UE Muscles Flashcards
Trapezius
O: (1) Medial part of superior nuchal line, (2) Ligamentum nuchae [an expansion of the supraspinous ligament], (3) Thoracic spinous processes, (4) Supraspinous ligament
I: (1) Lateral part of the clavicle, (2) Acromion, (3) Spine of the scapula
I: Motor from spinal portion of accessory nerve (CN XI)
A: (1) As a whole, rotates scapula upward, (2) Upper trap alone: rotates scapula upward, (3) Middle trap retracts [adducts] scapula, (4) Lower trap depresses and upwardly rotates scapula
NOTE: Most superficial layer of superficial back muscles
Nerve runs on deep side of muscle with superficial branch of transverse cervical artery
Latissimus Dorsi
O: (1) Spinous processes of T7-T12, (2) Lumbar aponeurosis [thoracolumbar fascia], (3) Crest of Ilium, (4) Lower 3-4 ribs, (5) Inferior angle of scapula
I: Floor of bicipital groove of humerus (“Lady between 2 majors”)
I: Thoracodorsal nerve (from brachial plexus)
A: (1) Shoulder extension, (2) Shoulder internal rotation, (3) Shoulder adduction, (4) Can also contribute to scapular depression and retraction [adduction]
NOTE: Most superficial layer of superficial back muscles
Levator Scapulae
O: Transverse processes of C1-C4
I: Vertebral border between spine and superior angle of scapula
I: Dorsal scapular nerve
A: (1) Elevation of scapula, (2) downward rotation of scapula
NOTE: Intermediate layer of superficial back muscles.
Rhomboid Minor
O: Spinous processes of C7 and T1
I: Vertebral border of scapula at base of spine
I: Dorsal scapular nerve
A: (1) Downward rotation of scapula, (2) Retraction [adduction] of scapula, (3) Elevation of scapula
NOTE: Intermediate layer of superficial back muscles
Nerve lies on deep surface with deep branch of transverse cervical artery
Serratus Posterior Superior
O: Spinous processes of C7-T2
I: Upper ribs
I: Intercostal nerves T2-T5 (ventral rami)
A: Assists with lifting ribs in inspiration
NOTE: Deepest layer of superficial back muscles
Rhomboid Major
O: Spinous processes T2-T5
I: Vertebral border of scapula below rhomboid minor to the inferior angle
I: Dorsal scapular nerve
A: (1) Downward rotation of scapula, (2) Retraction [adduction] of scapula, (3) Elevation of scapula
NOTE: Intermediate layer of superficial back muscles
Serratus Posterior Inferior
O: Spinous processes T11-L2
I: Lower ribs
I: Intercostal nerves T9-T12 (ventral rami)
A: Unclear, may hold lower ribs down during inspiration
NOTE: Deepest layer of superficial back muscles
Serratus Anterior
O: Digitations from ribs 1-8
I: (1) Vertebral border on costal surface of scapula, (2) Inferior angle of scapula
I: Long thoracic nerve
A: (1) Scapular protraction [abduction], (2) Rotates scapula [glenoid] upward
NOTE: Scapular winging if serratus anterior denervated. Important in scapulohumeral rhythm
Deltoid
O: (1) Lower margin of scapular spine, (2) Acromion, (3) Lower margin of lateral 1/3 of clavicle
I: Deltoid tuberosity of humerus
I: Axillary nerve
A: (1) Acting as a whole, deltoid stabilizes glenohumeral {GH} joint, (2) Acting individually, Anterior fibers: shoulder flexion and horizontal aDDuction, (3) Middle fibers: shoulder ABduction, (4) Posterior fibers: shoulder extension and horizontal abduction
Subscapularis
O: Costal surface of scapula (subscapular fossa)
I: Lesser tubercle of humerus
I: Upper and lower subscapular nerves
A: (1) Stabilizes GH joint, (2) shoulder internal rotation
NOTE: Rotator cuff muscle
Supraspinatus
O: Supraspinous fossa
I: Superior facet of greater tubercle of humerus
I: Suprascapular nerve
A: (1) Stabilizes GH joint, (2) Shoulder abduction, (3) Depresses humeral head during abduction
NOTE: Rotator cuff muscle
Infraspinatus
O: Infraspinous fossa
I: Middle facet of greater tubercle
I: Suprascapular nerve
A: (1) Stabilizes GH joint, (2) Shoulder external rotation
NOTE: Rotator cuff muscle
Teres Minor
O: Lateral border of scapula, above teres major
I: Lower facet of greater tubercle
I: Axillary nerve
A: (1) Stabilizes joint, (2) Shoulder external rotation
NOTE: Rotator cuff muscle
Teres Major
O: Lower lateral border of scapula, as far as inferior angle
I: Medial lip of bicipital groove (“Lady between two majors”)
I: Lower subscapular nerve
A: (1) Shoulder internal rotation, (2) Shoulder adduction, (3) Shoulder extension
Coracobrachi
O: Coracoid process
I: Middle shaft of humerus
I: Musculocutaneous n.
