Question

When the forearm is extended at the elbow joint the _muscle acts as the prime mover (antagonist).

A) biceps brachii
B) triceps brachii
C) brachialis
D) brachioradialis

Answer 1

The triceps brachii is the muscle that extends the forearm at the elbow joint.

Step-by-step explanation:

The muscle that extends the forearm is the triceps brachii. The triceps brachii is located on the back of the upper arm and is responsible for extending the forearm at the elbow joint. When the forearm is extended, the triceps brachii acts as the prime mover or antagonist.