L9: Anterior Forearm

Question 1

All muscles of the forearm are innervated by the __________ except for the flexor carpi ulnaris muscle & the medial half of the flexor digitorum profundus muscle which are innervated by the ___________

Answer 1

All muscles of the forearm are innervated by the median nerve except for the flexor carpi ulnaris muscle & the medial half of the flexor digitorum profundus muscle which are innervated by the ulnar nerve

Question 2

Answer 2

Question 3

Superficial Muscles of the Flexor Compartment of Forearm

Common Origin point?

Answer 3

• Pronator Teres: Doesn’t extend into hand like others
• Flexor carpi radialis
• Palmaris Longus
• Flexor carpi ulnaris

Shared Origin: Common flexor of medial epicondyle of the humerus

Question 4

Superficial Group (P/F/P/F)

_______________ ______________ ______________ __________

Answer 4

Superficial Group (P/F/P/F)

• Pronator Teres
• Flexor carpi radialis
• Palmaris Longus
• Flexor carpi ulnaris

Question 5

Pronator Teres

Origin, Insertion, Innervation, Action

Answer 5

Origin: Medial Epicondyle of Humerus and Medial border of the Coronoid Process of the ulna

Insertion: Mid-lateral surface of the radial shaft

Innervation: Median nerve

Action: Pronates & flexes forearm

Question 6

Flexor Carpi Radiallis

Origin, Insertion, Innervation, Action

Answer 6

Origin: Medial Epicondyle of Humerus through common flexor tendon

Insertion: Bases of Metacarpals 2 and 3

Innervation: Median Nerve

Action: Flexes and abducts hand at the wrist joint.

Question 7

Palmaris Longus

Origin, Insertion, Innervation, Action

Answer 7

Origin: Medial Epicondyle of Humerus through common flexor tendon

Insertion: Flexor retinaculum and Palmar aponeurosis

Innervation: Median Nerve

Action: Accessory flexor of the wrist joint.

Missing in 10-15% of people, very superficial, commonly damanged in cutting victims

Question 8

Flexor Carpi Ulnaris

Origin, Insertion, Innervation, Action

Answer 8

Origin: Medial Epicondyle of Humerus through common flexor tendon and Medial border of Olecranon of Ulna

Insertion: Pisiform, Hook of Hamate, and Bases of Metacarpal 5

Innervation: Ulnar Nerve

Action: Powerful flexion and adduction wrist

Question 9

Intermediate Group:

_________________

Answer 9

Intermediate Group:

Flexor Digitorum Superficialis

Question 10

Flexor Digitorum Superficialis

Origin, Insertion, Innervation, Action

Answer 10

Origin:

•Medial Epicondyle of Humerus through common flexor tendon

• Cornonoid Process of Ulna
• Anterior Surface of Radial Shaft

Insertion: _(_4 Tendons) Middle phalanges of digits 2-5

Innervation: Median Nerve

Action: Flexes middle phalanges 2-5, proximal phalanges & wrist

*Tendons of Superficialis splits in 2 - to permit profundus passing through

Question 11

Deep Group (Forearm)

__________ ____________ ____________

Answer 11

Deep Group:

• Flexor Pollicis longus
• Flexor Digitorum Profundus
• Pronator Quadratus

Question 12

Flexor Pollicis Longus

Origin, Insertion, Innervation, Action

Answer 12

Origin:

•Medial Epicondyle of Humerus

•Anterior Surface of Radial Shaft

Insertion: Base of distal phalanx of thumb

Innervation: Median Nerve

Action: Flexes Thumb

Question 13

Flexor Digitorum Profundus

Origin, Insertion, Innervation, Action

Answer 13

Origin: Upper ¾ anterior shaft of ulna

Insertion: Base of distal phalanges 2-5 through tendons of flexor digitorum superficialis

Innervation: Median Nerve (Index & Middle), Ulnar Nerve (Ring & Pinky)

Action: Flexes Distal phalanges 2-5

Question 14

Pronator Quadratus

Origin, Insertion, Innvervation, Action

Answer 14

Origin: Distal ⅓anterior surface of Ulna

Insertion: Distal ¼anterior surface of radius

Innervation: Median Nerve

Action: Pronates Forearm (Pulls distal end of radius anteriorly over ulna)