Shoulder Girdle

Three groups of shoulder muscles

• superficial extrinsic

• deep extrinsic

• intrinsic

Trapezius Upper (descending)

Action: Scapular elevation, upward rotation

Origin: Superior nuchal line

Insertion: Lateral clavicle

Innervation: Spinal accessory nerve CN XI

Trapezius Middle (transverse)

Action: Scapular retraction, upward rotation

Origin: C7-T3 spinous processes

Insertion: Acromion

Innervation: Spinal accessory nerve CN XI

Trapezius Lower (ascending)

Action: Scapular depression, upward rotation

Origin: T4-12 spinous process

Insertion: Spine of scapula

Innervation: Spinal accessory nerve CN XI

Latissimus Dorsi

Action: Shoulder ADDuction, extension, internal rotation

Origin: T7-12 spinous process

Insertion: Bicipital groove of humerus

Innervation: Thoracodorsal nerve (C6-8)

Superficial Extrinsic Muscles

Trapezius - upper, middle, lower

Latissimus dorsi

Deep Extrinsic Muscles

Levator scapulae

Rhomboid minor

Rhomboid major

Levator Scapulae

Action: Scapular elevation, downward rotation

Origin: C1-4 transverse processes

Insertion: Superior angle of scapula

Innervation: Dorsal scapular nerve (C5)

Rhomboid Minor

Action: Scapular retraction, downward rotation

Origin: C7-T1 spinous process

Insertion: Medial border of scapula

Innervation: Dorsal scapular nerve (C5)

Rhomboid Major

Action: Scapular retraction, downward rotation

Origin: T2-5 spinous process

Insertion: Medial border of scapula

Innervation: Dorsal scapular nerve (C5)

Serratus Anterior

Action: Scapular protraction, upward rotation

Origin: Ribs 1-8

Insertion: Medial border and inferior angle of scapula

Innervation: Long thoracic nerve C5-7

Anterior Deltoid

Action: Shoulder flexion, internal rotation

Origin: Lateral clavicle

Insertion: Deltoid tuberosity

Innervation: Axillary nerve C5-C6

Lateral Deltoid

Action: Shoulder ABDuction

Origin: Acromion (scapula)

Insertion: Deltoid tuberosity

Innervation: Axillary nerve (C5-C6)

Posterior Deltoid

Action: Shoulder extension, external rotation

Origin: Spine of scapula

Insertion: Deltoid tuberosity (humerus)

Innervation: Axillary nerve C5-6

Teres Minor

Action: Shoulder external rotation

Origin: Lateral border of scapula

Insertion: Greater tubercle (humerus)

Innervation: Axillary nerve C5-6

Infraspinatus

Action: Shoulder external rotation

Origin: Infraspinatus fossa (scapula)

Insertion: Greater tubercle (humerus)

Innervation: Suprascapular nerve C5-6

Supraspinatus

Action: Shoulder ABDuction

Origin: Supraspinatus fossa (scapula)

Insertion: Greater tubercle (humerus)

Innervation: Suprascapular nerve C5-6

Subscapularis

Action: Shoulder internal rotation

Origin: Subscapular fodder (scapula)

Insertion: Lesser tubercle (humerus)

Innervation: Upper and lower sub scapular nerves C5-6

Teres Major

Action: Shoulder ADDuction, extension, internal rotation

Origin: Inferior angle of scapula

Insertion: Bicipital groove of humerus

Innervation: Lower sub scapular nerve C5-6

Rotator Cuff Muscles

Teres minor

Infraspinatus

Supraspinatus

Subscapularis

Pectoral Muscles

Pectoralis major

Pectoralis minor

Subclavius

Pectoralis Major Clavicular Head

Action: Shoulder ADDuction, flexion, internal rotation

Origin: Medial clavicle

Insertion: Bicipital groove of humerus

Innervation: Lateral posterior nerve C5-7

Pectoralis Major Sternocostal Head

Action: Shoulder ADDuction, flexion, internal rotation

Origin: Sternum, cartilage of true rubs

Insertion: Bicipital groove of humerus

Innervation: Medial pectoral nerve C8-T1

Pectoralis Minor

Action: Scapular protraction, depression

Origin: Ribs 3-5

Insertion: Coracoid process (scapula)

Innervation: Medial pectoral nerve C8-T1

Subclavius

Action: Clavicle: depression Rib 1: elevation

Origin: Rib 1

Insertion: Medial clavicle

Innervation: Subclavian nerve C5-6