MUSCLE ORIGIN INSERTION ACTION NERVE Pectoralis Major medial half of clavicle; Sternum; upper six costal cartilages Lateral lip of intertubercular groove of horizontal adduction Medial and lateral pectoral nerves Pectoralis Minor External surfaces of ribs 3-5 Coracoid the Raises ribs in forced inspiration; draws forward and downward Medial and lateral pectoral nerves Trapezius Latissimus Dorsi Levator Scapulae External occipital protuberance; ligamentum nuchae; Spinous processes and surpraspinous ligaments of C7 and all thoracic vertebrae Spinous processes of lower six thoracic vertebrae; Lumbar vertebrae, sacral vertebrae, supraspinous ligament; Posterior part of iliac crest; lower three or four ribs; Inferior angle of the Posterior tubercles of transverse processes of C1-C4 Lateral third of clavicle; acromion and crest of spine of ; Inner/medial aspect of the spine of the Bottom of intertubercular groove Superior angle of Shrugging the shoulders Extends and hyperextends the arm, drawing shoulder downward and backward; Extends, adducts and medially rotates the arm Elevates (synergist) Accessory (eleventh cranial) Thoracodorsal (C6-C8) Dorsal r
Rhomboid Major Spines of thoracic vertebrae 2-5; Supraspinous ligament Medial border of the below the spine Retracts and stabilizes Dorsal r Rhomboid Minor Serratus Spines of c7 and T1; Lower part of ligamentum nuchae Medial border of the at the root of spine Retracts and stablizes Dorsal r Outer surface of first 8-9 ribs medial border of Holds in place against posterior thoracic wall Long Thoracic Deltoid ROTATOR CUFF (SITS) border and superior lateral third of clavicle; Lateral border of the acromion process; Lower border of the crest of the spine of the r Deltoid tuberosity Main action: abducts arm; synergist: flexes and medially rotates arm, Extends and laterally rotates arm Axillary (C5, C6) Supraspinatus (rotator cuff) Supraspinous fossa of Superior facet of greater Hyperextension of the arm Suprar nerve
Infraspinatus (rotator cuff) Infraspinous fossa of Middle facet of the greater Lateral rotation of the arm, synergist to abduction of arm Suprar nerve (C5, C6) Teres Minor (rotator cuff) Upper 2/3 of the posterior the lateral border of the Lower facet of the grater Laterally rotates arm (synergist); weak synergist to adduction of arm Axillary Subris (rotator cuff) Subr fossa on the anterior Lesser Internal rotation of the arm Upper and lower subr nerves (C5, C6) Teres Major Lower third of the posterior the lateral border of the r, near inferior angle Medial lip of intertubercular groove Syngergist to latissimus dorsi: Adducts arm, extends arm, medially rotates arm Lower subr nerve
Brachialis of lower half of Coronoid ulna; ulna tuberosity Primary forearm flexor Musculocutaneous Biceps Brachii Two heads: Supraglenoid scapulus & coracoid tuberosity; bicipital aponeurosis into deep fascia on medial side of forearm Supinates forearm in flexion; weak forearm flexor Musculocutaneous Coracobrachialis Tip of coracoid Middle third of the medial border of Flexor of at shoulder joing Musculocutaneous Triceps Brachii Long head: infraglenoid ; Lateral head: upper half of posterior ; Medial head: posterior lower half of (buried) Posterior part of olecranon ulna Extends forearm; long head aids in addution if arm is abducted
Superficial GROUP Pronator Teres (superficial group) Flexor carpi radialus (superficial group) Humeral head- medial supracondylar ridge and medial ; Ulnar headmedial border of the coronoid prrocess of ulna Medial the through common tendon (flexor pronator tendon) Middle of lateral surface of the radius (pronator tuberosity) Front of the bases of the second and third bones Pronates and flexes forearm Flexes hand; radial deviation Median nerve Median nerve Palmaris Longus (superficial group) Medial the through common tendon (flexor pronator tendon) Front of flexor retinaculum and apex of palmar aponeurosis Flexes the hand; makes a tight fist Median nerve Flexor carpi ulnaris (superficial group) Humeral head- medial ; Ulnar headmedial margin of olecranon ulna, dorsal border of shaft of ulna Pisiform bone; hook of hamate; base of fifth Flexes hand; ulnar deviation Ulnar nerve
