Muscles of the Upper Extremity Flashcards
Transverse Carpal Ligament (Flexor Retinaculum)
Insertion: (Radial Side) - Tubercle of scaphoid and the crest of the trapezium; (Ulnar Side) - Pisiform and Hook of the Hamate
Brachioradialis
Origin: Lateral Supracondylar Ridge of Humerus Insertion: Styloid of the radius Function: Flexes forearm at the elbow Nerve: Radial Nerve (C5-C6) Orientation:
Extensor Carpi Radialis Brevis
Origin: Lateral Epicondyle of Humerus Insertion: Base of the 3rd metacarpal Action: Extends and radially deviates hand at wrist Nerve: Radial Nerve (C6-C7) Orientation:
Extensor Carpi Radialis Longus
Origin: Distal Lateral Supracondylar ridge of the Humerus
Insertion: Base of the 2nd metacarpal
Action: Extends and radially deviates hand at wrist
Nerve: Radial Nerve (C6-C7)
Orientation:
Common Extensor Tendon
Origin: Lateral Epicondyle of Humerus
Insertion: Extensor Carpi Radialis Brevis, Extensor Digiti Minimi, Extensor Digitorum, Extensor Carpi Ulnaris
Supinator
Origin: Lateral Epicondyle of Humerus
Insertion: Anterior Surface of Proximal Radius
Action: Supinates the forearm
Nerve: Radial Nerve
Anconeus
Origin: Lateral Epicondyle of Humerus
Insertion: Posterior Olecranon of Ulna
Action: Extends forearm at the elbow
Nerve: Radial Nerve (C7-C8)
Biceps Brachii
Origin: (Long Head): Supraglenoid Tubercle of Scapula; (Short Head): Coracoid Process of Scapula
Insertion: Radial Tuberosity and Bicipital Aponeurosis of the forearm
Action: Flexes and supinates forearm at the elbow
Nerve: Musculocutaneous Nerve (C5,C6)
Orientation: Fusiform
Pronator Teres
Origin: (Humeral Head): Medial Epicondyle of Humerus and Supracondylar Ridge (Ulnar Head): Medial Side of Coronoid Process
Insertion: Middle Lateral Surface of Radius
Action: Pronates and flexes forearm at the elbow
Nerve: Median Nerve (C6-C7)
Common Flexor Tendon
Origin: Medial Epicondyle of Humerus
Insertion: Pronator Teres, Flexor Carpi Radialis, Palmaris Longus, Flexor Digitorum Superficialis, Flexor Carpi Ulnaris
Flexor Carpi Ulnaris
Origin: Medial Epicondyle of Humerus
Insertion: Pisiform, Hook of Hamate, Base of 5th Metacarpal
Action: Flexes and ulnar deviates hand at wrist
Nerve: Ulnar Nerve (C8-T1)
Abductor Pollicis Longus
Origin: Posterior surface of radius and ulna; interosseous membrane
Insertion: Base of First metacarpal and trapezium
Action: Abducts and extends thumb
Nerve: Radial Nerve (Posterior interosseous nerve)
Extensor Pollicis Brevis
Origin: Dorsal shaft of radius and ulna; interossesous membrane
Insertion: Base of proximal (brevis) and distal (longus) phalanx
Action: Extends thumb
Nerve: Radial Nerve (Posterior interosseous nerve)
Triceps (Long Head)
Origin: Infraglenoid Tubercle of Scapula
Insertion: Posterior Olecranon of Ulnar
Action: Extends the forearm at the elbow
Nerve: Radial Nerve (C7-C8)
Triceps (Medial Head)
Origin: Inferior 2/3 of posterior Humerus
Insertion: Posterior Olecranon Process of Ulna
Action: Extends the forearm at the elbow
Nerve: Radial nerve (C7-C8)
Triceps (Lateral Head)
Origin: Proximal portion of posterior humerus, superior to radial groove
Insertion: Posterior olecranon process of ulna
Action: Extends the forearm at the elbow
Nerve: Radial Nerve (C7-C8)
Deltoid (Anterior, Middle Heads)
Origin: Anterior (clavicular) head: anterior surface of the lateral clavicle.
Middle (acromial) head: acromion process and spine of the scapula.
Insertion: Deltoid tuberosity of the humerus.
Action:
Anterior Head: Flexes the arm at the (glenohumeral) shoulder joint. Medially rotates the arm at the (glenohumeral) shoulder joint.
Middle Head: Abducts the arm at the (glenohumeral) shoulder joint.
