What are the origin, insertion, and primary action of the flexor digitorum superficialis?

• A. Origin: medial epicondyle of the humerus and coronoid process of ulna; Insertion: middle phalanges of digits II–V; Action: flexes PIP joints of digits II–V and assists in wrist flexion.
• B. Origin: lateral epicondyle of the humerus; Insertion: base of the 5th metacarpal; Action: extends and adducts the wrist.
• C. Origin: medial epicondyle of the humerus; Insertion: distal phalanges of digits II–V; Action: flexes DIP joints of digits II–V.
• D. Origin: temporal fossa; Insertion: coronoid process of mandible; Action: elevates and retracts the mandible.

Answer: (A)