Pronunciation (eks-TEN-sor dij-I-TOR-um) Origin/Proximal Attachment Lateral epicondyle via the common extensor tendon; antebrachial fascia Insertion/Distal Attachment Base of middle phalanx of each of the 4 fingers (central band); base of distal phalanx of each of the 4 fingers (2 lateral bands) Action/Relevance Extends the 4 medial digitsExtends the wristAbducts the digits (spreads them as it extends them) Innervation Radial nerve - posterior interosseous (C6, 7,8) | 
