Muscles of the Upper Limb

shoulder muscles (scapulohumeral region)

deltoid

supraspinatus

infraspinatus

teres minor

subscapularis

teres major

are innervated by the brachial plexus

deltoid

shoulder muscle that originates from the clavicle, and spine + acromion process of scapula, inserts on deltoid tuberosity of the humerus

abducts arm

innervated by axillary nerve

rotator cuff muscles

surround the joint capsule of the shoulder

supraspinatus, infraspinatus, teres minor, and subscapularis

supraspinatus

rotator cuff muscle that originates from the supraspinous fossa of scapula and inserts on the greater tubercle of humerus

abducts the shoulder

infraspinatus

rotator cuff muscle that originates from the infraspinous fossa of the scapula and inserts on the greater tubercle of the humerus

rotates laterally

teres minor

rotator cuff muscle that originates from the lateral border of the scapula and inserts on the greater tubercle of the humerus

laterally rotates the shoulder

innervated by axillary nerve

subscapularis

rotator cuff muscle that originates from the subscapular fossa and inserts on the lesser tubercle of the humerus

medially rotates shoulder

teres minor

shoulder muscle that originates from the lateral border of the scapula and inserts on the intertubecular groove of the humerus

adducts, medially rotates and extends shoulder

musculocutaneous nerve

innervates the anterior side of the arm

median nerve

innervates the anterior side of the forearm and hand

ulnar nerve

innervates the anterior side of the forearm and hand

radial nerve

innervates the posterior side of the arm and forearm

anterior muscles of arm

innervated by musculocutaneous nerve

muscles are biceps brachii, brachialis, and coracobrachialis

biceps brachii

anterior arm muscle that is innervated by the musculocutaneous nerve

has two separate heads (short and long), long head origin is supraglenoid tubercle of scapula, and short head origin is coracoid process of scapula, insertion is radial tuberosity of radius

flexes and supinates the elbow

brachialis

anterior arm muscle innervated by the musculocutaneous nerve

is deep to biceps brachii, origin is anterior shaft of the humerus, inserts on the ulnar tuberosity

is a pure flexor

coracobrachialis

anterior arm muscle innervated by the musculocutaneous nerve

origin is coracoid process of the scapula, inserts on the shaft of the humerus,

is a flexor and adductor of the shoulder

posterior muscles of the arm

are innervated by the radial nerve

only muscle is triceps brachii that has three heads (long, lateral, and medial), origin is humeral shaft for the medial and lateral heads, origin is infraglenoid tubercle of scapula for the long head, they all insert on the olecranon process of the ulna

superficial anterior muscles of the forearm

mostly innervated by median nerve (not flexor carpi ulnaris), all have an origin of the medial epicondyle of humerus

flexor carpi ulnaris

flexor carpi radialis

palmaris longus

pronator teres

flexor digitorum superficialis

brachioradialis

flexor carpi ulnaris

only superficial anterior forearm muscle innervated by ulnar nerve and not the median nerve

origin is medial epicondyle of humerus, insertion is base of M5 (metacarpal 5)

flexes and adducts wrist

flexor carpi radialis

superficial anterior forearm muscle that originates from the medial condyle of the humerus and inserts on M2 and M3, crosses over the radius

flexes wrist and abducts

palmaris longus

superficial anterior forearm muscle innervated by the median nerve that originates from the medial epicondyle of the humerus and inserts on the palmar aponeurosis (10% of people don’t have this muscle)

pure wrist flexor

pronator teres

superficial anterior forearm muscle innervated by the median nerve, origin is medial epicondyle of humerus and insertion is the shaft of the radius

pronates the forearm

flexor digitorum superficialis

superficial anterior forearm muscle innervated by the median nerve, origin is medial epicondyle of the humerus and insertion is middle phalanges of digits 2-5

flexes the digits and the wrist

flexor retinaculum

band of CT on the wrist covering all tendons except palmaris longus

brachioradialis

superficial anterior forearm muscle innervated by the RADIAL nerve and not the median nerve, origin is NOT medial epicondyle of the humerus, it is the distal humerus crest, the insertion is the distal radius, migrates to the front during development

flexes the elbow

deep anterior forearm muscles

are mostly innervated by the median nerve ( origin is forearm bones)

flexor digitorum profundus

flexor pollicis longus

pronator quadratus

flexor digitorum profundus

deep anterior forearm muscle

is deep to flexor digitorum superficialis, origin is a forearm bone and insertion is distal phalanges of digits 2-5

the medial side is innervated by the ulnar nerve, but the rest innervated by median

flexes the digits and wrist

flexor pollicis longus

deep anterior forearm muscle innervated by the median nerve that originates from forearm bones and inserts on distal phalynx

flexes the thumb

pronator quadratus

deep anterior forearm muscle innervated by the median nerve, origin is forearm bones and insertion is the radius

