In muscle actions, what term describes the muscle that provides the major force (primary mover) for a specific movement?

• A. Fixator
• B. Synergist
• C. Antagonist
• D. Agonist

Answer: (D)

Verified step by step guidance

1. Understand the roles of different muscles during movement: muscles can act as agonists, antagonists, synergists, or fixators depending on their function in the action.
2. Define the term 'agonist': it is the muscle primarily responsible for producing a specific movement, often called the 'primary mover'.
3. Define 'antagonist': this muscle opposes the action of the agonist, relaxing while the agonist contracts to allow smooth movement.
4. Define 'synergist': these muscles assist the agonist by adding extra force or reducing unwanted movements.
5. Define 'fixator': these muscles stabilize the origin of the agonist so that it can act more efficiently.