UE Origin and Insertion: Forearm Muscles

Pronator teres

2 heads: humeral head and ulnar head Humeral head origin: directly superior to the medial epicondyle of the humerus. Ulnar head: medial side of the coronoid process of the ulna. Insertion: mid-lateral surface of the radius. Action: pronates the forearm, palm turns posterior. Assists in flexion of the forearm at the elbow. Innervation: median nerve

The flexor carpi ulnaris ___________.

Adducts the wrist

The smallest of the posterior extensors of the elbow joint is the __________.

Anconeus

At the completion of supinator action, the palm is turned __________.

Anteriorly

Muscles that flex the forearm are placed

Anteriorly

Forearm supination is assisted by the __________.

Biceps brachii

Forearm supination synergist

Biceps brachii

Largest forearm flexor

Biceps brachii

Prime mover of elbow flexion

Brachialis

The muscle that generates the most power during elbow flexion is the __________.

Brachialis

Synergists of elbow flexion

Brachioradialis and biceps brachii

Flexor reinaculum creates a tight space through which the tendons must pass prior to reaching their insertion sites called _____________.

Carpel tunnel

The forearm muscles can be divided into anterior flexors and posterior extensors, as well as __________.

Deep and superficial layers

The prime mover of wrist extension is the __________.

Extensor digitorum

Movement of the elbow joint movement is limited to __________.

Flexion and extension

Prime movies are wrist flexion are

Flexor carpi radialis, flexor carpi ulnaris, and flexor digitorum superficialis

Finger flexion occurs through combined action of the

Flexor digitorum profundus, flexor pollicis longus, and flexor digitorum superficialis

All of the tendon of the long flexor muscles are held in place at the wrist by a thickening of the deep fascia called _____________.

Flexor retinaculum

Wrist abduction occurs through the actions of __________ muscles.

Four

The insertion of the extensor digitorum branches into ___________.

Four tendons

The elbow is a __________ joint.

Hinge

What are the three heads of the flexor digitorum superficialis?

Humeral, radial, and ulnar

The origin of the flexor carpi radialis is on the __________.

Humerus

Carpal tunnel syndrome is characterized by ___________.

Inflammation of the flexor retinaculum and/or tendon sheaths

The origin of the long head of the triceps brachii is on the ___________.

Infraglenoid tubercle of the scapula

An origin of the supinator is the __________.

Lateral epicondyle of the humerus

The insertion of the extensor carpi radialis longus muscle is on _____________.

Metacarpal two

Which of the following statements about muscles of the elbow joint is true?

None of these statements is correct The biceps brachii is a posterior extensor. The biceps brachii has two heads that share the same origin site. The brachioradialis originates and inserts on the ulna. None of these are correct.

Pronator quadratus

Origin: distal anterior surface of ulna Insertion: distal anterior surface of radius Action: forearm pronation Innervation: median nerve

Supinator

Origin: lateral epicondyle of humerus, radial collateral ligament, annular ligament, and supinator crest of the ulna near the radial notch. Insertion: proximal one third of the radius. Action: Supination of the forearm, palm turns anterior. Innervation: radial nerve

Anconeus

Origin: lateral epicondyle of the humerus. Insertion: olecranon process of the ulna. Action: extension of the forearm at the elbow. Innervation: radial nerve

Brachioradialis

Origin: lateral supracondylar ridge of the humerus. Insertion: base of the styloid process of the radius. Action: flexion of the forearm at the elbow. Innervation: radial nerve

Synergists of wrist flexion are

Palmaris longus and flexor pollicis longus

Muscles that extend the forearm are placed

Posteriorly

Movement of the forearm includes __________.

Pronation and supination

Muscles in the forearm that function in pronation and supination

Pronator quadratura, pronator teres, and supinator

Of all the flexor muscles of the forearm, the __________ is the shortest.

Pronator teres

The two heads of the biceps brachii combine to insert on the __________.

Radial tuberosity

To allow movement of the tendons within the carpal tunnel zone, each tendon is encased in a __________.

Sheath

Extensor digitorum

Superficial extensor muscle occupying the posterior compartment of the forearm. Origin: common extensor tendon on anterior surface of lateral epicondyle of humerus. Insertion: extensor expansions on the dorsal of digits 2-5. Action: extension of all joints of digits 2-5. Assists in wrist extension. Innervation: radial nerve

Extensor carpi radialis brevis

Superficial extensor muscle occupying the posterior compartment of the forearm. Origin: common extensor tendon on the anterior surface of the lateral epicondyle of the humerus. Insertion: dorsal surface of the base of metacarpal 3. Action: extension and assists in abduction of the wrist. Innervation: radial nerve

Extensor carpi radialis longus

Superficial extensor muscle occupying the posterior compartment of the forearm. Origin: distal one third of the lateral supracondylar ridge of the humerus. Insertion: dorsal surface of the base of metacarpal 2. Action: extension and abduction of the wrist. Innervation: radial nerve

Flexor carpi ulnaris

Superficial flexor muscle occupying the anterior compartment of the forearm. 2 heads: Humeral and Ulnar Humeral head origin: common flexor tendon of the medial epicondyle of the humerus. Ulnar head origin: by an aponeurosis from the proximal two thirds of the posterior ulna. Insertion: pisiform bone and by ligaments to the hamate bone and metacarpal 5. Action: Flexion and adduction of the wrist. Innervation: ulnar nerve

Flexor digitorum superficialis

Superficial flexor muscle occupying the anterior compartment of the forearm. 3 heads: humeral head, ulnar head, and radial head. Humeral head origin: common flexor tendon of the medial epicondyle of the humerus. Ulnar head origin: medial side of the coracoid process of the ulna. Radial head origin: oblique line of radius. Insertion: by four tendons to the middle phalanges of digits 2-5. Action: flexion of the proximal interphalangeal joints of digits 2-5. Innervation: median nerve

Flexor carpi radialis

Superficial flexor muscle occupying the anterior compartment of the forearm. Origin: common flexor tendon of medial epicondyle of the humerus. Insertion: base of metacarpal 2 and by a tendons slip to the base of metacarpal 3. Action: flexion and abduction of the wrist. Innervation: median nerve.

Forearm supination is cause by

Supinator muscle

Which of the following statements about muscles of the forearm is true?

The pronator teres originates on the medial epicondyle and inserts on the radius

Why are the muscles that move the fingers and wrist located in the forearm?

This design allows the hand to maintain fine motor control and strength without the interference of bulky muscles

The prime mover of elbow extension is the __________.

Triceps brachii

The actions of the extensor carpi radialis brevis are localized to the_________.

Wrist

Forearm extensors

ancones and triceps brachii

Synergists of wrist flexion

extensor carpi radialis longus, extensor carpi radialis brevis, and extensor carpi ulnaris

Wrist adduction occurs through two muscles:

extensor carpi ulnaris and flexor carpi ulnaris

Finger extension occurs through the combine actions of the

extensor pollicis longus, extensor pollicis brevis, extensor indicis, and extensor digitorum

Wrist abduction occurs through four muscles:

flexor carpi radialis, abductor pollicis longus, extensor carpi radialis brevis, and extensor carpi radialis longus