Flexor Digitorum Superficialis (Intermediate grp) Medial through common tendon; medial margin of coronoid ulna; anterior shaft of radius Four tendons split and connect at middle phalanges of four fingers Primary: flexion of digits. Flexes carpal region, MCPs & PCPs of digits 2-5. Median nerve Flexor Digitorum Profundus (deep) Upper anterior & medial shaft of ulna and medial coronoid process, membrane Front of base of distal phalanges of fingers 2-5 Flexes distal phalanges (DIPS). Synergist to MCPs & PIPs Anerior Interosseus/Ulnar (digit flexion backup for median nerve) Flexor Pollicis Longus Middle of anterior shaft of radius, membrane, Palmar aspect of base of distal phalanx of thumb Flexes the thumb (branch of median) Three muscles in compartment of forearm but no action on digits:
Pronator Quadratus distal part of shaft of ulna Lower portion of anterior shaft of radius, distal part of lateral border of radius Pronates forearm and hand; works with Pronator teres for full pronation. (branch of median) Supinator Lateral ; supinator crest and foss of ulna Posterior and lateral surfaces of upper third of radius suppinates forearm; antagonist of pronator teres and pronator quadratus; supinator when in extension, syngergist in flexion (because origin off lateral condyle) Brachioradialis Upper 2/3 of lateral supracondylar ridge of Base of styloid process and lateral surface of radius Flexes forearm (synergist to brachialis) (elbow flexion backup) Posterior Compartment of forearm Extensor Carpi is (Brevis3 & Longus2) Lateral supracondylar ridge and Dorsal surface of 2nd and 3rd s extends hand; synergist in radial deviation with flexor carpi radialis; antagonist to FCR for extension/flexion
Extensor Carpi Ulnaris Common tendon attached to lateral Dorsal surface of base of 5th bone Extends hand; synergist in ulnar deviation with flexor carpi ulnaris (because origin off lateral condyle) Extensor Digitorum Communis Common tendon attached to lateral Lateral and dorsal surfaces of all phalanges of four fingers Extends the fingers and wrist; extension expansion joint at distal phalanges (because origin off lateral condyle) Extensor Indicis Posterior ulna and adjacent part of membrane Extensor expansion on dorsal surface of index finger Extends index finger Extensor Digiti Minimi Common tendon attached to lateral Dorsal surface of base of first fifth finger Extends fifth finger (pulls out of opposition)
Abductor Pollicis Longus Dorsal shaft or radius, ulna, membrane Dorsal surface of base of first bone Abducts thumb & wrist Extensor Pollicis Brevis Dorsal radius, adjacent part of membrane Base of thumb Extends thumb Extensor Pollicis Longus Abductor pollicis Brevis (thenar eminence) Flexor Pollicis Brevis (thenar eminence) Middle third of dorsal ulna, membrane Tubercle of scaphoid, trapezium, flexor retinaculum Flexor retinaculum and trapezium, first bone Base of distal thumb lateral aspect of base of thumb Medial and lateral aspect of base of thumb Extends thumb Abducts thumb ( with Abductor Pollicis Longus) and opposes thumb to other fingers Flexes MCP joint of thumb, opposes thumb Median Median/Ulnar Opponens Lateral border Rotates thumb into Pollicis (thenar Flexor of first opposition, primary eminence) retinaculum, thumb opposer; Median bone, wraps separates us from trapezium around entire animals lateral border Adductor Medial side of adducts thumb Ulnar!
Pollicis Abductor Digiti Minimi (Hypothenar eminence) Flexor Digiti Minimi (Hypothenar eminence) Opponens Digiti Minimi (Hypothenar eminence) 2 & 3 s, capitate, trapezoid Pisiform bone, tendon of flexor carpi ulnaris flexor retinaculum, hook of hamate Flexor retinaculum, hook of hamate Lumbricales JUST KNOW: Synergist to PIP & MCP function Palmar Palmer Interossei (PAD) s: ADducts Dorsal Interossei (DAB) digits between 2-3, 3-4, 4-5; Dorsal surface between s; ABducts between 2-3 and 3-4 digits thumb Medial side of fifth finger Medial side of base of fifth finger Whole length of medial border of fifth bone Abducts fifth finger Flexes fifth finger (extrinisic muscles, Flexor Digitorum Profundus/Superficialis are stronger flexers) rotates fifth bone, flexing fifth finger Ulnar Ulnar Ulnar