A: (1) Shoulder Flexion, (2) Shoulder adduction
*Muscle belly pierced by musculocutaneous nerve
Biceps Brachii
O: (1) Short Head: Coracoid process, (2) Long head: supraglenoid tubercle (blends with labrum)**
I: Radial tuberosity (radius)
I: Musculocutaneous n.
A: (1) Elbow flexion, (2) Forearm supination, (3) Shoulder flexion
** Tendinous origin of long head runs in fibrous capsule of GH joint (enclosed in synovial membrane,), travel sin bicipital groove, held down by transverse humeral ligament. Two tendons fuse into one muscle belly. Prior to insertion, gives of bicipital aponeurosis medially which fuses with deep fascia. In 10% a third head can be found arising from humerus.
Brachialis
O: Lower, anterior humerus
I: Coronoid process (of ulna)
I: Musculocutaneous n.
A: Elbow flexor (in both supination and pronation)
*Possibly dual innervation from radial nerve
Triceps Brachii
O: (1) Long head: Infraglenoid tubercle, (2) Short head: posterior humerus above spiral groove, (3) Medial head: posterior humerus below the spiral groove (deep)
I: Olecranon process
I: Radial nerve
A: (1) Elbow extension, (2) Long head can adduct and extend shoudler
*Long head runs anterior to teres minor and posterior to teres major muscles
Long and lateral heads form the superficial part of the muscle
Aconeous
O: Lateral epicondyle of humerus I: (1) Lateral surface of olecranon, (2) Lateral ulna I: Radial nerve A: Elbow extension *Posterior compartment
Pectoralis Major
O: (1) Clavicular head: medial 1/3 of clavicle, (2) Sternal head: sternum, upper 6 costal cartilages, (3) Aponeurosis of external oblique
I: Lateral lip of bicipital groove of humerus (clavicular fibers insert lower part of groove, and sternal fibers insert on the higher part of groove)
I: Medial and lateral pectoral nerves
A: Shoulder adduction, shoulder flexion, shoulder internal rotation
Pectoralis Minor
O: Ribs 2-5 (may vary)
I: Coracoid process of scapula
I: Medial and lateral pectoral nerves
A: Protraction of scapula, Scapular depression
Subclavius
O: First rib
I: Clavicle
I: Nerve to subclavius
A: Elevates first rib
Pronator teres
O: Medial epicondyle (common flexor origin), coranoid process of ulna
I: Mid-radius
I: Median nerve
A: Pronation of forearm, weak flexor of elbow
*Median nerve passes between its two heads!!
Flexor carpi radialis
O: Medial epicondyle
I: Base of 2nd metacarpal
I: Median nerve
A: Wrist flexion, wrist radial deviation (along with extensor carpi radialis longus)
Palmaris longus
O: Medial epicondyle I: Palmar aponeurosis I: Median nerve A: Wrist flexion *Absent in 10%!