pronates the radius

superficial posterior muscles of the forearm

innervated by the radial nerve and origin is lateral epicondyle

extensor carpi ulnaris

extensor carpi radialis longus

extensor carpi radialis brevis

extensor digitorum

extensor digiti minimi

extensor carpi ulnaris

superficial posterior forearm muscle innervated by the radial nerve, origin is lateral epicondyle of humerus and insertion is base of metacarpal 5

extends and adducts wrist

extensor carpi radialis longus

superficial posterior forearm muscle that is innervated by the radial nerve, origin is lateral epicondyle of the humerus and insertion is metacarpal 2

extends and abducts the wrist

extensor carpi radialis brevis

superficial posterior forearm muscle that is innervated by the radial nerve, origin is the lateral epicondyle of the humerus and the insertion is metacarpal 3

extends and abducts the wrist

extensor digitorum

superficial posterior forearm muscle that is innervated by the radial nerve, origin is lateral epicondyle of the humerus and insertion is middle and distal phalanges 2-5

extends the digits and wrist

extensor digiti minimi

superficial posterior forearm muscle that is innervated by the radial nerve and origin is the lateral epicondyle of the humerus and the insertion is the tendon of extensor digitorum of M5

extends the pinky finger

deep posterior forearm muscles

origin is a forearm bone and innervation is the radial nerve

supinator

abductor pollicis longus

extensor pollicis brevis

extensor pollicis longus

extensor indicis

supinator

deep posterior forearm muscle innervated by the radial nerve, origin is a forearm bone, insertion is proximal radius

supinates the radius

abductor pollicis longus

deep posterior forearm muscle innervated by the radial nerve, origin is a forearm bone, insertion is anterior part of thumb

extensor pollicis brevis

deep posterior forearm muscle innervated by the radial nerve, origin is a forearm bone and insertion is the middle part of the thumb

extensor pollicis longus

deep posterior forearm muscle innervated by the radial nerve, origin is a forearm bone and the insertion is the posterior thumb

extensor indicis

deep posterior forearm muscle innervated by the radial nerve, origin is a forearm bone and the insertion is extensor digitorum tendon of M2

pronation or supination

pronators- pronator teres, pronator quadratus

supinators- biceps brachii and supinator

supinator and pronator quadratus are equal in strength but biceps brachii is stronger than pronator teres making SUPINATION stronger (explains screws)

pure flexion of wrist

flexor carpi radialis, flexor carpi ulnaris

pure extension of wrist

extensor carpi radialis, extensor carpi ulnaris

pure adduction of wrist

flexor carpi ulnaris and extensor carpi ulnaris

pure abduction of wrist

flexor carpi radialis and extensor carpi radialis

thenar muscles of the hand

are intrinsic hand muscles that are innervated by the median recurrent branch of the median nerve, all originate on carpals and insert on thumb bone

abductor pollicis brevis

flexor pollicis brevis

opponens pollicis

hypothenar muscles of the hand

are intrinsic hand muscles that are all innvervated by the ulnar nerve

abductor digiti minimu

flexor digiti minimi

opponens digiti minimi

midpalmar muscles

intrinsic hand muscles all innervated by the ulnar nerve except two first lumbricals

adductor pollicis

lumbricals (lumbricales)

palmar interossei (3)

dorsal interossei (4)

abductor pollicis brevis

thenar muscle that originates on carpals and inserts on thumb bone, innervated by the median recurrent branch of the median nerve

abducts the thumb

flexor pollicis brevis

thenar muscle that originates on carpals and inserts on thumb bone, innervated by the median recurrent branch of the median nerve

flexes the thumb

opponens pollicis

thenar muscle that originates on carpals and inserts on thumb bone, innervated by the median recurrent branch of the median nerve

opposes thumb to other fingers, used for grabbing things

abductor digiti minimi

hypothenar muscle that is innervated by the ulnar nerve, originate on carpals and insert on pinky

abducts the pinky

flexor digiti minimi

hypothenar muscle that is innervated by the ulnar nerve, originate on carpals and insert on pinky

flexes the pinky

opponens digiti minimi

hypothenar muscle that is innervated by the ulnar nerve, originate on carpals and insert on pinky

opposes pinky bones

abductor pollicis

midpalmar muscle innervated by the ulnar nerve, originates on M2 and inserts on the proximal phalynx of thumb

abducts thumb

lumbricals

midpalmar muscles (first two not innervated by ulnar nerve but MEDIAN NERVE), originate on tendons of digitorum profundus and insert on tendons of extensor digitorum

1=index finger and 4=pinky

flex metacarpophalangeal joints and extend interphalangeal joints

palmar interossei (3)

midpalmar muscles innervated by the ulnar nerve and all originate on the metacarpals and insert on middle phalynx of some digit (no middle or thumb)

all adduct digits

dorsal interossei (4)

midpalmar muscels innervated by the ulnar nerve and all originate on metacarpals and insert on middle phalynx of some digit (no thumb)

abducts digits

adduction of fingers

plane is the middle finger, adduction is moving fingers closer to the middle finger ( it cannot be adducted as it is the axis), no matter which way you move middle finger it is abduction