Anterior forearm muscles

Question 1

Pronator teres (PT)

Answer 1

Origin - ulnar head : coronoid process of ulna
- humeral head : medial epicondyle of humerus
Insertion - middle of convexity of lateral surface of radius
Innervation - median nerve C6, C7
Action - pronates and flexes forearm

Question 2

Flexor carpi radialis (FCR)

Answer 2

Origin - medial epicondyle of humerus
Insertion - base of 2nd (3rd) metacarpal
Innervation- median nerve C6, C7
Action - flexes and abducts hand at wrist

Question 3

Palmaris longus

Answer 3

Origin - medial epicondyle of humerus
Insertion - distal half of flexor retinaculum, palmar aponeurosis
Innervation- median nerve C7, C8
Action - flexes hand (at wrist) and tenses palmar aponeurosis

Question 4

Flexor carpi ulnaris (FCU) : humeral and ulnar head

Answer 4

Origin - olecranon and posterior border of ulna via aponeurosis
Insertion - pisiform, hook of hamate, 5th metacarpal
Innervation- ulnar nerve (C7, C8)
Action - flexes and adducts hand at wrist

Question 5

Flexor digitorum superficialias (FDS)

Answer 5

Origin - humeral-ulnar head - medial epicondyle of humerus and coronoid process of ulna
- radial head - oblique line of radius
Insertion - shafts (bodies) of middle phalanges of medial four digits
Innervation- median nerve C7,C8,T1
Action - flexes wrist joint
- flexes proximal interphalangeal joints of middle four digits
- acting more strongly, it also flexes proximal phalanges at
metacarpophalangeal joints

Question 6

Flexor digitorum profundus (FDP)

Answer 6

Origin - proximal three quarters of medial and anterior surfaces of ulna and interosseous membrane
Insertion - bases of distal phalanges of 2nd, 3rd, 4th, and 5th digits
Innervation- lateral part (to digits 2 and 3) : median nerve (C8, T1) (anterior interosseous branch)
- medial part (to digits 4 and 5) ulnar nerve (C8, T1)
Action - flexes wrist joint
- flexes distal interphalangeal joints of digits 2,3,4,5,
- assist with wrist flexion

Question 7

Flexor pollicus longus (FPL)

Answer 7

Origin - anterior surface of radius and adjacent interosseous membrane
Insertion - base of distal phalanx of thumb
Innervation- anterior interosseous nerve from median nerve C8, T1
Action - flexes wrist
- flexes metacarpophalangeal and interphalangeal joints of thumb

Question 8

Pronator quadratus

Answer 8

Origin - distal quarter of anterior surface of ulna
Insertion - distal quarter of anterior surface of radius
Innervation - anterior interosseous nerve from median nerve C8, T1
Action - pronates forearm
- deep fibers bind radius and ulna together