

Nerve located in the Triangular Interval

Radial nerve

Most lateral Erector spinae muscle

Iliocostalis

Intermediate Erector spinae muscle

Longissimus

Most medial Erector spinae muscle

Spinalis

Functional role of the rotator cuff group

Humeral stabilization at the glenohumeral joint