Which muscle has an origin from the lateral epicondyle of the humerus and the annular ligament?

Which muscle has an origin from the lateral epicondyle of the humerus and the annular ligament?

• A. Supinator
• B. Pronator Teres
• C. Flexor Digitorum Superficialis
• D. Extensor Carpi Ulnaris

Answer: (A)

Supinator is the muscle that has that combined origin from the lateral epicondyle of the humerus and the annular ligament. The muscle splits into superficial and deep parts that wrap around the proximal radius, inserting on the upper part of the radius itself. This arrangement lets it rotate the forearm to turn the palm upward (supination), especially when the elbow is bent. The annular ligament helps form part of its origin and also stabilizes the proximal radioulnar joint by keeping the radial head in place. The other muscles listed come from different origins (medial epicondyle or ulna) and do not include the annular ligament in their origin, so they don’t fit this combination.

Supinator is the muscle that has that combined origin from the lateral epicondyle of the humerus and the annular ligament. The muscle splits into superficial and deep parts that wrap around the proximal radius, inserting on the upper part of the radius itself. This arrangement lets it rotate the forearm to turn the palm upward (supination), especially when the elbow is bent. The annular ligament helps form part of its origin and also stabilizes the proximal radioulnar joint by keeping the radial head in place. The other muscles listed come from different origins (medial epicondyle or ulna) and do not include the annular ligament in their origin, so they don’t fit this combination.