Flexor Digitorum Superficialis

Origin (2 heads):
Humeroulnar head: Common flexor - medial epicondyle, ulnar collateral ligament, tubercle on medial border of coronoid process
Radial head: anterior aspect of radial head

Course:
At wrist arranged in superfial pair (3 & 4 digit) and deep pair (2 & 5 digit)
Deep to flexor retinaculum, enclosed within ulnar bursa

Insertion:
Ends in 4 tendons for 2-5 digits
Tendon splits opposite proximal phalanx into medial and lateral slips and insert into middle phalanx

Relations:
Fibrous arch between 2 heads
Anterior interosseous nerve (median N branch) and ulnar artery pass deep to the fibrous arch
The tendons lie medial to palmaris longus and lateral to ulnar N and vessels

Nerve supply:
Median nerve

Action:
Flexion of PIPJ
May flex MCPJ