Muscles of the forearm and hand Flashcards
What are the 2 components of the forearm?
Anterior (flexor-pronator) and
Posterior (extensor-supinator)
What is the origin of the pronator teres?
Humeral Head: Medial epicondyle of humerus
Ulnar Head: Coronoid process of ulna
What is the insertion of pronator teres?
Middle of lateral surface of radius
What is the innervation of pronator teres?
Median nerve (C6, C7)
What is the action of pronator teres?
Pronates and flexes elbow
Flexor-pronator muscles are divided into two groups: what are they?
Superficial group of muscles (5):
(Cross the elbow joint)
Deep group of muscles (3):
(Do not cross the elbow joint)
What are the superficial group of muscles of the forearm? (Flexor-pronator)
Pronator teres
Flexor carpi radialis
Palmaris longus
Flexor carpi ulnaris
Flexor digitorum superficialis – second layer
What are the deep group of muscles of the forearm? (Flexor-pronator)
Flexor digitorum profundus
Flexor pollicis longus
Pronator quadratus
What is the origin of the Flexor Carpi Radialis?
Medial epicondyle of humerus
What is the insertion of the Flexor Carpi Radialis?
Base of 2nd metacarpal
What is the innervation of the Flexor Carpi Radialis?
Median nerve (C6, C7)
What is the action of the Flexor Carpi Radialis?
Flexes and abducts wrist
What is the origin of Palmaris Longus?
Medial epicondyle of humerus
What is the insertion of Palmaris Longus?
Distal half of flexor retinaculum and palmar aponeurosis
What is the innervation of Palmaris Longus?
Median nerve (C6, C7)
What is the action of Palmaris Longus?
Flexes wrist and tightens palmar aponeurosis
(absent in 14% of the population)
What is the origin of Flexor Carpi Ulnaris?
Humeral head: Medial epicondyle of humerus
Ulnar head: Olecranon and posterior border of ulna
What is the insertion of Flexor Carpi Ulnaris?
Pisiform, hook of hamate, 5th metacarpal
What is the innervation of Flexor Carpi Ulnaris?
Ulnar nerve (C7, C8)
What is the action of Flexor Carpi Ulnaris?
Flexes and adducts wrist
What is the origin of Flexor Digitorum Superficialis?
Humeroulnar head: Medial epicondyle of humerus, ulnar collateral ligament, coronoid process of ulna
Radial head: Superior half of anterior border of radius
What is the insertion of Flexor Digitorum Superficialis?
Bodies of middle phalanges of medial four digits
What is the innervation of Flexor Digitorum Superficialis?
Median nerve (C7, C8, T1)
What is the action of Flexor Digitorum Superficialis?
Flexes proximal interphalangeal joints of medial four digits; acting more strongly it also flexes the metacarpophalangeal joints
What is the origin of Flexor Digitorum Profundus?
Proximal three fourths of medial and anterior surfaces of ulna and interosseous membrane
What is the insertion of Flexor Digitorum Profundus?
Base of distal phalanges of medial four digits
What is the innervation of Flexor Digitorum Profundus?
Medial part: ulnar nerve (C8, T1)
Lateral part: median nerve (C8, T1)
What is the innervation of Flexor Digitorum Profundus?
Flexes distal interphalangeal joints of medial four digits; assists with flexion of the hand
What is the origin of Flexor Pollicis Longus?
Anterior surface of radius and adjacent interosseous membrane
What is the insertion of Flexor Pollicis Longus?
Base of distal phalanx of thumb
What is the innervation of Flexor Pollicis Longus?
Anterior interosseous nerve from median (C8, T1)
What is the action of Flexor Pollicis Longus?
Flexes interphalangeal joint of thumb
What is the origin of Pronator Quadratus?
Distal fourth of anterior surface ulna
What is the insertion of Pronator Quadratus?
Distal fourth of anterior surface of radius
What is the innervation of Pronator Quadratus?
Anterior interosseous nerve from median (C8, T1)
What is the action of Pronator Quadratus?
Pronates forearm; deep fibres bind radius and ulna together
What are the superficial muscles of the extensor-supinator muscles?
Brachioradialis
Extensor carpi radialis longus
Extensor carpi radialis brevis
Extensor digitorum
Extensor digiti minimi
Extensor carpi ulnaris
What are the deep muscles of the extensor-supinator muscles?
Supinator
Abductor pollicis longus
Extensor pollicis brevis
Extensor pollicis longus
Extensor indicis
What muscles Extend Abduct and adduct the wrist?
Extensor Carpi Radialis longus
Extensor Carpi Radialis brevis
Extensor Carpi Ulnaris
Which muscles extend the medial 4 digits?
Extensor digitorum
Extensor Indicis
Extensor digiti minimi
Which muscles extend and abduct the first digit?
Abductor Pollicis longus
Extensor pollicis brevis
Extensor pollicis longus
What is the origin of Brachioradialis?
Proximal two thirds of the lateral supracondylar ridge of humerus
What is the insertion of Brachioradialis?
lateral surface of radius proximal to the radial styloid
What is the innervation of Brachioradialis?
Radial nerve (C6, C7)
What is the action of Brachioradialis?
Weak flexor of the forearm, maximal when the forearm is in midpronated position
What are Muscles that extend and abduct (1) or adduct the hand at the wrist (2)?
1 Extensor carpi radialis longus and Extensor carpi radialis brevis
2 Extensor carpi ulnaris
What is the origin of Extensor Carpi Radialis Longus?
Lateral supracondylar ridge of humerus and a few fibres from
the lateral epicondyle
What is the insertion of Extensor Carpi Radialis Longus?
Base of 2nd metacarpal
What is the innervation of Extensor Carpi Radialis Longus?
Radial nerve (C6, C7)
What is the action of Extensor Carpi Radialis Longus?
Extend and abduct wrist
What is the origin of Extensor Carpi Radialis Brevis?
Lateral epicondyle of humerus
What is the insertion of Extensor Carpi Radialis Brevis?
Base of 3rd metacarpal
What is the innervation of Extensor Carpi Radialis Brevis?
Deep branch of radial nerve (C7, C8)
What is the action of Extensor Carpi Radialis Brevis?
Extend and abduct wrist