Muscles Crossing the Shoulder Joint - Produce movements of Arm (Humerus) at Shoulder Joint

Latissimus Dorsi

A: Extends, adducts, and medially rotates arm

Latissimus Dorsi

O: Thoracolumbar Fascia, Iliac Crest, Lower 3 Ribs

Latissimus Dorsi

I: Humerus (Intertubercular Groove/Sulcus)

Pectoralis Major

A: Extends, adducts, and medially rotates arm

Pectoralis Major

O: Sternum, Clavicle, Cartilage of ribs 1-7, Abdominal Aponeuroses

Pectoralis Major

I: Humerus (Greater Tubercle)

Deltoid

A:

As a unit: Abduction of arm (different fiber groups responsible for flexion, extension, medial and lateral rotation of arm)

Deltoid

O: Clavicle, Scapula

Deltoid

I: Humerus (Deltoid Tuberosity)

Subscapularis of Rotator Cuff

A: Medial rotation of Arm, fused to underlying capsule of the shoulder joint and strengthens it

Subscapularis of Rotator Cuff

O: Scapula (subscapular fossa)

Subscapularis of Rotator Cuff

I: Humerus (lesser tubercle)

Supraspinatus of Rotator Cuff

A: Abduction of arm, fused to underlying capsule of the shoulder joint and strengthens it

Supraspinatus of Rotator Cuff

O: Scapula (subscapular fossa)

Supraspinatus of Rotator Cuff

I: Humerus (greater tubercle)

Infraspinatus of Rotator Cuff

A: Lateral rotation of arm, fused to underlying capsule of the shoulder joint and strengthens it

Infraspinatus of Rotator Cuff

O: Scapula (infraspinous fossa)

Infraspinatus of Rotator Cuff

I: Humerus (greater tubercle) 

Teres Minor of Rotator Cuff

A: Lateral rotation of arm, fused to underlying capsule of the shoulder joint and strengthens it

Teres Minor of Rotator Cuff

O: Scapula (posterior surface)

Teres Minor of Rotator Cuff

I: Humerus (greater tubercle) 

Teres Major 

A: Adduction, extension, medial rotation of arm

Teres Major 

O: Scapula (posterior surface)

Teres Major 

I: Humerus (lesser tubercle) 

Coracobrachialis 

A: Flexion and adduction of arm

Coracobrachialis 

O: Scapula (coracoid process)

Coracobrachialis 

I: Humerus (medial humerus)