| |
Click Here!
Brachium to Hand Musculature
Muscle Regions of the Body:
Muscle Groups within this Region:
Brachium Musculature
Coracobrachialis
| Origin: coracoid process of the scapula |
| Insertion: medial shaft of the humerus at about its middle |
| Action:
- flexes the humerus
- assists to adduct the humerus
|
| Blood: muscular branches of the brachial artery |
| Nerve: musculocutaneous nerve, C5,6,(C7) |
Biceps brachii
| Origin:
- long head- supraglenoid tubercle and glenohumeral labrum
- short head- tip of the coracoid process of the scapula
|
| Insertion:
- radial tuberosity
- bicipital aponeurosis
|
| Action:
- flexes the forearm at the elbow (when supinated)
- supinates forearm from neutral
- stabilizes anterior aspect of shoulder
- flexes shoulder (weak if at all)
|
| Blood: muscular branches of brachial artery |
| Nerve: musculocutaneous nerve, C5,6 |
Brachialis
| Origin:
- lower 1/2 of anterior humerus
- both intermuscular septa
|
| Insertion:
- ulnar tuberosity
- coronoid process of ulna slightly
|
| Action: elbow flexion (major mover) |
| Blood:
- muscular branches of brachial artery
- radial recurrent artery
|
| Nerve: musculocutaneous nerve, C5,6 |
Triceps brachii
| Origin:
- long head - infraglenoid tubercle of the scapula
- lateral head - upper half of the posterior surface of the shaft of the humerus, and the
upper part of the lateral intermuscular septum
- medial head - posterior shaft of humerus, distal to radial groove and both the medial
and lateral intermuscular septum (deep to the long & lateral heads)
|
| Insertion:
- posterior surface of the olecranon process of the ulna
- deep fascia of the antebrachium
|
| Action:
- long - adducts the arm, extends at the shoulder, and a little elbow flexion
- lateral - extends the forearm at the elbow
- medial - extends the forearm at the elbow
|
| Blood:
- muscular branches of the brachial artery
- superior ulnar collateral artery
- profunda brachii artery
|
| Nerve: radial nerve, C6,7 |
Anconeus
| Origin: posterior surface of the lateral epicondyle of the humerus |
| Insertion: lateral aspect of olecranon extending to the lateral part of ulnar body |
| Action:
- extends the forearm at the elbow
- supports the elbow when in full extension
|
| Blood: middle collateral artery from the profunda brachii artery |
| Nerve: radial nerve, C7,8 |
Antibrachial Flexor Musculature
Pronator teres
| Origin:
- humeral head:
- upper portion of medial epicondyle via the CFT (common flexor tendon)
- medial brachial intermuscular septum
- ulnar head - coronoid process of ulna
- antebrachial fascia
|
| Insertion: lateral aspect of radius at the middle of the shaft (pronator tuberosity) |
| Action:
- pronates forearm (during rapid or forced pronation)
- weakly flexes the elbow
|
| Blood:
- muscular branches of ulnar artery
- muscular branches of radial artery
|
| Nerve: median nerve, C6,7 |
Flexor carpi radialis
| Origin:
- medial epicondyle via the CFT (common flexor tendon)
- antebrachial fascia
|
| Insertion: base of the 2nd and sometimes 3rd metacarpals |
| Action:
- flexes the hand at the wrist
- radially deviates the wrist
- may assist to pronate the forearm
|
| Blood: muscular branches of radial artery |
| Nerve: median nerve, C6,7 |
Palmaris longus
| Origin:
- medial epicondyle via the CFT (common flexor tendon)
- antebrachial fascia
|
| Insertion:
- central portion of the flexor retinaculum
- superficial portion of the palmar aponeurosis
|
| Action: flexes the hand at the wrist |
| Blood: muscular branches of ulnar artery |
| Nerve: median nerve, C6,7 |
Flexor carpi ulnaris
| Origin:
- humeral head - medial epicondyle via the CFT (common flexor tendon)
- ulnar head:
- medial aspect of olecranon
- proximal 3/5 of dorsal ulnar shaft
- antebrachial fascia
|
| Insertion:
- pisiform & hamate bones (via the pisohamate ligament)
- base of the 5th metacarpal (via the pisometacarpal ligament)
|
| Action:
- flexes the hand at the wrist
- ulnarly deviates the wrist
- stabilizes wrist to permit powerful thumb motion
|
| Blood: muscular branches of ulnar artery |
| Nerve: ulnar nerve, C8,T1 |
Flexor digitorum
superficialis
| Origin:
- humeral-ulnar head:
- medial epicondyle via the CFT (common flexor tendon)
- medial boarder of base of coronoid process of ulna
- medial (ulnar) collateral ligament
- antebrachial fascia
- radial head: oblique line of radius along its upper anterior boarder
|
| Insertion: both sides of the base of each middle phalanx of the 4 fingers |
| Action:
- flexes the proximal and middle phalanges
- flexes the wrist if fingers are extended
|
| Blood:
- muscular branches of ulnar artery
- muscular branches of radial artery
|
| Nerve: median nerve, C7,8,T1 |
Flexor digitorum profundus
| Origin:
- anterior & medial surface of upper 3/4 ulna
- adjacent interosseous membrane
|
| Insertion: distal phalanx of medial 4 digits (through FDS tunnel) |
| Action:
- flexes the distal IP joints and in so doing flexes the proximal and middle IP joints
- flexes the wrist if fingers are extended
|
| Blood:
- muscular branches of the ulnar artery
- muscular branches of the radial artery
- anterior interosseous artery (from ulnar artery)
|
| Nerve:
- medial portion - ulnar nerve, C8,T1
- lateral portion - anterior interosseous branch of median nerve, C8,T1
|
Flexor pollicis longus
| Origin:
- middle anterior surface of the radius
- interosseous membrane
- (may also originate from lateral boarder of coronoid process
- or medial epicondyle)
|
| Insertion: palmar aspect of base of the distal phalanx of thumb (deep to flexor
retinaculum) |
| Action:
- flexes the distal phalanx of the thumb (IP joint)
- flexes the other joints to the wrist (McP, CMc and weakly at the wrist)
|
| Blood:
- muscular branches of radial artery
- anterior interosseous artery
|
| Nerve: anterior interosseous branch of median nerve, C8,T1 |
Pronator quadratus
| Origin: distal 1/4 anteriomedial surface of ulna |
| Insertion: distal 1/4 anteriolateral surface of radius |
| Action: pronates the forearm and hand |
| Blood:
- anterior interosseous artery
- muscular branches of the radial artery
|
| Nerve: anterior interosseous branch of median nerve, C8,T1 |
Antibrachial Extensor Musculature
Brachioradialis
| Origin:
- upper lateral supracondylar ridge of humerus (between the triceps and brachialis
muscles)
- lateral intermuscular septum of humerus
|
| Insertion:
- superior aspect of styloid process of radius
- lateral side of the distal 1/2 to 1/3 of the radius
- antebrachial fascia
|
| Action:
- flexes the forearm at the elbow
- pronates the forearm when supinated
- supinates the forearm when pronated
|
| Blood: radial recurrent artery |
| Nerve:
- radial nerve, C5,6 OR
- deep branch of the radial nerve
|
Extensor carpi radialis
longus
| Origin:
- lower lateral supracondylar ridge (below the brachioradialis)
- lateral intermuscular septum of humerus
|
| Insertion: base of 2nd metacarpal |
| Action:
- extends the hand at the wrist
- radially deviates the hand at the wrist
- weakly flexes the forearm at the elbow
- weakly supinates the forearm
|
| Blood: radial recurrent artery |
| Nerve:
- radial nerve, C5,6 OR
- deep branch of the radial nerve
|
Extensor carpi radialis
brevis
| Origin:
- lateral epicondyle via the CET (common extensor tendon)
- radial collateral ligament
- antebrachial fascia
|
| Insertion: base of 3rd metacarpal |
| Action:
- extends the hand at the wrist
- radially deviates the hand at the wrist
|
| Blood: radial recurrent artery |
| Nerve: deep branch of the radial nerve, C6,7 |
Extensor digitorum
| Origin:
- lateral epicondyle via the CET (common extensor tendon)
- antebrachial fascia
|
| Insertion:
- base of middle phalanx of each of the four fingers (central band)
- base of distal phalanx of each of the four fingers (2 lateral bands)
|
| Action:
- extends the four medial digits
- extends the wrist if fingers flexed
- abducts the digits (spreads the digits as it extends them)
|
| Blood: posterior interosseous artery |
| Nerve: posterior interosseous nerve of the radial nerve, C6,7,8 |
Extensor digiti minimi
| Origin:
- lateral epicondyl via the CET (common extensor tendon)
- antebrachial fascia
- ulnar aspect of extensor digitorum
|
| Insertion:
- base of middle phalanx of the 5th digit (central band)
- base of distal phalanx of the 5th digit (2 lateral bands)
|
| Action:
- extends the 5th digit
- abducts the 5th digit
|
| Blood: posterior interosseous artery |
| Nerve: posterior interosseous nerve of the radial nerve, C6,7,8 |
Extensor carpi ulnaris
| Origin:
- 1st head - lateral epicondyle via the CET (common extensor tendon)
- 2nd head - posterior body of ulna
- antebrachial fascia
|
| Insertion: medial side of base of the 5th metacarpal |
| Action:
- extends the hand at the wrist
- ulnarly deviates the hand at the wrist
|
| Blood: posterior interosseous artery |
| Nerve: posterior interosseous nerve of the radial nerve, C6,7,8 |
Supinator
| Origin:
- lateral epicondyle of humerus
- supinator crest of ulna
- radial collateral ligament
- annular ligament
- antebrachial fascia
|
| Insertion: proximal portion of anteriorlateral surface of the radius |
| Action: supinates the forearm |
| Blood: radial recurrent artery |
| Nerve: deep branch of the radial nerve, C6 |
Abductor pollicis longus
| Origin:
- posterior surfaces of ulna and radius
- interosseous membrane
- antebrachial fascia
|
| Insertion: lateral aspect of base of 1st metacarpal |
| Action:
- abducts the 1st metacarpal
- assists to extend & rotate the thumb
- radially deviates the hand at the wrist
- flexes the hand at the wrist
|
| Blood: posterior interosseous artery |
| Nerve: posterior interosseous nerve of the radial nerve, C6,7,(C8) |
Extensor pollicis brevis
| Origin:
- posterior surfaces of radius (below abductor pollicis longus)
- interosseous membrane
- antebrachial fascia
|
| Insertion: base of proximal phalanx of thumb (often a slip inserts into extensor
pollicis longus tendon) |
| Action:
- extends the proximal phalanx and 1st metacarpal of the thumb
- radially deviates the hand at the wrist
|
| Blood: posterior interosseous artery |
| Nerve: posterior interosseous nerve of the radial nerve, C6,7,(C8) |
Extensor pollicis longus
| Origin:
- posterior surface of ulna
- interosseous membrane
- antebrachial fascia
|
| Insertion: distal phalanx of thumb |
| Action:
- extends distal phalanx of thumb
- extends proximal phalanx of thumb
- assists to extend the hand at the wrist (if fingers flexed)
|
| Blood: posterior interosseous artery |
| Nerve: posterior interosseous nerve of the radial nerve, C6,7,8 |
Extensor indicis
| Origin:
- posterior surface of ulna (distal to extensor pollicis longus)
- interosseous membrane
- antebrachial fascia
|
| Insertion: base of middle and distal phalanx of the index finger |
| Action:
- extends the 2nd digit (McP & IP joints)
- adducts the 2nd digit
- assists to extend the hand at the wrist
- stabilizes McP joint for flexion of IP solely
|
| Blood: posterior interosseous artery |
| Nerve: posterior interosseous nerve of the radial nerve, C6,7,8 |
Hand & Wrist Musculature
Abductor pollicis brevis
| Origin:
- distal border of flexor retinaculum
- trapezium (may be variable)
|
| Insertion:
- lateral aspect of base of proximal phalanx of the thumb
- may also send a slip to the tendon of extensor pollicis longus
|
| Action:
- abducts thumb (at the McP joint)
- participates to flex the thumb (at the McP joint)
- if attached to extensor pollicis longus, it might assist to extend the thumb
|
| Blood: superficial palmar branches of radial artery |
| Nerve: recurrent branch of median nerve, C8,T1 |
Flexor pollicis brevis
| Origin:
- superficial head:
- distal border of flexor retinaculum
- trapezium
- deep head:
- floor of carpal tunnel
- indirectly to scaphoid & trapezium
|
| Insertion:
- base of proximal phalanx of thumb
- can also attach to the lateral sesamoid bone at the McP joint
|
| Action: powerfully flexes the thumb (at the McP joint) |
| Blood: superficial palmar branches of radial artery |
| Nerve:
- superficial head - recurrent branch of median nerve, C8,T1
- deep head - deep branch of ulnar nerve, C8,T1
|
Opponens pollicis
| Origin:
- distal border of flexor retinaculum
- trapezium
|
| Insertion: lateral aspect of the 1st metacarpal |
| Action: opposes the thumb to the fingers |
| Blood: superficial palmar branches of radial artery |
| Nerve: recurrent branch of median nerve, C8,T1 |
Adductor pollicis
| Origin:
- transverse head: 3rd metacarpal
- oblique head:
- base of 1st, 2nd and 3rd metacarpals
- floor of carpal tunnel
|
| Insertion:
- medial aspect of the base of proximal phalanx
- medial sesamoid at McP
|
| Action:
- adducts the thumb
- may assist to flex the thumb (at the McP joint)
|
| Blood: superficial palmar branches of radial artery |
| Nerve: deep branch of ulnar nerve, C8,T1 |
Palmaris brevis
| Origin: medial margin of palmar aponeurosis |
| Insertion:
- skin of ulnar border of palm
- may insert on the pissiform
|
| Action: tenses the skin on the ulnar side, which is used in a grip action |
| Blood: superficial palmar branches of ulnar artery |
| Nerve: superficial branch of ulnar nerve, C8,T1 |
Abductor digiti minimi
| Origin: pisiform & tendon of flexor carpi ulnaris |
| Insertion:
- medial aspect of the base of proximal phalanx of the 5th digit
- may send a slip to the ulnar side of the dorsal expansion
|
| Action:
- abduct 5th digit (requires pisiform stabilized by FCU)
- assists to flex the 5th digit (at McP)
- may assist in extension of 5th digit (at IP due to slips to extensor digitorum)
|
| Blood: deep palmar branches of ulnar artery |
| Nerve: deep branch of ulnar nerve, C8,T1 |
Flexor digiti minimi brevis
| Origin:
- distal border of flexor retinaculum
- hook of the hamate
|
| Insertion: medial aspect of the base of proximal phalanx |
| Action: flexes the 5th digit (at the McP joint) |
| Blood: deep palmar branches of ulnar artery |
| Nerve: deep branch of ulnar nerve, C8,T1 |
Opponens digiti minimi
| Origin:
- distal border of flexor retinaculum
- hook of the hamate
|
| Insertion: medial aspect of the 5th metacarpal |
| Action:
- opposes the 5th digit with the thumb
- assists to "cup" the palm
|
| Blood: deep palmar branches of ulnar artery |
| Nerve: deep branch of ulnar nerve, C8,T1 |
Palmar interossei
| Origin: from the side of the metacarpal that faces the midline - to adduct them |
| Insertion:
- on the base of the proximal phalanx of the digit of origin (same side toward the
midline)
- extensor hood of the same digit(s)
|
| Action:
- adducts the fingers (hint: PAD)
- flexes the fingers (at the McP while IP joints are extended)
|
| Blood: palmar metacarpal artery of deep palmar arch |
| Nerve: deep branch of ulnar nerve, C8,T1 |
Dorsal interossei
| Origin: between each metacarpal |
| Insertion:
- directly distal to the origin on the base of the proximal phalanx closest to the midline
(to abduct them.)
- extensor hood of the same digit(s)
|
| Action:
- abducts the fingers (hint: DAB)
- flexes the fingers (at the McP while IP joints are extended)
|
| Blood: palmar metacarpal artery of deep palmar arch |
| Nerve: deep branch of ulnar nerve, C8,T1 |
Lumbricals
| Origin:
- tendon of flexor digitorum profundus
- 1 & 2 have a single head of origin (from radial aspect of tendon)
- 3 & 4 have two heads of origin (each head from an adjacent tendon)
|
| Insertion: extensor hood of digits 2-5 |
| Action:
- flexes the fingers (at the McP joints)
- extend IPs
|
| Blood: palmar metacarpal arteryof deep palmar arch |
| Nerve:
- 1 & 2 - median nerve, C8,T1
- 3 & 4 - deep branch of ulnar nerve, C8,T1
|
|