Nerve: Axillary Nerve (C5-C6)
Orientation: Multipennate
Deltoid (posterior head)
Origin: Spine of scapula. Insertion: Deltoid tuberosity of Humerus Action: Laterally rotates the arm at the shoulder (glenohumeral) joint. Extends the arm at the shoulder (glenohumeral) joint. Nerve: Axillary Nerve (C5-C6) Orientation: Multipennate
Pectoralis Major
Origin: Sternal end of clavicle; sternum; cartilage of ribs (1-6) and aponeurosis of external oblique muscle
Insertion: Fibers converge to insert by a short tendon into greater tubercle of humerus
Action: Prime mover of arm flexion; rotates arm medially; addicts arm
Nerve: Lateral and medial pectoral nerves (C5-C8 and T1)
Orientation: Convergent
Pectoralis Minor
Origin: Anterior surfaces of the sternal ends of the ribs
Insertion: Coracoid process of scapula
Action: Draws scapula forward and downward (It also elevates ribs if origin and insertion are reversed)
Nerve: Medial Pectoral nerve (C8-T1)
Orientation: Convergent
Trapezius
Origin: Medial superior nuchal line and external protuberance of occipital bone, ligamentum nuchae, and spinous process of C7-T12
Insertion: Lateral clavicle, acromion of scapula, spine of scapula
Action:
Upper Fibers - elevate and upwardly rotate scapula; extend neck
Middle Fibers - adduct (retract) scapula
Lower Fibers - depress and help upper fibers upwardly rotate scapula
Nerve: Accessory Cranial nerve (XI) (C3-C4)
Orientation:
Levator Scapulae
Origin: Transverse processes of C1-C4
Insertion: Medial border of the scapula; superior to the spine
Action: Elevates and adducts scapula
Nerve: Cervical Spinal nerves and dorsal scapular nerves (C3-C5)
Orientation:
Supraspinatus
Origin: Supraspinous fossa of scapula
Insertion: Superior aspect of greater tubercle of humerus
Action: Helps the deltoid muscle initate abduction of the arm at the shoulder (glenohumeral) joint. Helps stabilize the shoulder by drawing the humerus toward the glenoid fossa
Nerve: Suprascapular Nerve (C5-C6)
Orientation:
Teres Major
Origin: Lower lateral border and inferior angle of scapula
Insertion: Medial lip of intertubercular (bicipital) groove of the anterior humerus
Action: Adducts the arm at the shoulder joint. Medially rotates the arm at the shoulder joint. Extends the arm at the shoulder joint
Nerve: Lower Subscapular Nerve (C5-C7)
Orientation:
Teres Minor
Origin: Middle part of the lateral (axillary) border of the scapula
Insertion: Inferior aspect of greater tubercle of humerus
Action: Laterally rotates the arm at the shoulder joint. Weakly adducts the arm at the shoulder joint. Helps stabilize the shoulder by drawing the humerus toward the glenoid foss of the scapula.
Nerve:
Orientation:
Subscapularis
Origin: Subscapular foss of the scapula
Insertion: Lesser tubercle of humerus
Action: Medially rotates the arm at the shoulder joint
Nerve: Upper and lower Subscapular Nerves (C5-C7)
Orientation: Multipennate
Rhomboid Major
Origin: Spinous process of T2-T5 Vertebrae
Insertion: Medial border of scapular inferior to spine
Action: Retracts and elevates the medial border of the scapula white it downwardly rotates the lateral angle
Nerve: Dorsal Scapular Nerve (C5)
Orientation: Straight
Rhomboid Minor
Origin: Spinous process of C7-T1
Insertion: Medial border of scapula superior to spine
Action: Retracts and elevates the medial border of the scapular while it downwardly rotates the lateral angle
Nerve: Dorsal Scapular Nerve 9C5)
Orientation: Straight
Latissimus Dorsi
Origin: Indirect attachment via thoracolumbar fascia into spines of lower six thoracic vertebrae; lumbar vertebrae; lower 3 to 4 ribs; and iliac crest
Insertion: spirals around teres major to insert in floor of intertubercular sulcus of humerus
Action: Prime mover of arm extension; and medial rotation at shoulder
Nerve: Thoracodorsal (C6-C8)
Orientation:
External Intercostals
Origin: Inferior border of rib above Insertion: Superior border of rib below Action: Pulls Ribs toward one another to elevate rib cage Nerve: Intercostal Nerves Orientation:
Internal Intercostals
Origin: Superior border of rib below
Insertion: Inferior border (costal groove) of rib above
Action: Draws ribs together and depresses rib cage
Nerve: Intercostal nerves
Orientation:
