Our Amazing Arms & Shoulders

Phalanges Metacarpels Carpels

Clavicle (collar bone) Humerus Scapula (shoulder blade) Ulna Radius

Supination Pronation 4= Radius 5=Ulna

Scapula Anatomy 4 Joints of Shoulder Glenoid Cavity & Humerus Acromioclavicular Clavicle & Sternum Scapula & Posterior ribs

Rotator Cuff Muscles 1/ Subscapularis – humerus internal rotation 2/ Supraspinatus – humerus abduction 3/ Infraspinatus – humerus external rotation 4/ teres minor – adduction & ex rotation 5/ teres major – internal rotation

Deltoid Muscles Posterior Origin – scapula Lateral Origin – acromion Anterior Origin – clavicle Insertion – lateral humerus Posterior Action – extension, horizontal abduction & lateral rotation of humerus Lateral Action – abduction of humerus to 90° Anterior Action – flexion, horizontal adduction & medial rotation of humerus

Latissimus Dorsi Origin – T7 to iliac crest Insertion – rotates 180° before inserting on inside of humerus Action – adduction & extension of humerus Action when arms are fixed – opens the chest by drawing it forward

Rhomboids – Major & Minor Origin – spinous processes Insertion – vertical border of scapula Action – Retraction & downward rotation of scapula

Trapezius Origin- extends from lower thoracic to base of skull Insertion – scapula & clavicle Upper Action – elevates & rotates scapula Middle Action – adducts scapula Lower Action – scapula depression

Muscles that act on the scapula Anterior Muscles

Pectoralis Minor Origin - 3rd, 4th & 5th Ribs Insertion– coracoid process of scapula Action – protraction, depression & downward rotation of scapula

Serratus Anterior Origin – 9 ribs Insertion – medial scapula Action – protraction & upward rotation of scapula + stabilize scapula on ribcage

Muscles that act on the scapula Posterior Muscles

Trapezius Origin- extends from lower thoracic to base of skull Insertion – scapula & clavicle Upper Action – elevates & rotates scapula Middle Action – adducts scapula Lower Action – scapula depression

Rhomboids – Major & Minor Origin – spinous processes Insertion – vertical border of scapula Action – Retraction & downward rotation of scapula

Levator Scapule Origin – c1-4 transverse processes Insertion – medial border of scapula Action – elevation & downward rotation of scapula

Muscles that act on the humerus Muscles of rotation

Rotator Cuff Muscles 1/ Subscapularis – humerus internal rotation 2/ Supraspinatus – humerus abduction 3/ Infraspinatus – humerus external rotation 4/ teres minor – adduction & ex rotation 5/ teres major – adduction & ex rotation

Deltoid Muscles Posterior Origin – scapula Lateral Origin – acromion Anterior Origin – clavicle Insertion – lateral humerus Posterior Action – extension, horizontal abduction & lateral rotation of humerus Lateral Action – abduction of humerus to 90° Anterior Action – flexion, horizontal adduction & medial rotation of humerus

Pectoralis Major Origin – sternum Insertion – inside front humerus Action – adduction, horizontal adduction & medial rotation of humerus

Muscles that act on the humerus Muscles of abduction & adduction

Latissimus Dorsi Origin – T7 to iliac crest Insertion – rotates 180° before inserting on inside of humerus Action – adduction & extension of humerus Action when arms are fixed – opens the chest by drawing it forward

Deltoid Muscles Posterior Origin – scapula Lateral Origin – acromion Anterior Origin – clavicle Insertion – lateral humerus Posterior Action – extension, horizontal abduction & lateral rotation of humerus Lateral Action – abduction of humerus to 90° Anterior Action – flexion, horizontal adduction & medial rotation of humerus

Pectoralis Major Origin – sternum Insertion – inside front humerus Action – adduction & medial rotation of humerus

Biceps Brachii Origin Short head – coracoid process Origin Long Head – top of glenoid Insertion – radius Action – flexes elbow and humerus, supinates forearm

Triceps Brachii 3 heads (long, lateral & medial) Origin – scapula (long head) & humerus (lateral & medial) Insertion – olecranon process of Ulna Action – extension of elbow & humerus (long head)

Muscles that act on the humerus Internal Rotation Anterior deltoid Pectoralis Major Subscapularis Teres Major Latissimus Dorsi External Rotation Infraspinatus Teres Minor Posterior Deltoid

Muscles that act on the humerus Adduction Biceps Brachii Pectoralis Major Teres Major Latissimus Dorsi Triceps Abduction Supraspinatus Lateral Deltoid Biceps Brachii

Muscles that act on the humerus Extension Latissimus dorsi Teres major Posterior deltoid Infrspinatus Teres Minor Triceps – long head Pectoralis Major – sternal head Flexion Anterior Deltoid Pectoralis Major – clavicular head Biceps Brachii