Thoracic limb - Flexor group OIAs

Flexor carpi radialis m.

Origin: medial epicondyle of the humerus

Insertion: palmar base of 2nd and 3rd metacarpal bones

Action: flex the carpal joints

Superficial digital flexor m. (SDF)

Origin: medial epicondyle of the humerus

Insertion: palmar bases of the middle phalanges

Action: flex the carpal joints; flex the metacarpophalangeal joints; flex the proximal interphalangeal joints

Flexor carpi ulnaris m.

Origin: medial epicondyle of the humerus, olecranon of the ulna

Insertion: accessory carpal bone

Action: flex the antebrachiocarpal joint

Deep digital flexor m. (DDF)

Origin:

- Ulnar head: (1) body of the ulna

- Humeral head: (2) medial epicondyle of the humerus;

- Radial head: (3) body of the radius; •

Insertion: flexor tubercles of the distal phalanges

Action: flex the carpal joints; flex the digital joints

Pronator teres m.

Origin: medial epicondyle of the humerus

Insertion: body of radius

Action: pronation of the manu

Pronator quadratus m.

Attachments: apposed surfaces of the radius and the ulna

Action: pronation of the manus

Interossei mm.(4 total) or interosseus m. (singular)

Origin: palmar base of respective metacarpal bone

Insertion: proximal sesamoid bones & palmar base of respective proximal phalanx (tendon of common digital extensor dorsally via extensor branch)

Action: supports and flex metacarpophalangeal joint