Answer:
is primarily responsible for a movement
Explanation:
Working muscles are called agonists or prime movers because to complete a movement they produce major force. These muscles are primarily responsible for the occurrence of a movement. By contracting they make a range of motion for example during the up phase of push up the triceps brachii contracts which produce a shortening contraction.
The muscles that oppose the action of agonists are called antagonists. So antagonists are responsible for the returning of arm or leg in its original position. So the correct answer is- is primarily responsible for a movement.