Flexor carpi ulnaris
O: (1) Medial epicondyle, (2) Posterior border of upper ulna
I: Base of 5th metacarpal, hammate, pisiform
I: Ulnar nerve
A: Wrist flexion, ulnar deviation (along with extensor carpi ulnaris)
Flexor digitorum superficialis
O: 2 heads: (1) Medial epicondyle and coronoid process of ulna, (2) Upper radius
I: 4 tendons insert on either side of the base of middle phalanx, splitting to allow profundus tendon to pass through
I: Median nerve
A: Flexes proximal interphalangeal joint
*Intermediate layer
*Tendons lie in a common synovial sheath under flexor retinaculum that is shared with the flexor digitorum profundus. Middle and ring finger tendons are above little and index finger tendons
Flexor Pollicis Longus
O: (1) Middle radius, (2) Interosseous membrane
I: Base of distal phalanx of thumb
I: Median nerve (anterior interosseous nerve)
A: (1) Flexes distal phalanx of thumb at IP joint, (2) Flexes proximal phalanx of thumb at MCP joint
*Deep layer
Flexor digitorum profundus
O: (1) Upper 3/4 of ulna, (2) interosseous membrane
I: Base of distal phalanx
I: Dual innervation: median nerve to muscle going to digits 2 and 3 (anterior interosseous nerve), Ulnar nerve to muscle going to digits 4 & 5
A: Flexes distal phalanx
*Deep layer
Pronator Quadratus
O: Distal ulna
I: Distal radius
I: Median Nerve
A: Pronation of forearm
Palmaris brevis
O: Hypothenar fascia
I: Skin of ulnar border of the hand
I: Ulnar nerve
A: (1) Moves skin, (2) Improves contour for grip
*Hypothenar eminence
Lumbricals
O: From radial side of tendons of flexor digitorum profundus muscle while leaving common tendon sheath
I: Extensor hood (aponeurosis)
I: (1) Median nerve: lumbricals 1 and 2, (2) Ulnar nerve: lumbricals 3 & 4
A: Flexion of MCP joints with extension of IP joints
*Pass to radial side of MCP joint
Adductor pollicis
O: 2 heads: (1) Transverse from 3rd metacarpal, (2) Oblique from base of metacarpals 1, 2, and 3
I: Base of proximal phalanx of the thumb
I: Ulnar nerve
A: Adduction of the thumb
Palmar interossei
O: Each has 1 head arising from the adjacent metacarpal: (1) 1st interossei from ulnar side of 2nd metacarpal, (2) 2nd interossei from radial side of 4th metacarpal, (3) 3rd interossei from radial side of 5th metacarpal
I: Extensor aponeurosis
I: Ulnar nerve
A: (1) Adduction and flexion at MCP, (2) Extension at IP
Dorsal interossei
O: Each interossei has 2 heads arising from adjacent metacarpal
I: Proximal phalanx and extensor tendon (hood): (1) 1st interossei to radial side of index finger, (2) 2nd interossei to radial side of middle finger, (3) 3rd interossei to ulnar side of middle finger, (4) 4th interossei to ulnar side of ring finger
I: Ulnar nerve
A: (1) Abduction and flexion at MCP, (2) Extension at IP
Abductor Pollicis Brevis
O: (1) Distal border of flexor retinaculum, (2) Trapezium I: Base of proximal phalanx of thumb I: Recurrent branch of median nerve A: Abducts thumb *Thenar eminence
Flexor Pollicis Brevis
O: 2 heads: (1) Superficial head: distal flexor retinaculum and trapezium, (2) Deep head: trapezoid
I: Base of proximal phalanx of thumb
I: (1) Superficial head: recurrent branch of median nerve, (2) Deep head: Ulnar nerve
A: Flexes metacarpophalangeal (MCP) joint
*Thenar eminence
Opponens Pollicis
O: (1) Flexor retinaculum, (2) Trapezium
I: 1st metacarpal
I: Recurrent branch of median nerve
