Muscle Anatomy Upper Extremity Upper Arm Muscle 1. Deltoid 2. Biceps Brachii Action a. Anterior : Flexion Origin a. Lateral 3 of clavicle b. Middle: abduction of arm b. Acromion process c. Posterior: extension of arm c. Scapular Spine a. flexion of the elbow a. long head: supraglenoid tubercle b. coracoid process of scapula Coracoid process Radial tuberosity Anterior surface of humerus Coronoid process Ulnar tuberosity Olecranon rd b. flexion of shoulder 3. Coracobrachialis Adducts the arm 4. Brachialis 5. Anconeus Flexion of elbow (picking up a bucket) Extension of the forearm 6. Triceps Brachii Extension of the forearm Insertion Deltoid Tuberosity Lessor tuberosity of humerus Adducts the arm Lateral epicondyle of humerus a. long head: infraglenoid tubercle b. lateral head: radial sulcus Extends shoulder c. medial head: radial sulcus 7. Subscapularis Rotates the humerus Subscapular fossa Lesser tubercle of humerus 8. Supraspinatus Abducts the arm Supraspinous fossa Greater tubercle of humerus 9. Infraspinatus Rotation of humerus Infraspinous fossa Greater tubercle of humerus 10. Teres Minor Lateral rotation of arm Lateral border of scapula Greater tubercle of humerus 11. Teres Major a. Adduct humerus Inferior angle of scapula Intertubercular sulcus/groove of humerus b. Medial rotation of humerus Olecranon c. Depress shoulder Lower Arm Flexors Muscle 1. Flexor Carpi Ulnaris 2. Palmaris Longus 3. Flexor Carpi Radialis 4. Flexor Digitorum Superficialis 5. Flexor Digitorum Profundus 6. Flexor Pollicis Longus Action Flexion of the wrist Adduction of the wrist Flexion of the wrist Flexion of the wrist Abduction of the wrist Flexion of the fingers Flexion of the fingers Origin Medial Epicondyle of Humerus Medial Epicondyle of Humerus Medial Epicondyle of Humerus Medial Epicondyle of Humerus Anterior surface of the ulna Flexion of the thumb 7. Pronator Teres Pronation of forearm 8. Pronator Quadratus Pronates the forearm Insertion Pisiform and hook of hamate Aponeurosis 2nd metacarpals Middle Phalanges Distal phalanges Distal Phalanx of thumb Medial Epicondyle of Humerus Anterior medial surface of the ulna Lower Arm Extensors Middle body of radius Anterior lateral surface of the radius Muscle 1. Brachioradialis 2. Extensor Carpi Radialis Brevis 3. Extensor Carpi Radialis Longus 4. Extensor digitorum Action Origin Flexion of the elbow, supination, (thumbs up) Extension of the wrist Extension of the wrist Extension of the four digits 5. Extensor Carpi Ulnaris Extension of the wrist 6. Extensor Digiti Minimi Extension of the fifth digit 7. Abductor Pollicis Longus Abduction of the thumb 8. Extensor Pollicis Brevis Extension of the thumb 9. Extensor Indicis Extension of the 2nd digit 10. Extensor Pollicis Longus Extention of the thumb Insertion Lateral supracondylar ridge of humerus Lateral epicondyle of humuerus Lateral supracondylar ridge of humerus Lateral epicondyle of humerus Lateral epicondyle of humerus Lateral epicondyle of humerus Interosseus membrane between the radius and ulna Interosseus membrane between the radius and ulna Distal ulna Distal radius, styloid process Interosseus membrane between the radius and ulna Distal phalanx of the thumb 2nd metacarpal 3rd metacarpal Medial four digits 5th metacarpal (pinky) 5th digit (pinky) 1st Metacarpal (thumb) Proximal phalanx of the thumb Index finger phalanges Intrinsic Hand Muscles Muscle Action Origin Insertion 1. Opponens Pollicis Flexion of the thumb Trapezius Metacarpal of the thumb 2. Abductor Pollicis Brevis Abduction of the thumb Scaphoid and Trapezius Thumb: Proximal phalanx 3. Flexor Pollicis Brevis Flexion of the thumb Trapezium Thumb: Proximal phalanx 4. Opponens digiti minimi Pinches pinky to thumb Hamate 5th metacarpal 5. Abductor digiti minimi Abducts 5th digit Pisiform Proximal phalanx 5th digit 6. Flexor digiti minimi Flexion 5th digit Hamate Proximal phalanx 5th digit 7. Lumbricals Flexion and extension of the metacarpophalangeal joint Flexor digitorum profundus Extensor tendons
