Shoulder region

• Bones• Joints• Muscles• Vessels & Nerves

Classifications of muscles that move the shoulder

• A. muscles connecting scapula to humerus• B. muscles connecting trunk to scapula• C. muscles connecting trunk to humerus

Biceps & Triceps tendons

A. muscles connecting scapula to humerus

1. Supraspinatus2. Infraspinatus3. Teres minor4. Subscapularis5. Teres major6. Coracobrachialis7. Deltoid

Short muscles

• Function:abduction

Subscapularis

• Function: Int. rotation

Rotator Cuff

• Rotator cuff function:

• only 25% of the humeral head is in contact with the glenoid fossa.

• The rotator cuff muscles compress and depress the humeral head within the glenoid fossa.

Rotator Cuff Disease photo

Quiz

supraspinatus

subscapularisinfraspinatus teres minor

Teres major• Function:

adduction of humerusmed rotator

• Why medial?

• Origin:– Inf angle of scapula

• Insertion:– Med lip of groove

• Actions:– Internal rotation and

adduction of arm

Coracobrachialis

• Function:flex & adductthe shoulder joint

Deltoid

• Origin:– Clavicle, scapula

• Insertion:– Deltoid tuberosity of

humerus

• Actions:– Abduction– Anterior deltoid: internal

rotation– Posterior deltoid:

external rotation

Classifications of muscles that move the shoulder

• A. muscles connecting scapula to humerus• B. muscles connecting trunk to scapula• C. muscles connecting trunk to humerus

B. muscles connecting trunk to scapula

1. Serratus anterior2. Levator scapula3. Rhomboid major4. Rhomboid minor5. Trapezius6. Pectoralis minor

Serratus Anterior

• Origin:– Ribs

• Insertion:– Medial border of

scapula

• Actions:– Protraction and

rotation of scapula

Winged scapula

Levator scapula

• Origin:– Cervical vertebrae

• Insertion:– Scapula

• Action:– Elevation of the scapula

Rhomboid major and minor

• Origin:– Cervical and Thoracic

vertebrae

• Insertion:– Scapula

• Actions:– Retraction– Elevation

Trapezius

• Origin:– Occipital bone of skull,

cervical and thoracic vertebrae

• Insertion:– Clavicle and Scapula

• Actions:– Elevation– retraction

Pectoralis Minor

• Origin:– Ribs

• Insertion:– Coracoid process of

scapula

• Action:– Depression of scapula

Depression of scapula

Classifications of muscles that move the shoulder

• A. muscles connecting scapula to humerus• B. muscles connecting trunk to scapula• C. muscles connecting trunk to humerus

C. muscles connecting trunk to humerus

• Pectoralis major• Latissimus dorsi

Pectoralis Major

• Origin:– Clavicle, sternum, upper

ribs

• Insertion:– Crest of greater tubercle

and lat lip

• Action:– Add, med rotation

Latissimus Dorsi

• Origin:– Vertebrae, sacrum,

ilium

• Insertion:– Medial lip

• Actions:– Adduction and med

rotation of humerus

Latissimus Dorsi if humerus is fixed

• Covering th front and back of the trunk.• The pectoralis major and latissimus dorsi both adduct and medially rotate the

Humerus.• Lower edge of the pectoralis major muscle on rib 7 = upper edge of the latissimus dorsi

on vertebra T7.

Shoulder Girdle Movements