Shoulder

MUSCLES SHOULDER

Shoulder Muscles

Deltoid

Supraspinatus

Infraspinatus

Smaller Round

Bigger Round

Subscapular

1. DELTOIDE

Proximal Insertion: 1/3 lateral to anterior border of scapula, acromion and spine
Distal Insertion: Deltoid tuberosity & #8211; humerus
Innervation: Axillary Nerve (C5 and C6)
Action: Arm Abduction, assists in Flexion, Extension, Lateral and Medial Rotation, Arm Flexion and Horizontal Extension movements. Shoulder Joint Stabilization

2. SUPRAESPINHAL

Medial Insertion: Supraspinatus fossa & #8211; shoulder blade
Lateral Insertion: Upper facet of the greater humerus tuber
Innervation: Suprascapular Nerve (C5 and C6)
Action: Arm Abduction

3. INFRASTRUCTURE

Medial Insertion: Infrared Spinal Fossa
Lateral Insertion: Middle facet of the greater humerus tuber
Innervation: Suprascapular Nerve (C5 and C6)
Action: Lateral Arm Rotation

4. SMALLER ROUND

Medial Insertion: 2/3 superior of the lateral edge of the scapula
Lateral Insertion: Lower facet of greater humerus tuber
Innervation: Axillary Nerve (C5 and C6)
Action: Lateral Rotation and Arm Adduction

5. LARGER ROUND

Medial Insertion: 1/3 lower than lateral edge of scapula and lower angle of scapula
Lateral Insertion: Crest of the lower humerus tuber
Innervation: Lower Subscapular Nerve & #8211; Posterior fascicle of the brachial plexus (C5 and C6)
Action: Medial Rotation, Adduction and Extension of Shoulder Joint

6. SUBSCAPULAR

Medial Insertion: Subscapular Fossa
Lateral Insertion: Smaller tuber
Innervation: Upper and Lower Subscapular Nerve & #8211; Posterior fascicle (C5 and C6)
Action: Medial Rotation and Arm Adduction

ROTATOR CUFF:

The primary function of this group is to hold the humeral head against the glenoid cavity, strengthen the joint capsule and actively resist and unwanted dislocation of the humeral head anteriorly, posteriorly, and superiorly. The following muscles are part of the rotator cuff:

SUPRAESPINHAL

INFRASTRUCTURE

ROUND LOWER

Subscapular

SHOULDER MUSCLES
Posterior view