Which muscle originates from the lateral supracondylar ridge and inserts on the base of the 2nd metacarpal with the action of extending and abducting the wrist?

• A. Extensor carpi radialis longus
• B. Flexor digitorum superficialis
• C. Extensor carpi ulnaris
• D. Flexor carpi radialis

Answer: (A)

Extensor carpi radialis longus fits the description because it starts from the lateral supracondylar ridge of the humerus and inserts on the base of the second metacarpal. Its action is to extend the wrist and abduct (radially deviate) the hand. This combination of origin, insertion, and movement matches exactly: a wrist extensor that pulls the hand toward the thumb side.

The other options don’t align with one or more of these features: they either originate from a different part of the humerus (like the lateral epicondyle or the medial epicondyle), insert on a different metacarpal, or primarily flex the wrist rather than extend it.