A: Opposition of thumb (movement at carpometacarpal joint)
*Thenar eminence, Covered by flexor and abductor brevis muscles
Abductor Digiti Minimi
O: (1) Pisiform, (2) Adjacent tendons of flexor carpi ulnaris
I: Base of proximal phalanx of little finger
I: Deep branch of ulnar nerve
A: Abducts little finger
*Hypothenar eminence
Flexor Digiti Minimi Brevis
O: (1) Flexor retinaculum, (2) Hamate I: Proximal phalanx I: Deep branch of ulnar nerve A: Flexes MCP joint *Hypothenar eminence
Opponens Digiti Minimi
O: (1) Distal flexor retinaculum, (2) Hook of hamate
I: 5th metacarpal
I: Deep branch of ulnar nerve
A: Opposition of little finger
*Hypothenar eminence, covered by abductor and flexor digit minimi muscles
Brachioradialisl
O: Upper lateral supracondylar ridge of humerus
I: Lateral radius above styloid process
I: Radial nerve
A: (1) Flexion of forearm in neutral position, (2) Supinates pronated forearm, (3) Pronates supinated forearm
Extensor Carpi Radialis Longus
O: Lower lateral supracondylar ridge
I: Base of 2nd metacarpal
I: Radial nerve
A: (1) Wrist extension, (2) Contributes to radial deviation (with flexor carpi radialis)
Extensor Carpi Radialis Brevis
O: Lateral epicondyle (Common extensor origin)
I: Base of 3rd metacarpal
I: Deep branch of radial nerve
A: Wrist extension
Extensor Digitorum
O: Lateral epicondyle (common extensor origin)
I: Extensor Hood
I: Deep branch of radial nerve
A: Extension of all joints of the digits
Explain the mechanism of the extensor aponeurosis (hood)
(A) 3 or 4 tendons pass under retinaculum, (B) Give off intertendinous connections, (C) 1st and 4th tendons joined by extensor indicis tendon and tendon of extensor digiti minimi at MCP joint, (D) At MCP joints, the tendons expand laterally to cover the joint and are joined by the insertions of the lumbricals and interossei, forming the extensor aponeruosis (hood), (E) Aponeurosis splits into 3 bands: 2 lateral and 1 central, (F) Central band inserts on middle phalanx, (G) Lateral bands come together as one to insert on distal phalanx
Extensor Digiti Minimi
O: Lateral epicondyle (common extensor tendon)
I: Extensor hood of 5th finger
I: Deep branch of radial nerve
A: Extension of 5th finger
Extensor Carpi Ulnaris
O: 2 heads: (1) Lateral epicondyle (common extensor tendon), (2) Middle posterior ulna
I: Base of 5th metacarpal
I: Deep branch of radial nerve
A: (1) Wrist extension, (2) Ulnar deviation (with flexor carpi ulnaris)
Supinator
O: (1) Lateral Epicondyle, (2) Radial collateral and annular ligaments, (3) Supinator crest of the ulna
I: Upper radius
I: Deep branch of radial nerve
A: Supinates the forearm
*Radial nerve pierces through supinator muscle belly
Abductor Pollicis Longus
O: (1) Posterior ulna, (2) Posterior radius, (3) Interosseous membrane
I: Base of 1st metacarpal
I: Deep branch of radial nerve
A: Abducts the thumb
Extensor Pollicis Brevis
O: (1) Distal radius, (2) Interosseous membrane
I: Base of proximal phalanx of thumb
I: Deep branch of radial nerve
A: Extends thumb MCP joint
Extensor Pollicis Longus
O: (1) Posterior ulna, (2) Interosseous membrane
I: Distal phalanx of thumb
I: Deep branch of radial nerve
A: Extends thumb
*Origin lies between abductor pollicis longus and extensor pollicis brevis
Extensor Indicis
O: Posterior distal ulna
I: Extensor hood of index finger
I: Deep branch of radial nerve
A: Extension of index finger
