Flexor Pollicus Longus
O: Middle half, anterior aspect of radius and adjacent interosseous membrane
I: Base of distal phalanx of the thumb
In: Median
Flexor of the interphalangeal joint of the thumb
Flexor Digitorum Superficialis (Intermediate Group)
Origin: Humeral head: Medial epicondyle of humerus
Ulnar head: Coronoid process of ulna
Radial head: Anterior oblique line of radius
I: 2 slips on the sides of the middle phalanges (2-5)
In: Median
F: Flexion of PIP of 4 fingers, assists wrist and MCP flexion
Flexor Digitorum Profundus
O: Anteriomedial aspect of proximal 2/3rds ulna and adjacent interosseus membrane
I: Base of distal phalanges (2-5)
In: Median (lateral half)
Ulnar (medial half)
F: Flexion of distal phalanges of 4 fingers at DIP flexion, assist in PIP, MCP, wrist flex
Pronator Quadratus
O: Distal 1/4 anterior aspect of ulna
I: Distal 1/4 anterior aspect of radius
In: Median
F: Forearm pronation